CN111130793A - File encryption method based on block chain bidding system - Google Patents

Abstract

The invention discloses a file encryption method based on a block chain bidding system, which comprises the following steps: 1) a bidder imports a bid file F at a client, the client randomly generates an AES key, and the F is encrypted by using an AES algorithm to generate F'; 2) uploading F ' to an IPFS by a client, taking a hash value for the F ' by the client to obtain Hf, adding a random number uuid behind the Hf to obtain m, and blinding the m by using a blind signature algorithm to obtain m '; 3) the client sends m ' to the server for signature, and the server signs m ' by using a private key to obtain s '; 4) the client sends s 'to the intelligent contract, the intelligent contract verifies the validity of the signature of the tenderer, if the signature is valid, the client removes the blindness of s' to obtain s, and if the signature is invalid, the client goes to 3); 5) and the client sends the s and the m to the intelligent contract for verification, and if the verification is successful, the m is stored in the block chain. The invention ensures the safe storage of the bidding document.

Description

File encryption method based on block chain bidding system

Technical Field

The invention relates to the field of block chains, in particular to a file encryption method based on a block chain bidding system.

Background

The electronic bidding is a bidding activity completed in a data telegraph text form. Generally speaking, paper documents are partially or completely abandoned, and bidding activities are completed by means of computers and networks. Electronic bidding brings convenience, quickness and cost reduction benefits, and meanwhile, has a plurality of problems. The main problem is network information security, and network security problems may occur in many links in the whole process of electronic bidding, such as identity authentication of electronic buyers and sellers, host and object of data communication, and secure transmission of information data. At present, in electronic bidding activities, the security of electronic file data is not high enough, and the electronic file data is easy to be tampered.

The randow provides a block chain-based bid inviting and bidding processing method and system, processing steps of bid inviting, bidding, bid opening, bid evaluation, bid winning and the like are stored in each block and a private chain for solving, the openness and fairness of each link are guaranteed, the time sequence of data is guaranteed, and the data can be traced. However, only for the encryption of the bidding document, a symmetric encryption method is used as a main method, and the encryption algorithm is single, so that the absolute security of the bidding document cannot be guaranteed, and therefore, an encryption mode capable of guaranteeing higher security of bidding document information needs to be designed, so that the tenderer and the bidder can complete fair and fair bidding activities on line.

The full-state star proposes encryption distribution based on block chain sensitive information, and introduces how to encrypt and decrypt bidding information by using a secure hash algorithm, an RSA algorithm and the like. The full-armor star uses SHA-256 algorithm to encrypt the single notice attachment information in the notice attachment information to prevent the notice attachment information from being falsified. And adding RSA signature algorithm to carry out signature verification on the notice information. In the public platform for bidding of the block chain, the public platform for bidding indicates that the public platform for bidding of the block chain adjusts the advertisement information field of the block, adds the sensitive information field and encrypts the sensitive field. Although the full-bore star optimizes the encryption and decryption method of the bidding and bidding announcement information, the RSA algorithm key is lower than 1024 bits in the decryption process, and the decomposition of RSA-512 is relatively simple for individual users, so that potential safety hazards exist. In addition, the encryption method only encrypts a single link of the issued announcement in the bidding process, and does not relate to links such as bidding, bid evaluation, bid opening, scaling and the like, so that a block chain technology and a safe encryption algorithm are required to be designed to be applied to more links in the bidding process, and the whole bidding process is more standard and safe.

Plum proposes a block chain technology-based encryption algorithm application study for Liu Shi cloud, points out that the realization of the function of the block chain needs to solve the security problem, and further leads out an RSA encryption algorithm. The method adopts an RSA encryption algorithm to ensure the security of data in a block chain technology network, and obtains the process of RSA encryption and decryption through simulation. However, only the encryption algorithm combined with the block chain technology is proposed, and is not applied to the bidding environment, so that a block chain encryption algorithm adapted to the bidding environment needs to be designed to combine the algorithm with the actual application.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention aims to provide a file encryption method based on a block chaining bidding system.

A file encryption method based on a block chaining bidding system comprises the following steps:

1-1) a bidder imports a bid file F at a client, the client randomly generates an AES key (the key is only held by the bidder), and the F is encrypted by using an AES algorithm to generate F';

1-2) uploading F ' to an IPFS (distributed file storage system) by a client, obtaining Hf by the client by taking a hash value of F ', adding a random number uuid behind the Hf to obtain m, and blinding m by using a blind signature algorithm to obtain m ';

1-3) the client sends m ' to the server for signature, and the server signs m ' by using a private key to obtain s ';

1-4) the client sends s 'to the intelligent contract, the validity of the signature of the tenderer is verified by the intelligent contract, if the signature is valid, the client removes blindness from s' to obtain s, and if the signature is invalid, the client goes to 1-3);

1-5) the client sends s and m to the intelligent contract for verification, and if the verification is successful, m is stored in the block chain.

In the steps 1-5), the implementation process is as follows:

2-1) the client of the tenderer generates a random account number, and s and m are sent to the intelligent contract through the random account number for verification;

2-2) if m is obtained after s is successfully signed, resolving m to obtain Hf and uuid, then checking is successful, and the client side of the tenderer stores m to the block chain; otherwise, the check fails and an error is returned.

The invention has the following beneficial effects:

1. the method and the system realize the complete unknown guarantee between the bidder and the tenderer, and the tenderer can guarantee the validity and the authentication operation of the file under the condition of guaranteeing the complete anonymity of the process file before the tendering.

2. Any link of the bidding document file before the opening of the bidding document is in an anonymous and encrypted state, so that the possibility of tampering and stealing the bidding document is almost zero.

3. The intelligent contract has zero knowledge proof characteristic, each step of operation of the intelligent contract leaves a record on the chain, and both sides can self-prove and clear due to the non-tamper property of the block chain, so that the trust cost between the bidder and the tenderer is reduced.

Detailed Description

The invention will be further illustrated and described with reference to the following examples. The technical features of the embodiments of the present invention can be combined correspondingly without mutual conflict.

A file encryption method based on a block chaining bidding system comprises the following steps:

1-1) a bidder imports a bid file F at a client, the client randomly generates an AES key (the key is only held by the bidder), and the F is encrypted by using an AES algorithm to generate F';

1-2) uploading F ' to an IPFS (distributed file storage system) by a client, obtaining Hf by the client by taking a hash value of F ', adding a random number uuid behind the Hf to obtain m, and blinding m by using a blind signature algorithm to obtain m ';

1-3) the client sends m ' to the server for signature, and the server signs m ' by using a private key to obtain s ';

1-4) the client sends s 'to the intelligent contract, the validity of the signature of the tenderer is verified by the intelligent contract, if the signature is valid, the client removes blindness from s' to obtain s, and if the signature is invalid, the client goes to 1-3);

1-5) the client sends s and m to the intelligent contract for verification, and if the verification is successful, m is stored in the block chain.

A file encryption method based on a block chaining bidding system is characterized in that in the step 1-5), the implementation process is as follows:

2-1) the client of the tenderer generates a random account number, and s and m are sent to the intelligent contract through the random account number for verification;

2-2) if m is obtained after s is successfully signed, resolving m to obtain Hf and uuid, then checking is successful, and the client side of the tenderer stores m to the block chain; otherwise, the check fails and an error is returned.

Examples

To facilitate the understanding and practice of the present invention by those of ordinary skill in the art, a specific embodiment of the method of the present invention will now be presented. The file encryption method based on the block chain bidding system fully utilizes the characteristics and advantages of the block chain, the RSA algorithm, the Hash algorithm and the blind signature algorithm, solves the problem of safety of current bidding data, and provides a more safe and transparent file encryption method.

In this embodiment, a company A intends to purchase a collection of displays by tender. Company a uses the system to issue a bidding announcement. The specific requirements are shown in table 1.

Bidding project name: display procurement

The item guarantee amount: 2000

Item bidding start time: 2018-05-15

Ciphertext submission end time: 2018-05-25

Item bidding end time: 2018-06-10

Minimum bid number for project: 2

TABLE 1 display requirements of company A

The three companies A, B and C know the specific requirements of the company A on bid by inquiring the bid-inviting announcement and successively and online propose bid applications to the company A. After obtaining the application, three companies A, B and C upload bid documents F1, F2 and F3 respectively on the client. The client randomly generates three pairs of AES keys, and F1, F2 and F3 are encrypted respectively by using an AES algorithm to obtain F1 ', F2 ' and F3 '.

TABLE 2 Bidding of three companies

Company A	Company B	C Corp Ltd
			F1	F2	F3

TABLE 3 company Bid content

Detailed description of the invention	Size of	Resolution ratio	Degree of refresh	Brightness of light	Unit price of
						Bidding content	24	1K	60	250	1199

TABLE 4 Bid Contents

Detailed description of the invention	Size of	Resolution ratio	Degree of refresh	Brightness of light	Unit price of
						Bidding content	27	4K	60	350	3299

TABLE 5C Bidding content

Detailed description of the invention	Size of	Resolution ratio	Degree of refresh	Brightness of light	Unit price of
						Bidding content	24	1K	60	250	789

TABLE 6A company Biddings encryption

AES key	bj3kHJI2jh41jur93FH
		F1’	jnpTfJHH+SCtaTgqxpN9fHx/r0BVyzQlx8LD9KFRpkE=

TABLE 7B company Biddings encryption

AES key	ihurfqw6574ddw652ed
		F2’	qTke3/QXjSu1CUZw3DeuUtBt4PdfHHT54f0NDlwwWM8=

TABLE 8C company Biddings encryption

AES key	kdsfbjw872kwi8w2jwwe2e2k
		F3’	sseMtT4PZw80aDHMnMlTn8eCHTuZRkKjuls36mtg2L0=

The client uploads the encrypted files F1 ', F2' and F3 'to the IPFS respectively, and takes hash values of F1', F2 'and F3' to obtain Hf1, Hf2 and Hf3 respectively.

Table 9 encryption Bidding hash value

Hf1	a5080104a6d50c8a85262d36cbf74eab9a3eb4a66d56fdd4f7ded44334b7b802
		Hf2	06a8fae940ccabecc6646cd9698358965f47383051d20d77eeef1ddbfd3f7f6d
Hf3	46415f99320a989325ed063a3aff0d74a4bdc6888d9957c2ed6e2ac23a0de0

The client adds random numbers uuid1, uuid2 and uuid3 after the hash values Hf1, Hf2 and Hf3 respectively to obtain m1, m2 and m 3.

TABLE 10A Cryptographic addition random number

Hf1	a5080104a6d50c8a85262d36cbf74eab9a3eb4a66d56fdd4f7ded44334b7b80
		uuid1	uuid{qvxcewptvotwjbve}
m1	a5080104a6d50c8a85262d36cbf74eab9a3eb4a66d56fdd4f7ded44334b7b802uuid{qvxcewptvotwjbve}

TABLE 11B company ciphertext appending random number

Hf2	06a8fae940ccabecc6646cd9698358965f47383051d20d77eeef1ddbfd3f7f6d
		uuid2	uuid{edzydbfwpqpqlmfy}
m2	06a8fae940ccabecc6646cd9698358965f47383051d20d77eeef1ddbfd3f7f6duuid{edzydbfwpqpqlmfy

TABLE 12C ciphertext ADDING RANDOM NUMBER

Hf3	46415f99320a989e25ed063a3aff0d74a4bdc6888d9957c2ed6e5e2ac23a0de0
		uuid3	uuid{qasaorhiaomnsfto}
m3	46415f99320a989e25ed063a3aff0d74a4bdc6888d9957c2ed6e5e2ac23a0de0uuid{qasaorhiaomnsfto}

The client side respectively blinds m1, m2 and m3 by using a blind signature algorithm to obtain m1 ', m2 ' and m3 '; the client side sends m1 ', m2 ' and m3 ' to the server for signature, and the server side signs m1 ', m2 ' and m3 ' by using a private key to obtain s1 ', s2 ' and s3 '.

Watch 13 blinding

TABLE 14 private Key of Bidding

Company(s)	Signature private key
		A	353543768370652810909875977996662029267676041776692723383222626168573263872
B	52659416512935271099904227995352748058050342166457930265410964719284359528448
		C	21395183056351271679224886452430563801672963618705005228507133440019639828480

TABLE 15A company signs each blind label

Company(s)	Signature ciphertext
		s1’	417813214086051801172299761555683317985574960277767116656822037758556214292
s2’	997499559078896871756544784060543197596631915054786463217910134590883458540
		s3’	1134042982415102019994507682132730044542351236954908744302469034432436245225

The client side sends s1 ', s 2' and s3 'to the intelligent contract respectively to check the validity of the signature of the company A, if the signature is valid, s 1', s2 'and s 3' are blinded to obtain s1, s2 and s 3; if not, the signature is reinitiated.

TABLE 16 Blind removal

s1	407843721258687185499632414649544394783569158755562858739605128194653842074
		s2	29379553922896757776509293233661646443670127839201157116641156056003689919188
s3	20885760979870704405422622932318070471408154373845334373482441288410748560662

The client generates random account numbers r1, r2 and r3, and s and m are sent to the intelligent contract through the random account numbers (consisting of Address and Privkey) to be verified; if m is obtained after s is successfully signed, resolving m to obtain Hf and uuid, then checking successfully, and storing m to the block chain by the client; otherwise, the check fails and an error is returned.

TABLE 17 random Account number

	Address	Privkey
			r1	1865395204908298151104826047228711880633095784713438137095874058349859949023331937192502391188129495230680634168192693719340908986744844498786077051644773	3316221033886075137115213077544289300213993542200343317624474881563696219610941719786993381968380995749843630419082151202556972248661512362529547489259757
r2	120214962853234525524124259732258382874402916893583701009502862527439196821048615056121266288776939857550830527819565503129214056563680863532236827725085	518691876112864156952680718827884935279352084844592986151063567955295729390047829346022837346003287955557103541065256669735430964275772388758916699167105
			r3	5868269337901128562453582804290730466313974800597077295121672900713008097703077051619178455234916256971259029192545301095775577440860294469517764601721	3736318219887411804028413902041868898687001383016830816875798234444210401003724847723680361187591792788685496643646180064106083597234616741968690735045

TABLE 18 De-signature s

m1	a5080104a6d50c8a85262d36cbf74eab9a3eb4a66d56fdd4f7ded44334b7b802uuid{qvxcewptvotwjbve}
		m2	06a8fae940ccabecc6646cd9698358965f47383051d20d77eeef1ddbfd3f7f6duuid{edzydbfwpqpqlmfy
m3	46415f99320a989e25ed063a3aff0d74a4bdc6888d9957c2ed6e5e2ac23a0de0uuid{qasaorhiaomnsfto}

TABLE 19 m analysis

Hf1	a5080104a6d50c8a85262d36cbf74eab9a3eb4a66d56fdd4f7ded44334b7b80
		uuid1	uuid{qvxcewptvotwjbve}
Hf2	06a8fae940ccabecc6646cd9698358965f47383051d20d77eeef1ddbfd3f7f6d
		uuid2	uuid{edzydbfwpqpqlmfy}
Hf3	46415f99320a989e25ed063a3aff0d74a4bdc6888d9957c2ed6e5e2ac23a0de0
		uuid3	uuid{qasaorhiaomnsfto}

Claims (2)

1. A file encryption method based on a block chaining bidding system is characterized in that safe storage of bidding files in the system is guaranteed, and the method comprises the following steps:

a bidder imports a bid file F at a client, the client randomly generates an AES key (the key is only held by the bidder), and the F is encrypted by using an AES algorithm to generate F';

uploading F ' to an IPFS (distributed file storage system) by a client, obtaining Hf by the client by taking a hash value of the F ', adding a random number uuid behind the Hf to obtain m, and blinding the m by using a blind signature algorithm to obtain m ';

the client sends m ' to the server for signature, and the server signs m ' by using a private key to obtain s ';

the client sends s 'to the intelligent contract, the intelligent contract verifies the validity of the signature of the tenderer, if the signature is valid, the client removes the blindness of s' to obtain s, and if the signature is invalid, the client goes to 1-3);

and the client sends the s and the m to the intelligent contract for verification, and if the verification is successful, the m is stored in the block chain.

2. The file encryption method based on the block chaining bidding system according to claim 1, wherein the steps 1-5) are implemented as follows:

2-1) the client of the tenderer generates a random account number, and s and m are sent to the intelligent contract through the random account number for verification;

2-2) if m is obtained after s is successfully signed, resolving m to obtain Hf and uuid, then checking is successful, and the client side of the tenderer stores m to the block chain; otherwise, the check fails and an error is returned.