Detailed Description
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. It should be understood that the description is only illustrative and is not intended to limit the scope of the invention. In the following detailed description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the embodiments of the invention. It may be evident, however, that one or more embodiments may be practiced without these specific details. In addition, in the following description, descriptions of well-known structures and techniques are omitted so as not to unnecessarily obscure the present invention.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The terms "comprises," "comprising," and/or the like, as used herein, specify the presence of stated features, steps, operations, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, or components.
All terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art unless otherwise defined. It should be noted that the terms used herein should be construed to have meanings consistent with the context of the present specification and should not be construed in an idealized or overly formal manner.
Where a convention analogous to "at least one of A, B and C, etc." is used, in general such a convention should be interpreted in accordance with the meaning of one of skill in the art having generally understood the convention (e.g., "a system having at least one of A, B and C" would include, but not be limited to, systems having a alone, B alone, C alone, a and B together, a and C together, B and C together, and/or A, B, C together, etc.).
In the technical scheme of the invention, related user information (including but not limited to user personal information, user image information, user equipment information, such as position information and the like) and data (including but not limited to data for analysis, stored data, displayed data and the like) are information and data authorized by a user or fully authorized by all parties, and the related data are collected, stored, used, processed, transmitted, provided, invented, applied and the like, all processed according to related laws and regulations and standards, necessary security measures are adopted, no prejudice to the public order is provided, and corresponding operation entries are provided for the user to select authorization or rejection.
Today, where network security is increasingly emphasized, quantum key distribution technology is used as an emerging key communication technology, and is widely applied to network security work by means of unique true randomness, indecipherability, communication mode security and traceability. The free space quantum key distribution, in particular the star-ground quantum key distribution, can effectively realize the global quantum key distribution. The quantum channel and the classical channel of the free space quantum key distribution in the prior art are separated, the classical channel uses a microwave data transmission mode, and the microwave data transmission station and the ground optical station cannot work simultaneously because the microwave data transmission station and the ground optical station are not located at the same place, so that real-time key extraction cannot be realized, the key extraction needs to be processed off-line after the fact, and the key extraction is limited by measurement and control resources, and the final safe code formation can be completed by only a few days for one key extraction.
However, in the process of transmitting the quantum key by using the space channel, due to the complexity of the space channel, the influence of factors such as weather, unstable link and the like, the synchronization signal may be lost, and the defects of multiple bit errors and multiple interruption may exist in the data transmission process are caused. In the research and development process, research and development personnel find that in the related technology, as the quantum key is distributed through a classical channel and a quantum channel for transmission respectively, a receiving end cannot extract the quantum key in real time and quickly according to encryption information, and as a space channel is unstable, the technical problem of low bit rate of the quantum key and the encryption information in the process of transmitting by using the space channel is solved.
In view of the above, the embodiment of the invention provides a method for real-time code formation of quantum key distribution applicable to free space, which is characterized by being applied to a receiving end and comprising the steps of responding to received light quantum streams and laser signals, detecting the light quantum streams by utilizing a plurality of measuring basis vectors to obtain quantum original detection signals, wherein the light quantum streams and the laser signals are obtained by transmitting ends through laser communication channels in the free space, the laser signals comprise a plurality of synchronous coding information and a plurality of modulating basis vectors, generating a plurality of original key information data packets according to the plurality of synchronous coding information and the plurality of measuring basis vectors, transmitting the plurality of original key information data packets to the transmitting end through the laser communication channels, obtaining basis vectors and comparing key data by utilizing low-density parity check codes, generating a plurality of intermediate key information data packets by utilizing the transmitting end through laser communication channels, amplifying the basis vectors in the basis data packets according to the low-density parity check codes, obtaining a plurality of the intermediate key information packets, amplifying the basis vectors and obtaining the intermediate key information data, and obtaining the intermediate key information data by utilizing the low-density parity check codes, and amplifying the basis of the intermediate key information data, and obtaining the intermediate key information data by the transmitting the intermediate key information data packets, and the intermediate key information data.
Fig. 1 shows an application scenario diagram of a method for real-time encoding of a free-space quantum key distribution according to an embodiment of the present invention.
As shown in fig. 1, the application scenario according to this embodiment may include a first terminal device 101, a quantum optical channel 102, and a second terminal device 103. The first terminal device 101 is configured to send encryption information or a quantum key to the second terminal device 103 via the quantum-optical channel 102.
The user may interact with the second terminal device 103 through the quantum-optical channel 102 using the first terminal device 101 to obtain corresponding encrypted information, etc., and the first terminal device 101 may be a quantum satellite that processes the encrypted information or the quantum key.
The second terminal device 103 may be a terrestrial optical device that processes encrypted information or quantum keys. The second terminal device 103 may perform processing such as analysis on data such as encryption information or quantum keys, and compare the processing result with the result obtained by the first terminal device 101 and perform feedback through the quantum optical path channel 102.
It should be noted that, the method for real-time encoding of quantum key distribution applicable to free space provided in the embodiment of the present invention may be generally performed by the first terminal device 101. Accordingly, the apparatus for real-time encoding of quantum key distribution applicable to free space provided by the embodiment of the present invention may be generally disposed in the first terminal device 101. The method for real-time encoding of quantum key distribution applicable to free space provided by the embodiment of the present invention may also be performed by a second terminal device 103 or a cluster of terminal devices different from the first terminal device 101. Accordingly, the apparatus for real-time encoding of quantum key distribution applicable to free space provided by the embodiment of the present invention may also be provided in a second terminal device 103 or a cluster of terminal devices different from the first terminal device 101.
It should be understood that the number of first terminal devices, quantum optical channels, and second terminal devices in fig. 1 are merely illustrative. There may be any number of first terminal devices, quantum optical channels, and second terminal devices, as desired for implementation.
The method for real-time encoding of quantum key distribution applicable to free space according to the embodiment of the invention will be described in detail below based on the scenario described in fig. 1 by using fig. 2 to 5.
Fig. 2 shows a flow chart of a method of free-space quantum key distribution real-time encoding applied to a receiving end according to an embodiment of the present invention.
As shown in fig. 2, the method for real-time encoding of free space quantum key distribution applied to a receiving end in this embodiment includes operations S210 to S250.
In response to receiving the light quantum stream and the laser signal, the light quantum stream is detected with a plurality of measurement basis vectors, resulting in a quantum original detection signal in operation S210.
According to the embodiment of the invention, the optical quantum stream and the laser signal are both transmitted by a transmitting end through a laser communication channel in free space, and the laser signal comprises a plurality of synchronous coding information and a plurality of modulation base vectors.
According to the embodiment of the invention, the light quantum stream is composed of a plurality of light quantum states, each light quantum state represents a key bit, a transmitting end generates a plurality of random quantum keys, and the plurality of random quantum keys are modulated by using a plurality of modulation basis vectors to obtain a plurality of modulated light quantum states.
According to the embodiment of the invention, the laser communication link, namely the laser communication channel, is established between the satellite-ground station (receiving end) and the satellite (transmitting end) by using the laser signal as a carrier for encrypted information transmission, and the characteristics of high communication capacity, small terminal volume, light weight, interference resistance and good confidentiality of laser signal communication are utilized, so that the efficiency and the safety of quantum key distribution are improved.
According to the embodiment of the invention, the transmitting end transmits the light quantum stream and the laser signal in the free space through the multiplexing laser communication channel, and the light quantum stream and the laser signal can be transmitted at high speed in a time-separated manner or sequentially in a preset sequence in the laser communication channel, so that the light quantum stream carrying quantum key information and the laser signal carrying encryption information are transmitted in a switching manner, and the utilization rate of optical fiber resources is improved.
For example, the predetermined sequence may be set to transmit the optical quantum stream first and then transmit the laser signal, or may be set to switch the transmission of the optical quantum stream carrying the quantum key information and the laser signal carrying the encryption information at high speed with 10s as one transmission time period.
According to the embodiment of the invention, the synchronous coding information can comprise the synchronous coding sequence number and the check code, and the receiving end can process the synchronous precision and stability between the sending end and the receiving end according to the check code after receiving the laser signal sent by the sending end, so that the synchronous light is not required to be additionally adopted for synchronizing the sending end and the receiving end, the processing efficiency of the sending end and the receiving end is improved, and the integration level between the sending end and the receiving end is improved.
According to the embodiment of the invention, the receiving end randomly detects each optical quantum state in the received optical quantum stream by using a plurality of measuring basis vectors, and then performs basis vector comparison by using a plurality of modulating basis vectors in the laser signal to obtain a screening key of the receiving end, namely a quantum original detection signal.
According to an embodiment of the present invention, the plurality of modulation basis vectors at the transmitting end and the plurality of measurement basis vectors at the receiving end are not identical basis vectors.
In operation S220, a plurality of original key information data packets are generated according to the plurality of synchronous code information and the plurality of measurement basis vectors and transmitted to the transmitting end through the laser communication channel.
According to the embodiment of the invention, the transmitting end is used for comparing the base vectors according to a plurality of modulation base vectors of the transmitting end and a plurality of measurement base vectors in a plurality of original key information data packets to obtain base vector comparison key data and base vector comparison result information, processing the base vector comparison key data by using a low-density parity check code to obtain check data, and generating a plurality of intermediate key information data packets according to the check data and the base vector comparison result information, wherein the base vector comparison result information comprises privacy amplification information.
According to the embodiment of the invention, a receiving end acquires a plurality of synchronous coding information from a laser signal, then generates a key information data packet according to a plurality of measuring base vectors, divides the key information data packet into a plurality of data packets, and embeds the synchronous coding information into each data packet to generate an original key information data packet.
According to the embodiment of the invention, the plurality of original key information data packets are generated, so that even if one original key information data packet is lost in the process of transmitting the plurality of original key information data packets, the influence on the extraction and generation of the subsequent keys can be reduced.
In response to receiving the plurality of intermediate key information data packets, verification data is acquired from the plurality of intermediate key information data packets in operation S230.
According to the embodiment of the invention, after processing the received multiple original key information data packets, the sending end generates multiple intermediate key information data packets, and sends the multiple intermediate key information data packets to the receiving end through a laser communication channel.
According to the embodiment of the invention, the verification data can comprise a code screening key obtained by processing the key data by the transmitting end through the low-density parity check code, and can also comprise an error rate calculated by the transmitting end, but is not limited to the information.
According to embodiments of the present invention, the check data may be used to assist the receiving end in error correction and interleaving processes.
According to the embodiment of the invention, each intermediate key information data packet comprises partial check data, and the receiving end acquires all check data from a plurality of intermediate key information data packets so as to use the check data to correct and interweave the quantum key, thereby improving the accuracy and reliability of data transmission and further ensuring the real-time performance and the code rate of quantum key distribution.
In operation S240, a check matrix of the low density parity check code is determined according to the check data, and the check data is subjected to iterative decoding processing by using the check matrix to obtain a verification quantum key.
According to the embodiment of the invention, the verification quantum key can be characterized as an original quantum key sent by a sending end, which is obtained by performing iterative decoding processing on the coding screening key in the verification data by using the check matrix.
According to the embodiment of the invention, the sending end and the receiving end can both utilize the LDPC (Low DENSITY PARITY CHECK ) error correction technology to correct the received check data, so that the interaction of encrypted data is only carried out once between the receiving end and the sending end in the process of transmitting data outside the optical quantum stream, namely, the receiving end sends a plurality of original key information data packets to the sending end, the sending end sends a plurality of intermediate key information data packets obtained after processing to the receiving end, and the communication cost of quantum key distribution is reduced through single interaction, thereby the instantaneity and the efficiency of quantum key distribution are realized.
According to the embodiment of the invention, in the process of performing iterative decoding processing on the check data by using the check matrix, the check data can be iterated for tens of times, so that the calculation amount of a receiving end and the throughput rate of a memory are high, a high-speed memory with the read-write rate of 200MB/s can be used, and a quantum key distribution system with the average error rate of about 2% can only reach the original key processing rate of about 300KB/s at most. For the system of modulation frequency of gigahertz, if higher processing capability of original key is needed, the processing speed can be improved by using parallel computing technology of a field programmable gate array, that is, processing units of multiple LDPC error correction are used to process the encoded key simultaneously, and in the case that processing units of multiple LDPC error correction are used to process the encoded key simultaneously, more resources need to be increased, such as the number of memories needs to be doubled.
In operation S250, privacy amplification processing is performed on the verification quantum key based on the quantum original probe signal and the privacy amplification information, to obtain a target quantum key.
According to the embodiment of the invention, based on the quantum original detection signal and the privacy amplification information, partial key information is obtained from the decoded verification quantum key and the quantum original detection signal for verification and comparison, a verification result is obtained, whether the quantum key is eavesdropped in the transmission process can be determined according to the verification result, meanwhile, the error rate can be calculated again according to the verification result, the quantum key transmission failure can be represented under the condition that the error rate calculated by the receiving end exceeds a preset safety threshold, the next quantum key transmission can be waited, the quantum key transmission success can be represented under the condition that the error rate calculated by the receiving end does not exceed the preset safety threshold, and the target quantum key is obtained by carrying out privacy amplification processing on the verification quantum key.
According to the embodiment of the invention, after the target quantum key is obtained, the key pool management of the system can be performed on the target quantum key.
According to the embodiment of the invention, the privacy of the key can be enhanced by performing privacy amplification processing on the target quantum key so as to further reduce potential leaked information and improve the security of the key, and a specific algorithm such as a hash function can be used in the privacy amplification process.
According to the embodiment of the invention, a receiving end responds to the received optical quantum flow carrying quantum key information and the laser signal carrying encryption information sent by a laser communication channel of a sending end, a plurality of measuring basis vectors in the receiving end are utilized to detect the optical quantum flow to obtain a quantum original detection signal, the receiving end generates a plurality of original key information data packets according to a plurality of measuring basis vectors and a plurality of synchronous coding information in the laser signal, then the plurality of original key information data packets are sent to the sending end through the laser communication channel, the sending end processes the plurality of original key information data packets to generate a plurality of intermediate key information data packets, the sending end sends the plurality of intermediate key information data packets to the receiving end, the receiving end responds to the received plurality of intermediate key information data packets to extract check data, a check matrix of a low-density parity check code is determined according to the check data, the check matrix is utilized to conduct repeated iterative decoding processing on the check data to obtain a verification quantum key, and privacy amplification processing is conducted on the verification quantum key based on the quantum original detection signal and privacy amplification information to obtain a target quantum key. The method realizes high-efficiency real-time extraction of the quantum key distribution in the environment of unreliable channels, improves the code rate of the quantum key through repeated iterative error correction, reduces the influence of the environment of a free space transmission channel on the quantum key distribution, and improves the reliability and stability of the quantum key distribution. Furthermore, by utilizing the high-speed transmission capability and high communication capacity of laser communication and transmitting the light quantum stream and the laser signal through a laser communication channel, the transmission efficiency and the safety of encrypted information are improved, the utilization rate of optical fiber resources is improved, and further, the data are transmitted in a subpacket mode for multiple times, so that in the transmission process of an unreliable channel, even if the situation of data packet loss occurs, the generation and the extraction of other keys are not influenced, the transmission efficiency and the transmission performance of a system are improved, and the quantum key distribution real-time coding in the unreliable channel with unstable free environment and links is realized.
According to the embodiment of the invention, in the process of quantum key distribution, the low-density parity check error correction technology is adopted to carry out error correction check on the screening key by optimizing the quantum key extraction algorithm and the process, so that the interaction times between a receiving end and a transmitting end are reduced, the communication cost is reduced, the interaction safety is improved, and the safety of a system is further enhanced because the quantum key distribution technology has true randomness, indestructibility, communication mode safety and traceability.
According to the embodiment of the application, the quantum key distribution real-time coding method suitable for free space can be widely applied to different transmission channels and communication scenes, and has good expandability and adaptability. The real-time quantum key distribution coding method suitable for free space can provide stable and reliable quantum key distribution service no matter the communication is carried out between satellites and ground stations or between satellites.
According to an embodiment of the present invention, in response to receiving a light quantum stream and a laser signal, the light quantum stream is detected using a plurality of measurement basis vectors, resulting in a quantum original detection signal, comprising:
according to the embodiment of the invention, in response to receiving the light quantum stream and the laser signal, the light quantum state in the light quantum stream is detected by utilizing a plurality of measuring basis vectors, and a quantum original detection signal is obtained.
According to the embodiment of the invention, after receiving the light quantum stream carrying the quantum key information and the laser signal carrying the encryption information, a receiving end randomly acquires a plurality of measuring basis vectors which are consistent with the number of light quantum states in the light quantum stream, and detects the plurality of light quantum states in the light quantum stream one by utilizing the plurality of measuring basis vectors to obtain a first initial quantum detection signal.
According to the embodiment of the invention, each measuring basis vector and each modulation basis vector are subjected to comparison processing, and under the condition that the measuring basis vector and the modulation basis vector are consistent, a first initial quantum detection signal corresponding to the measuring basis vector is determined to be a quantum original detection signal.
According to the embodiment of the invention, a receiving end obtains a plurality of modulation basic vectors used for modulating a quantum key by a sending end from a laser signal, and performs basic vector comparison on a plurality of measurement basic vectors and a plurality of modulation basic vectors to obtain a basic vector comparison result in the receiving end.
According to the embodiment of the invention, the base vector comparison result in the receiving end comprises that the measured base vectors and the modulation base vectors of the bits are inconsistent, and the measured base vectors and the modulation base vectors of the bits are consistent.
According to the embodiment of the invention, according to the basic vector comparison result, a first initial quantum detection signal of a bit with a consistent measurement basic vector and a modulation basic vector is reserved as a quantum original detection signal.
According to the embodiment of the invention, as the light quantum state in the light quantum stream is detected by utilizing a plurality of measuring basis vectors in response to receiving the light quantum stream and the laser signal, the quantum original detection signal is obtained, each measuring basis vector and each modulating basis vector are compared, under the condition that the measuring basis vector and the modulating basis vector are consistent, the first initial quantum detection signal corresponding to the measuring basis vector is determined to be the quantum original detection signal, the light quantum stream is detected by utilizing the random measuring basis vector at the receiving end, then the basis vector comparison is carried out according to the plurality of measuring basis vectors and the plurality of modulating basis vectors, and the quantum original detection signal of the receiving end is accurately obtained according to the result of the basis vector comparison.
Fig. 3 shows a flow chart of a method of transmitting a plurality of original key information data packets according to an embodiment of the present invention.
As shown in FIG. 3, the method for transmitting a plurality of original key information data packets in this embodiment includes operations S310-S350.
According to an embodiment of the present invention, the synchronization coding information includes a synchronization coding sequence number and a check code.
According to an embodiment of the present invention, generating a plurality of original key information data packets according to a plurality of synchronous code information and a plurality of measurement basis vectors and transmitting the plurality of original key information data packets to a transmitting end through a laser communication channel, includes:
In operation S310, a plurality of measurement basis vectors are subjected to a packing process to obtain a first key information packet.
According to the embodiment of the invention, a receiving end packages a plurality of measuring basis vectors for demodulating a plurality of light quantum states to obtain a first key information data packet containing all measuring basis vector information.
In operation S320, the first key information packet is packetized to obtain a plurality of intermediate original key information packets with sequential numbers.
According to the embodiment of the invention, the first key information data packet can be subjected to sequential packetization according to the capacity of the data packet, and the data packet can also be subjected to random sequential packetization to obtain a plurality of intermediate original key information data packets with sequential numbers.
For example, the predetermined capacity of each packet may be set to 100MB in advance, the first key information packet may be divided into a plurality of intermediate original key information packets each having a capacity of 100MB with a sequence number according to the predetermined capacity, and the first key information packet may be divided into 5 intermediate original key information packets having a capacity that is not uniform.
According to an embodiment of the present invention, each intermediate original key information packet is provided with a sequence number for packetizing according to the packetizing sequence.
In operation S330, the plurality of synchronization code sequence numbers and the sequence numbers of the plurality of intermediate original key information data packets are matched to obtain a matching result.
According to the embodiment of the invention, the matching is performed according to the sequence number and the synchronous coding sequence number of the intermediate original key information data packets, so as to ensure that each intermediate original key information data packet is matched with one synchronous coding sequence number.
For example, the sequence number of the first intermediate original key information packet is 1, the synchronous code information with synchronous code number 1 is determined to be matched with the first intermediate original key information packet from the plurality of synchronous code information, the sequence number of the second intermediate original key information packet is 2, and the synchronous code information with synchronous code number 2 is determined to be matched with the second intermediate original key information packet from the plurality of synchronous code information.
In operation S340, based on the matching result, the synchronization coding information corresponding to the sequence number is embedded into the intermediate original key information packet, thereby obtaining a plurality of original key information packets with the synchronization coding information.
According to the embodiment of the invention, the synchronous coding information corresponding to the sequence number is embedded into the middle original key information data packet, so that after the data packet is transmitted to the transmitting end, the transmitting end can judge whether all the data packets are received according to the synchronous coding sequence number in each original key information data packet.
In operation S350, a plurality of original key information packets with synchronous code information are transmitted to the transmitting end.
According to the embodiment of the invention, the receiving end sends a plurality of original key information data packets with synchronous coding information to the sending end through the laser communication channels in the free space, so that the sending end can conveniently carry out subsequent operations of base vector comparison and equivalent sub-key extraction by calculating the bit error rate after receiving the plurality of original key information data packets with synchronous coding information.
According to the embodiment of the invention, the first key information data packet is obtained by packing a plurality of measurement base vectors, the first key information data packet is subjected to packing processing to obtain a plurality of intermediate original key information data packets with sequential numbers, the synchronous coding sequence numbers are matched with the sequential numbers of the plurality of intermediate original key information data packets, synchronous coding information corresponding to the sequential numbers is embedded into the intermediate original key information data packets to obtain a plurality of original key information data packets with synchronous coding information, the plurality of original key information data packets with synchronous coding information are sent to a sending end through a laser communication channel in a free space, the encrypted data information is packetized, the plurality of original key information data packets can be sent to the sending end at the same time, the pressure of sending encrypted data of a receiving end and the pressure of receiving end are reduced, the processing efficiency of the sending end and the receiving end is improved, the time cost spent for quantum key extraction is reduced, the efficiency of quantum key distribution extraction is improved, the sending end and the receiving end can check whether the received data is complete or not influence on subsequent key extraction and generation even if the packets are lost in the process of encrypted data transmission.
Fig. 4 shows a flow chart of a method of acquiring verification data according to an embodiment of the invention.
As shown in fig. 4, the method for transmitting a plurality of original key information data packets in this embodiment includes operations S410 to S440.
According to an embodiment of the present invention, in response to receiving a plurality of intermediate key information data packets, obtaining verification data from the plurality of intermediate key information data packets includes:
in response to receiving the plurality of intermediate key information data packets, a synchronization coding sequence number corresponding to each intermediate key information data packet is acquired in operation S410.
According to the embodiment of the invention, the sending end generates a plurality of intermediate key information data packets after processing the received plurality of original key information data packets, the plurality of intermediate key information data packets are sent to the receiving end, and the receiving end acquires the synchronous coding sequence number from each intermediate key information data packet.
According to the embodiment of the invention, the intermediate key information data packet may include a base vector comparison result obtained by the transmitting end after base vector comparison, an accompanying type, a security factor, privacy amplification information and check data encoded by the encoding matrix of the low-density parity check code, but is not limited to the above data information.
In operation S420, the intermediate key information data packets are filled into the storage space according to the sync coding sequence number corresponding to each intermediate key information data packet.
According to an embodiment of the invention, the receiving end comprises a plurality of storage spaces with space numbers.
According to the embodiment of the invention, the receiving end can set a plurality of storage spaces with space numbers according to the total capacity and the total number of the intermediate key information data packets to be sent by the sending end.
According to the embodiment of the invention, the laser communication channel is affected by free space environment or noise, so that data loss can possibly exist in the process of data packet transmission, and further, in order to improve reliability, a plurality of intermediate key information data packets can be continuously transmitted to a receiving end repeatedly according to a preset frequency for a plurality of times under the condition that the transmitting end does not perform the next transmission task of the optical quantum stream carrying the quantum key by utilizing the bandwidth of the quantum optical channel according to the characteristic that the transmission quantity of the encrypted data is required to be large (about 30M/s) of the bandwidth of the quantum optical channel (the bandwidth of the quantum optical channel is more than 155M/s transmission rate).
According to the embodiment of the invention, the synchronous code sequence number corresponding to each intermediate key information data packet is matched with the space number of each storage space, and the intermediate key information data packet is stored in the storage space under the condition that the matching is consistent.
For example, a total of 5 intermediate key information packets, the sync code number of the 2 nd intermediate key information packet is confirmed to be 3, and the 2 nd intermediate key information packet is stored in the storage space with the space number of 3.
In operation S430, the synchronization code number corresponding to the intermediate key packet stored in the storage space is checked based on the space number of the storage space, to obtain a check result.
According to the embodiment of the invention, after the received intermediate key information data packets are stored in the storage space, the synchronous coding sequence numbers corresponding to the intermediate key data packets stored in the storage space are checked, and whether the space number of each storage space is consistent with the synchronous coding sequence number of the stored intermediate key information data packet is checked.
According to the embodiment of the invention, under the condition that the space number of each storage space is consistent with the synchronous coding sequence number of the stored intermediate key information data packet, the verification result represents that the verification passes, and under the condition that the space number of each storage space is inconsistent with the synchronous coding sequence number of the stored intermediate key information data packet, the verification result represents that the verification does not pass.
In operation S440, in case that the verification result indicates that the verification passes and the number of the intermediate key information data packets stored in the storage space satisfies the first preset condition, verification data is acquired from the plurality of intermediate key information data packets.
According to the embodiment of the invention, the sending end can send the total number of the intermediate key information data packets to the receiving end while sending a plurality of intermediate key information data packets to the receiving end, and the first preset condition can be characterized as the total number of the intermediate key information data packets of the receiving end.
According to the embodiment of the invention, under the condition that the verification result represents that verification passes, whether the intermediate key information data packet is stored in each storage space is checked.
According to the embodiment of the invention, in the case that the intermediate key information data packets are stored in each storage space, the verification data is acquired from a plurality of intermediate key information data packets.
According to the embodiment of the invention, under the condition that the intermediate key information data packet stored in each storage space does not meet the first preset condition, a plurality of intermediate key information data packets are continuously received until the intermediate key information data packets stored in the storage space meet the first preset condition.
According to the embodiment of the invention, under the condition that the intermediate key information data packets are not stored in the storage space, the transmitting end continuously transmits the intermediate key information data packets, the receiving end continuously refreshes the storage space according to the filling grid mode until each storage space contains the intermediate key information data packets, and in the process that the receiving end continuously receives the intermediate key information data packets by taking the data frames as units, the data frames can confirm successful reception as long as the data frames are correct once, namely, the first preset condition is met.
According to the embodiment of the invention, the sending end can send a plurality of groups of intermediate key information data packets to the receiving end, one group can comprise a plurality of intermediate key information data packets, and under the condition that the sending end needs to send the next group of intermediate key information data packets to the receiving end, the receiving end can check whether the intermediate key information data packets in the storage space meet the first preset condition in advance, and under the condition that the first preset condition is still not met, all the intermediate key information data packets in all the storage space are discarded, and the transmission of the next group of intermediate key information data packets is continued.
According to the embodiment of the invention, before the sending end needs to send the optical quantum stream carrying the new quantum key to the receiving end, the receiving end can check in advance whether the intermediate key information data packet in the storage space meets the first preset condition, and discard all the intermediate key information data packets in all the storage spaces under the condition that the first preset condition is still not met, so as to continue the transmission of the optical quantum stream carrying the new quantum key.
According to the embodiment of the invention, the receiving end responds to the received multiple intermediate key information data packets to obtain the synchronous coding sequence number corresponding to each intermediate key information data packet, the intermediate key information data packets are filled into the storage space according to the synchronous coding sequence number corresponding to each intermediate key information data packet, the synchronous coding sequence number corresponding to the intermediate key information data packet stored in the storage space is verified based on the space number of the storage space to obtain a verification result, verification data are obtained from the multiple intermediate key information data packets when the verification result represents that the verification is passed and the number of the intermediate key information data packets stored in the storage space meets the first preset condition, the multiple intermediate key information data packets are continuously received when the intermediate key information data packets stored in each storage space do not meet the first preset condition, retransmission and discarding of the multiple intermediate key information data packets are realized until the intermediate key information data packets stored in the storage space are continuously received, the intermediate key information data packets stored in the storage space only need to meet the first preset condition once, and the free transmission of the free laser can be prevented.
According to the embodiment of the invention, a check matrix is determined according to check data, and the check data is subjected to iterative decoding processing by using the check matrix of the low-density parity check code to obtain a verification quantum key, which comprises the following steps:
According to the embodiment of the invention, after receiving the check data, the receiving end can store the check data In an on-chip FIFO (First In, first Out, data structure or buffer management mode) of the receiving end, and under the condition that decoding error correction is required, the receiving end can directly call the check data from the on-chip FIFO.
According to the embodiment of the invention, before LDPC error correction is carried out on the check data, the receiving end can carry out de-interleaving treatment on the check data so as to obtain a more accurate verification quantum key, improve the safety and reliability of communication and reduce the error rate.
According to an embodiment of the invention, the encoding matrix and the encoding key are obtained from the verification data.
According to the embodiment of the invention, the coding key can be characterized as a key obtained by a transmitting end by coding the base vector comparison key data by using a coding matrix according to the error correction of the low-density parity check code.
According to an embodiment of the invention, the check matrix is determined from the encoding matrix.
According to an embodiment of the present invention, the transpose multiplication of the check matrix and the encoding matrix is equal to zero, so that the check matrix of the encoding key for decoding error correction is determined from the encoding matrix.
According to the embodiment of the invention, according to the state of each quantum bit in the coding key, the non-zero state in the check matrix is replaced by the probability likelihood ratio of the key, and the variable matrix is constructed.
According to the embodiment of the invention, the key probability likelihood ratio is obtained by carrying out log likelihood ratio calculation on the prior probability of the key.
According to the embodiment of the invention, according to the preset 0-state key prior probability and 1-state key prior probability, the corresponding key probability likelihood ratios are calculated respectively by using the log likelihood ratios, wherein when the probability that the quantum key is in 0 state is larger, the 0-state key probability likelihood ratio is positive, the 1-state key probability likelihood ratio is negative, and when the probability that the quantum key is in 1 state is larger, the 0-state key probability likelihood ratio is negative, and the 1-state key probability likelihood ratio is positive.
According to the embodiment of the invention, a receiving end determines a key probability likelihood ratio corresponding to the state of each quantum bit according to the state of each quantum bit in the received coding key, replaces an element 1 in the check matrix with an element value of the 1-state key probability likelihood ratio, and the element 0 in the check matrix is unchanged to obtain an intermediate matrix.
According to the embodiment of the invention, the variable matrix is obtained by adding the corresponding positive and negative value to each element in the intermediate matrix according to the positive and negative of the key probability likelihood ratio corresponding to the state of each quantum bit.
For example, when the probability that the quantum key is in the 0 state is larger, the 0-state key probability likelihood ratio is positive, the 1-state key probability likelihood ratio is negative, the first element in the encoded key is 1, the elements in the first column in the intermediate matrix are all negative, the second element in the encoded key is 0, and the elements in the second column in the intermediate matrix are all positive.
According to the embodiment of the invention, a first calculation operation is performed on the variable matrix and the key probability likelihood ratio, so as to obtain the state probability corresponding to the coding key.
According to the embodiment of the invention, the variable matrix is processed according to the preset rule to obtain the probability matrix, and the preset rule is characterized in that the non-zero elements in the variable matrix are subjected to logarithmic calculation. For example, the variable matrix is 43, Calculating the first element in the first row to obtain the first element in the first row of the probability matrix by utilizing the second element and the fourth element to carry out logarithmic calculation, wherein the third element in the first row of the probability matrix is consistent with the third element in the first row of the variable matrix, and is 0 element, and the other rows in the matrix are calculated as above to obtain the final probability matrix.
According to the embodiment of the invention, a first calculation operation is performed on the probability matrix to obtain the state probability corresponding to the coding key, the first calculation operation is to sum each column in the probability matrix, and then the state probability with positive and negative corresponding to the coding key is obtained by adding the key probability likelihood ratio corresponding to the state of each qubit in the coding matrix to the sum value of each column.
According to the embodiment of the invention, a state judgment operation is carried out on each quantum bit in the coding key according to the key probability likelihood ratio, so that an intermediate coding key is obtained.
According to the embodiment of the invention, the intermediate coding key is obtained according to the state probability with positive and negative corresponding to the coding key and the 0 state or 1 state corresponding to the positive and negative corresponding to the key probability likelihood ratio, for example, the 0 state key probability likelihood ratio is positive, the 1 state key probability likelihood ratio is negative, the first element with positive and negative corresponding to the coding key is determined to be 1, the first element with positive corresponding to the coding key is determined to be 0.
According to the embodiment of the invention, the verification operation is executed on the intermediate coding key by using the check matrix, and under the condition that the verification result does not meet the second preset condition, the variable matrix is subjected to iterative updating to obtain the updated variable matrix, and the first calculation operation, the state judgment operation and the verification operation are executed again aiming at the updated variable matrix until the verification result meets the second preset condition.
According to the embodiment of the invention, the second preset condition characterization is calculated by using the check matrix and the intermediate coding key, and the obtained matrix result is a zero vector.
According to the embodiment of the invention, the check matrix and the intermediate coding key are utilized for calculation, under the condition that the obtained matrix result is not zero vector, the variable matrix and the probability matrix are subjected to iterative updating, the updated variable matrix and the updated probability matrix are obtained, and subsequent operations are sequentially carried out until the verification result meets a second preset condition.
According to the embodiment of the invention, the update times threshold can be set for the iterative update times, and if the update times threshold is exceeded, the verification result still cannot meet the second preset condition, and then the decoding fails.
According to the embodiment of the invention, the intermediate encoding key is determined to be the verification quantum key under the condition that the verification result meets the second preset condition.
According to the embodiment of the invention, the receiving end performs sampling inspection and monitoring calculation according to the verification quantum key and the first quantum key to obtain the receiving error rate of the receiving end, the error rate threshold value can be set, decoding failure is confirmed under the condition that the receiving error rate exceeds the error rate threshold value, and otherwise decoding is successful.
According to the embodiment of the invention, under the condition that decoding is successful, decoding results can be stored in the on-chip cache FIFO to provide key data for subsequent privacy amplification.
According to the embodiment of the invention, the encoding matrix and the encoding key are obtained from the check data, the check matrix is determined according to the encoding matrix, the non-zero state in the check matrix is replaced by the key probability likelihood ratio according to the state of each quantum bit in the encoding key, the variable matrix is constructed, the first calculation operation is carried out on the variable matrix and the key probability likelihood ratio, the state probability corresponding to the encoding key is obtained, the state judgment operation is carried out on each quantum bit in the encoding key according to the key probability, the intermediate encoding key is obtained, the verification operation is carried out on the intermediate encoding key by the check matrix, the variable matrix is subjected to iterative update under the condition that the verification result does not meet the second preset condition, the first calculation operation, the state judgment operation and the verification operation are carried out again on the updated variable matrix until the verification result meets the second preset condition, the intermediate encoding key is determined to be the verification quantum key under the condition that the verification result meets the second preset condition, the decoding and error correction processing of the encoded key received by the receiving terminal are realized, the accurate screening key is obtained, the iteration times and the code rate are set, the success of the receiving terminal is judged, and the reliability of the error correction system is further improved, and the reliability of the real-time safety and the receiving system is further realized.
According to an embodiment of the present invention, based on a quantum original detection signal and privacy amplification information, privacy amplification processing is performed on a verification quantum key to obtain a target quantum key, including:
according to the embodiment of the invention, the privacy amplification information is obtained from the base vector comparison result information.
According to an embodiment of the present invention, a predetermined privacy amplification length may be included in the privacy amplification information.
According to the embodiment of the invention, the verification quantum key and the quantum original detection signal are compared to obtain a comparison result. According to the embodiment of the invention, under the condition that the comparison result is characterized in that the comparison of the verification quantum key and the quantum original detection signal is consistent, the verification quantum key is subjected to privacy amplification processing by adopting a hash function according to the privacy amplification information, so that the target quantum key is obtained.
According to the embodiment of the invention, under the condition that the comparison result is characterized as that the comparison of the verification quantum key and the quantum original detection signal is inconsistent, the quantum original detection signal is discarded and the comparison result is sent to the sending end.
According to the embodiment of the invention, the verification quantum key can comprise a verification code, the quantum original detection signal can comprise a measurement code, the verification code and the measurement code are compared, if the verification code is consistent with the measurement code, the transmission of the quantum key is not eavesdropped, the quantum key except the verification code in the verification quantum key is taken as a target quantum key, key pool management is carried out, if the verification code is inconsistent with the measurement code, the transmission of the quantum key is eavesdropped, the receiving end can discard the verification quantum key and the quantum original detection signal, and the sending end can send a key extraction result so as to adjust the transmission of the quantum key, and the safety is improved.
According to the embodiment of the invention, the privacy amplification information is obtained from the basic vector comparison result information, the verification quantum key is compared with the quantum original detection signal, the privacy amplification processing is carried out on the verification quantum key according to the privacy amplification information under the condition that the verification quantum key is consistent with the quantum original detection signal, the target quantum key is obtained, the quantum original detection signal is discarded and the comparison result is sent to the sending end under the condition that the comparison result is characterized in that the verification quantum key is inconsistent with the quantum original detection signal, so that the extraction of the target quantum key from the screening quantum key of the receiving end is realized, and the code rate and the processing efficiency of the quantum key are further improved.
Fig. 5 shows a flow chart of a method for real-time encoding of a free-space applicable quantum key distribution applied to a sender according to an embodiment of the present invention.
As shown in fig. 5, the method for transmitting a plurality of original key information data packets in this embodiment includes operations S510 to S540.
In operation S510, an optical quantum stream and a laser signal are transmitted to a receiving end through a laser communication channel in a free space.
According to an embodiment of the present invention, a plurality of synchronous encoded information and a plurality of modulation basis vectors are included in a laser signal.
According to the embodiment of the invention, a transmitting end randomly generates a series of original quantum keys, and the original quantum keys are modulated by utilizing a plurality of modulation basis vectors to obtain a plurality of optical quantum states, and the plurality of optical quantum states form an optical quantum stream.
According to the embodiment of the invention, the sending end alternately switches and transmits the light quantum stream and the laser signal through the quantum light path channel, so that the utilization rate of the optical fiber resource is improved.
According to the embodiment of the invention, the quantum laser at the transmitting end can reach the GHz modulation frequency, and the high-speed random number acquired from the random number generator is used for generating the modulated light quantum state and also needs to be stored locally. Random number storage requires large throughput and storage depth requirements. Each light quantum state needs 8bit random number modulation, and according to GHz modulation frequency calculation, the speed of data processing during modulation needs 1GB/s, so that the data processing can be realized in an ASIC (Application-SPECIFIC INTEGRATED Circuit), and the serial data can be parallelized by using an FPGA chip and matched with a Serdes (seriizer/Deserializer) technology, so that the time frequency is reduced. Wherein 4 bits of the 8 bits are required to be temporarily stored and are not released until the step of base vector alignment is completed, so that a storage rate of at least 500MB/s is required. The method comprises the steps of carrying out optical quantum state downloading and original key receiving from the storage to the base vector comparison, namely carrying out round-trip time of data, calculating according to a transmission distance of a high orbit satellite by 3 kilokilometers, wherein the round-trip photon transmission time only needs about 200ms, and further comprises laser communication data processing time, such as interleaving and de-interleaving, scrambling, RS encoding and decoding and the like, at least random numbers with 300ms duration, namely 150MB data, are needed to be stored.
In operation S520, in response to receiving the plurality of original key information data packets, the key data and the base vector comparison result information are obtained according to the plurality of modulation base vectors of the transmitting end and the plurality of measurement base vectors in the plurality of original key information data packets.
According to an embodiment of the present invention, a plurality of original key information data packets are transmitted over a laser communication channel.
According to the embodiment of the invention, a plurality of original key information data packets with synchronous coding information are received by a sending end, a plurality of cache spaces can be also reserved in the sending end, each cache space can be provided with a space number, the synchronous coding sequence number in each original key information data packet and the space number of the cache space are matched and stored one by one, the original key information data packets in the cache space of the sending end can be judged, whether the synchronous coding sequence number is consistent with the space number is judged, and whether each cache space stores the original key information data packet or not is convenient for judging whether the data packets are all received and carrying out subsequent operations such as continuous reception and the like.
According to the embodiment of the invention, the transmitting end performs base vector comparison according to the modulation base vector and a plurality of received measurement base vectors from the receiving end to obtain the screening key of the transmitting end, namely, the base vector comparison key data, and the error rate of the receiving end can be calculated by using a sampling detection method.
In operation S530, the base vector comparison key data is processed using the low density parity check code to obtain check data, and a plurality of intermediate key information data packets are generated according to the check data and the base vector comparison result information.
According to the embodiment of the invention, before encoding the base vector comparison key data by using the LDPC encoding matrix, the transmitting end can firstly carry out interleaving treatment on the base vector comparison key data so as to improve the transmission safety and reliability.
According to the embodiment of the invention, the transmitting end selects the LDPC coding matrix to code the key data according to the bit error rate obtained by the calculation of the satellite load, and the coding key is obtained.
According to an embodiment of the present invention, the check data is generated according to the syndrome, the security factor, the encoding key, and the encoding matrix, but is not limited to the above information.
According to the embodiment of the invention, the verification data and the base vector comparison result information are subjected to the packetizing operation to obtain a plurality of intermediate key information data packets, and synchronous coding information is embedded into each intermediate key information data packet according to the sequence.
In operation S540, a plurality of intermediate key information data packets are transmitted to the receiving end through the laser communication channel.
According to an embodiment of the present invention, a plurality of intermediate key information data packets are transmitted to a receiving end through a laser communication channel.
According to the embodiment of the invention, the laser communication channel in the free space is used for sending the optical quantum stream and the laser signal to the receiving end, the receiving end is used for responding to the received data packets of the original key information, the key data and the base vector comparison result information are obtained according to the modulated base vectors of the sending end and the measured base vectors of the original key information data packets, the base vector comparison key data are processed by using the low-density parity check codes, the check data are obtained, the data packets of the intermediate key information are generated according to the check data and the base vector comparison result information, the data packets of the intermediate key information are sent to the receiving end through the laser communication channel, the high-efficiency real-time extraction of quantum key distribution is realized, the key data are coded according to the error rate selection coding matrix, the transmission safety of the encrypted information is improved, the free space laser communication channel is used, the high-speed transmission capacity and the high-communication capacity of laser communication are combined, the utilization rate of optical fiber resources is improved, the quantum key distribution real-time code formation and Gao Cheng code rate in the environment of free space and the unstable link are realized, and the quantum key distribution real-time code formation under the environment is realized under the unreliable transmission channel.
Fig. 6 shows a block diagram of an apparatus for real-time encoding of quantum key distribution applicable to free space applied to a receiving end according to an embodiment of the present invention.
As shown in fig. 6, the apparatus for real-time encoding of quantum key distribution applicable to free space at the receiving end of this embodiment includes a detection module 610, a generation module 620, an acquisition module 630, a decoding module 640, and a privacy amplification module 650.
The detection module 610 is configured to detect the optical quantum stream by using a plurality of measurement basis vectors in response to receiving the optical quantum stream and the laser signal, so as to obtain a quantum original detection signal, where the optical quantum stream and the laser signal are both obtained by the transmitting end through transmission of a laser communication channel in free space, and the laser signal includes a plurality of synchronous coding information and a plurality of modulation basis vectors. The detection module 610 may be configured to perform the operation S210 described above, and will not be described herein.
The generating module 620 is configured to generate a plurality of original key information data packets according to the plurality of synchronous encoded information and the plurality of measurement base vectors, and send the plurality of original key information data packets to the sending end through the laser communication channel, where the sending end is configured to obtain base vector comparison key data and base vector comparison result information according to a plurality of modulation base vectors of the sending end and a plurality of measurement base vectors in the plurality of original key information data packets, process the base vector comparison key data by using a low-density parity check code to obtain check data, and generate a plurality of intermediate key information data packets according to the check data and the base vector comparison result information, where the base vector comparison result information includes privacy amplification information. The generating module 620 may be configured to perform the operation S220 described above, which is not described herein.
The obtaining module 630 is configured to obtain verification data from the plurality of intermediate key information data packets in response to receiving the plurality of intermediate key information data packets. The obtaining module 630 may be configured to perform the operation S230 described above, which is not described herein.
And the decoding module 640 is configured to determine a check matrix of the low-density parity check code according to the check data, and perform iterative decoding processing on the check data by using the check matrix to obtain the verification quantum key. The decoding module 640 may be configured to perform the operation S240 described above, which is not described herein.
The privacy amplification module 650 is configured to perform privacy amplification processing on the verification quantum key based on the quantum original detection signal and the privacy amplification information, so as to obtain a target quantum key. The privacy amplification module 650 may be used to perform the operation S250 described above, and will not be described herein.
The detection module 610 includes a first detection sub-module and a first comparison sub-module, according to an embodiment of the present invention.
And the first detection submodule is used for responding to the received light quantum stream and the laser signal, and detecting the light quantum state in the light quantum stream by utilizing a plurality of measuring basis vectors to obtain a first initial quantum detection signal.
And the first comparison sub-module is used for comparing each measuring base vector with each modulation base vector, and determining a first initial quantum detection signal corresponding to the measuring base vector as a quantum original detection signal under the condition that the measuring base vector is consistent with the modulation base vector.
The generating module 620 includes a first packet-forming sub-module, a first packet-dividing sub-module, a first matching sub-module, a first embedding sub-module, and a first transmitting sub-module according to an embodiment of the present invention.
And the first packing sub-module is used for packing the plurality of measurement basic vectors to obtain a first key information data packet.
And the first packet sub-module is used for carrying out the packetization processing on the first key information data packet to obtain a plurality of intermediate original key information data packets with sequential numbers.
And the first matching sub-module is used for matching the synchronous coding sequence numbers with the sequence numbers of the intermediate original key information data packets to obtain a matching result.
And the first embedding sub-module is used for embedding the synchronous coding information corresponding to the sequence numbers into the middle original key information data packet based on the matching result to obtain a plurality of original key information data packets with synchronous coding information.
And the first sending sub-module is used for sending a plurality of original key information data packets with synchronous coding information to the sending end.
The acquisition module 630 includes a first acquisition sub-module, a first fill sub-module, a first verification sub-module, and a second acquisition sub-module, according to an embodiment of the present invention.
And the first acquisition sub-module is used for responding to the received multiple intermediate key information data packets and acquiring the synchronous coding sequence number corresponding to each intermediate key information data packet.
And the first filling submodule is used for filling the intermediate key information data packets into the storage space according to the synchronous coding sequence numbers corresponding to each intermediate key information data packet, wherein the receiving end comprises a plurality of storage spaces with space numbers.
And the first verification sub-module is used for verifying the synchronous code sequence number corresponding to the intermediate key data packet stored in the storage space based on the space number of the storage space to obtain a verification result.
The second obtaining sub-module is used for obtaining the verification data from the plurality of intermediate key information data packets under the condition that the verification result represents that the verification passes and the number of the intermediate key information data packets stored in the storage space meets the first preset condition.
The acquisition module 630 further includes a first continuous reception sub-module, according to an embodiment of the present invention.
And the first continuous receiving sub-module is used for continuously receiving the plurality of intermediate key information data packets under the condition that the intermediate key information data packets stored in each storage space do not meet the first preset condition until the intermediate key information data packets stored in the storage space meet the first preset condition.
The decoding module 640 includes a third acquisition sub-module, a first determination sub-module, a first replacement sub-module, a first calculation sub-module, a first determination sub-module, a first verification sub-module, and a second determination sub-module, according to an embodiment of the present invention.
And the third acquisition sub-module is used for acquiring the coding matrix and the coding key from the check data.
And the first determining submodule is used for determining a check matrix of the low-density parity check code according to the coding matrix.
The first replacing sub-module is used for replacing the non-zero state in the check matrix by using the key probability likelihood ratio according to the state of each quantum bit in the coded key to construct a variable matrix, wherein the key probability likelihood ratio is obtained by carrying out log likelihood ratio calculation on the prior probability of the key.
And the first computing sub-module is used for executing a first computing operation on the variable matrix and the key probability likelihood ratio to obtain the state probability corresponding to the coding key.
And the first judging submodule is used for executing state judging operation on each quantum bit in the coding key according to the key probability likelihood ratio to obtain an intermediate coding key.
The first verification sub-module is used for executing verification operation on the intermediate coding key by using the verification matrix, and carrying out iterative updating on the variable matrix under the condition that the verification result does not meet a second preset condition to obtain an updated variable matrix, and re-executing first calculation operation, state judgment operation and verification operation aiming at the updated variable matrix until the verification result meets the second preset condition, wherein the second preset condition characterizes that the verification result is calculated by using the verification matrix and the intermediate coding key, and the obtained matrix result is a zero vector.
And the second determining submodule is used for determining the intermediate coding key as the verification quantum key under the condition that the verification result meets a second preset condition.
The privacy amplification module 650 includes a fourth acquisition sub-module, a second comparison sub-module, a first privacy amplification sub-module, and a first feedback sub-module, according to an embodiment of the present invention.
And the fourth acquisition sub-module is used for acquiring privacy amplification information from the base vector comparison result information.
And the second comparison sub-module is used for comparing the verification quantum key with the quantum original detection signal to obtain a comparison result.
The first privacy amplification submodule is used for carrying out privacy amplification processing on the verification quantum key according to the privacy amplification information under the condition that the comparison result is characterized in that the verification quantum key is identical to the quantum original detection signal, and the target quantum key is obtained.
The first feedback sub-module is used for discarding the quantum original detection signal and sending the comparison result to the sending end under the condition that the comparison result is characterized as that the comparison of the verification quantum key and the quantum original detection signal is inconsistent.
Any of the detection module 610, the generation module 620, the acquisition module 630, the decoding module 640, and the privacy amplification module 650 may be combined in one module or any of the modules may be split into multiple modules according to an embodiment of the present invention. Or at least some of the functionality of one or more of the modules may be combined with, and implemented in, at least some of the functionality of other modules. At least one of the detection module 610, the generation module 620, the acquisition module 630, the decoding module 640, and the privacy amplification module 650 may be implemented, at least in part, as hardware circuitry, such as a Field Programmable Gate Array (FPGA), a Programmable Logic Array (PLA), a system-on-chip, a system-on-a-substrate, a system-on-a-package, an Application Specific Integrated Circuit (ASIC), or as hardware or firmware in any other reasonable manner of integrating or packaging the circuitry, or as any one of or a suitable combination of three of software, hardware, and firmware. Or at least one of the detection module 610, the generation module 620, the acquisition module 630, the decoding module 640 and the privacy amplification module 650 may be at least partially implemented as a computer program module, which when executed, may perform the corresponding functions.
Fig. 7 shows a block diagram of an apparatus for real-time encoding of quantum key distribution applicable to free space applied to a transmitting end according to an embodiment of the present invention.
As shown in fig. 7, the apparatus for real-time encoding of quantum key distribution applicable to free space applied to a transmitting end of this embodiment includes a first transmitting module 710, an obtaining module 720, a processing module 730, and a second transmitting module 740.
The first transmitting module 710 is configured to transmit, to a receiving end, an optical quantum stream and a laser signal through a laser communication channel in free space, where the laser signal includes a plurality of synchronous encoded information and a plurality of modulation basis vectors. The first sending module 710 may be configured to perform the operation S510 described above, which is not described herein.
The obtaining module 720 is configured to obtain base vector comparison key data and base vector comparison result information according to the plurality of modulation base vectors of the transmitting end and the plurality of measurement base vectors in the plurality of original key information data packets in response to receiving the plurality of original key information data packets, where the plurality of original key information data packets are transmitted through the laser communication channel, and the base vector comparison result information includes privacy amplification information. The obtaining module 720 may be configured to perform the operation S520 described above, which is not described herein.
And the processing module 730 is configured to process the base vector comparison key data by using the low density parity check code to obtain check data, and generate a plurality of intermediate key information data packets according to the check data and the base vector comparison result information. The processing module 730 may be configured to perform the operation S530 described above, which is not described herein.
The second sending module 740 is configured to send a plurality of intermediate key information data packets to the receiving end through a laser communication channel. The second transmitting module 740 may be configured to perform the operation S540 described above, which is not described herein.
Any of the first transmitting module 710, the obtaining module 720, the processing module 730, and the second transmitting module 740 may be combined in one module to be implemented, or any of the modules may be split into a plurality of modules according to an embodiment of the present invention. Or at least some of the functionality of one or more of the modules may be combined with, and implemented in, at least some of the functionality of other modules. According to an embodiment of the present invention, at least one of the first transmitting module 710, the obtaining module 720, the processing module 730, and the second transmitting module 740 may be implemented at least partially as hardware circuitry, such as a Field Programmable Gate Array (FPGA), a Programmable Logic Array (PLA), a system on a chip, a system on a substrate, a system on a package, an Application Specific Integrated Circuit (ASIC), or may be implemented in hardware or firmware in any other reasonable way of integrating or packaging the circuits, or in any one of or a suitable combination of three of software, hardware, and firmware. Or at least one of the first transmitting module 710, the obtaining module 720, the processing module 730 and the second transmitting module 740 may be at least partially implemented as a computer program module, which may perform the corresponding functions when being executed.
Fig. 8 shows a block diagram of an electronic device adapted for a method of free-space quantum key distribution real-time encoding according to an embodiment of the invention.
As shown in fig. 8, the electronic device according to the embodiment of the present invention includes a processor 801 that can perform various appropriate actions and processes according to a program stored in a Read Only Memory (ROM) 802 or a program loaded from a storage section 808 into a Random Access Memory (RAM) 803. The processor 801 may include, for example, a general purpose microprocessor (e.g., a CPU), an instruction set processor and/or an associated chipset and/or a special purpose microprocessor (e.g., an Application Specific Integrated Circuit (ASIC)), or the like. The processor 801 may also include on-board memory for caching purposes. The processor 801 may comprise a single processing unit or multiple processing units for performing the different actions of the method flows according to embodiments of the invention.
In the RAM 803, various programs and data required for the operation of the electronic device are stored. The processor 801, the ROM 802, and the RAM 803 are connected to each other by a bus 804. The processor 801 performs various operations of the method flow according to the embodiment of the present invention by executing programs in the ROM 802 and/or the RAM 803. Note that the program may be stored in one or more memories other than the ROM 802 and the RAM 803. The processor 801 may also perform various operations of the method flow according to embodiments of the present invention by executing programs stored in the one or more memories.
According to an embodiment of the invention, the electronic device may further comprise an input/output (I/O) interface 805, the input/output (I/O) interface 805 also being connected to the bus 804. The electronic device 800 may also include one or more of an input portion 806 including a keyboard, mouse, etc., an output portion 807 including a display such as a Cathode Ray Tube (CRT), liquid Crystal Display (LCD), etc., and speakers, etc., a storage portion 808 including a hard disk, etc., and a communication portion 809 including a network interface card such as a LAN card, modem, etc., connected to the I/O interface 805. The communication section 809 performs communication processing via a network such as the internet. The drive 810 is also connected to the I/O interface 805 as needed. A removable medium 811 such as a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, or the like is mounted on the drive 810 as needed so that a computer program read out therefrom is mounted into the storage section 808 as needed.
The present invention also provides a computer-readable storage medium that may be included in the apparatus/device/system described in the above embodiments, or may exist alone without being assembled into the apparatus/device/system. The computer-readable storage medium carries one or more programs which, when executed, implement methods in accordance with embodiments of the present invention.
According to embodiments of the invention, the computer-readable storage medium may be a non-volatile computer-readable storage medium, which may include, for example, but is not limited to, a portable computer diskette, a hard disk, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of this document, a computer readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device. For example, according to embodiments of the invention, the computer-readable storage medium may include ROM 802 and/or RAM 803 and/or one or more memories other than ROM 802 and RAM 803 described above.
Embodiments of the present invention also include a computer program product comprising a computer program containing program code for performing the method shown in the flowcharts. The program code means for causing a computer system to carry out the method for quantum key distribution real-time encoding for free space provided by the embodiments of the present invention when the computer program product is run in a computer system.
The above-described functions defined in the system/apparatus of the embodiment of the present invention are performed when the computer program is executed by the processor 801. The systems, apparatus, modules, units, etc. described above may be implemented by computer program modules according to embodiments of the invention.
In one embodiment, the computer program may be based on a tangible storage medium such as an optical storage device, a magnetic storage device, or the like. In another embodiment, the computer program may also be transmitted, distributed, and downloaded and installed in the form of a signal on a network medium, and/or from a removable medium 811 via a communication portion 809. The computer program may comprise program code that is transmitted using any appropriate network medium, including but not limited to wireless, wireline, etc., or any suitable combination of the preceding.
In such an embodiment, the computer program may be downloaded and installed from a network via the communication section 809, and/or installed from the removable media 811. The above-described functions defined in the system of the embodiment of the present invention are performed when the computer program is executed by the processor 801. The systems, devices, apparatus, modules, units, etc. described above may be implemented by computer program modules according to embodiments of the invention.
Those skilled in the art will appreciate that the features recited in the various embodiments of the invention can be combined in a variety of combinations and/or combinations, even if such combinations or combinations are not explicitly recited in the present invention. In particular, the features recited in the various embodiments of the invention can be combined and/or combined in various ways without departing from the spirit and teachings of the invention. All such combinations and/or combinations fall within the scope of the invention.