CN110380841A - A kind of Electronic Document exchange encryption method based on BlockChain - Google Patents

Abstract

The present invention provides a kind of data ciphering methods, which comprises acquisition data source document by private key array K by data original file encryption, and generates ciphertext C, while generating corresponding encrypted indexes I.C, I are uploaded to server, recipient and sender share private key array K simultaneously, if recipient wants the data file that search includes keyword w, can calculate corresponding Search Flags by private key array Kt_w, while the Search Flags are uploaded to server, at this time server end by combination C, I,t_wCalculated resultC_ij, recipient can be in local decryption at this timeC_ij。

Description

Electronic official document exchange encryption method based on BlockChain

Technical Field

The invention relates to the field of data security, in particular to an electronic official document exchange encryption method.

Background

The data contains a great deal of visual and hidden values, but how to develop, perfect and reasonably protect the data becomes the first problem to be solved nowadays.

The electronic document exchange system needs interactive cooperation of information management and a resource exchange mechanism, and accordingly, the management mechanism of the electronic document is optimized. It can be known in bitcoin and other cryptocurrency block chains that resource mining gradually rises to a bottleneck, a user can conveniently access cloud-end data on any equipment, and the existing Searchable Symmetric Encryption (SSE) scheme needs to pay before searching, which is unfair for the user, so that a novel electronic document exchange encryption method is needed to protect the data in the electronic document and ensure the safety and reliability of the data.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide the electronic document exchange encryption method, the provided method realizes safer monitoring management and authorization functions, and has the advantages of high data access safety factor, optimized resource monitoring, reduced resource consumption and the like.

The invention aims at an electronic official document exchange encryption method, which can comprise the following steps: and collecting a data source document, encrypting the data original document through a private key array K, generating a ciphertext C, and generating a corresponding encryption index I. C, I is uploaded to a server, the receiver and the sender share the private key array K at the same time, if the receiver wants to search the data document containing the keyword w, the corresponding search identification can be calculated by the private key array Kt_wAnd at the same time, uploading the search identifier to the server, wherein the server side passes through the combination C, I,t_wCalculation resultsC_ijAt this point, the receiver can decrypt locallyC_ij。

The source data collected may be a data warehouse, in-server data, etc.

The private key array firstly provides a security parameter k for data in the process of encrypting the original document and outputs the private key arrayK=(k₁,k₂,k₃,k₄,k₅)。

The index generation first extracts keywords from the document, and for each keywordw_i∈WNull set should be setDB（w_i) If the jth document contains keywordsw_iThen, thenDB(w_i)[j]Is set to 1, otherwise, willDB(w_i)[j]Is set to 0.

Wherein,tw_i，ew_i，Macw_ithe value of (c) will be calculated as follows:

tw_i=F₁(K₂,w_i||0)

kw_i=F₁(K₂,w_i||1)

ew_i= 𝛿.Enc(K=kw_i,DB(w_i))

kw_i=F₁(K₃,w_i)

Macw_i =H(Kw_i||DB(w_i))

at this time, willtw_i，ew_i，Macw_iPut into a length ofm·（2k +λ) C, I is finally uploaded to the server.

The search identification of the document containing the keyword w is calculated through the private key arrayT_wShould be calculated as follows:

t_w=F₁(k₂,w|| 0)

k_w=F₁(k₂,w|| 1)

k₃₁=F₁(k₄,w_i)

T_w= 𝛿.Enck(k₃₁,t_w||k_w||H(k₃₁))

when the server side combines and calculates the output result, ask and Pay are calculated through search algorithm, and then Reed is usedAnd the Dec algorithm calculates the Redeem,D_j。

The fairness is based on the block chain technique being irreversible, and if the user and the server are not honest, then Pay cannot be accepted by the block chain.

When the search mode is executed, the user and the server carry out six times of interaction, and the intelligent contract is realizedD(. a) andSHA256，V(x，y) AndAESandSHA256, the contract may automatically determine whether the embedded result is valid.

Drawings

Fig. 1 shows a flow chart of an electronic document exchange encryption algorithm according to an example embodiment of the present invention.

Detailed Description

As shown in fig. 1, an embodiment of the present invention provides an electronic document exchange encryption method.

First, a source data document is collected in step S101, and user data is derived from data in a data warehouse and a server.

Next, in step S102, after the data owner takes the parameter K as input, the key array K = (K =) can be correctly outputk₁,k₂,k₃,k₄,k₅）。

In generating the ciphertext C in step S103, the ciphertext C should be calculated using the private key and the source document as follows.

C_i=ε.Enc_k1(D_i)(1 ≤i ≤n)

MAC(C_i)=(K₅,C_i)

C←（（C₁，MAC（C₁）），...，（C_n，MAC（C_n）））

Generating the index first extracts keywords from the documents, for each keywordw_i∈WNull set should be setDB（w_i) If the jth document contains keywordsw_iThen, thenDB(w_i)[j]Is set to 1, otherwise, willDB(w_i)[j]Is set to 0.

Wherein,tw_i，ew_i，Macw_ithe value of (c) will be calculated as follows:

tw_i=F₁(K₂,w_i||0)

kw_i=F₁(K₂,w_i||1)

ew_i= A.Enc(K=kw_i,DB(w_i))

kw_i=F₁(K₃,w_i)

Macw_i =H(Kw_i||DB(w_i))

at this time, willtw_i，ew_i，Macw_iPut into a length ofm·（2k +λ) C, I is finally uploaded to the server.

The data owner shares the key array k with the user in step S104, and when searching for a document containing the keyword w, it should be obtained by the following calculationT_wAnd upload it to the server.

t_w=F₁(k₂,w|| 0)

k_w=F₁(k₂,w|| 1)

k₃₁=F₁(k₄,w_i)

T_w=A.Enck(k₃₁,t_w||k_w||H(k₃₁))

In step S105, a value ofdNon-redemption of BT_s1Then will beV(k₃₁，T_w) Is embedded intoaskIn the script of (2), the user outputs the main body of the Pay using ask, and propagates the Pay value.

The calculated should be used in step S106t_w，e_w，Mac_wAnd usek_w:DB(w)=𝛿.Dec(k_w,e_w) Decryptione_w. Setting of empty collectorC_wAnd will beMAC(C_j) Is put intoC_w，Thereafter will beTu₁AndTu₂the main body Get is output as input, and the script of pro is output by Get.

Using the key in step S107k₁To pairC_j：D_j=ε.Dec(K₁，C_j) Decryption, and finally updating by new keyC_iIs/are as followsMAC(C_i) Deleting old cloud storage endMAC(C_i)。

Claims (6)

1. A blockachain-based electronic document exchange encryption method, the method comprising:

collecting a source data document;

the encryption and decryption process of the data document is completed through the combination of seven polynomial time algorithms;

according to the probability encryption algorithm, a security parameter K is used as Gen algorithm input, and a key array K is output;

using a key arrayK=(k₁,k₂,k₃,k₄,k₅) And the data document set D is used as an Enc algorithm input item, and a ciphertext C and a reversible index I are output;

with private key array K and keyWord w andT_uas input item of Srchtoken algorithm, the search token is obtained through the outputt_wAnd Appoint;

based on search tokenst_wA key array K and a key word w andTs₁as Search algorithm input, outputting ask and Pay;

according to the Verify algorithm, ask and Pay, index I, ciphertext C and key arrays K and KTu₁、Tu₂As input, simultaneously outputting Get and save;

the obtained Appoint, Get and Prove are used as the input of the Rede algorithm, the Redeem is output, the key array K, Prove is used as the input of the Dec algorithm, and the receiver obtains the plaintext at this timeD_j。

2. The method of claim 1, wherein the data documents are derived from data warehouses and intra-server data.

3. The method of claim 1, wherein the private key encrypts the data document according to the following formula, and finally generates the ciphertext C:

Ci=ε.Enck1(Di)(1 ≤ i ≤ n)

MAC(Ci)=(K5,Ci)

C←（（C1，MAC（C1）），...，（Cn，MAC（Cn）））。

4. the method of claim 1, wherein the reversible index is generated by extracting a keyword from the document set D, setting a null array DB (wi), setting a corresponding DB value according to whether the keyword is contained in the document, if yes, DB (wi) [ j ] =1, otherwise, DB (wi) [ j ] = 0.

5. The method of claim 1, wherein the fairness is based on block chain technology is irreversible, and if the user and the server are not honest, then Pay cannot be accepted by the block chain.

6. The method of claim 1, wherein the search mode is performed with six interactions by the user with the server, implementing a combination of smart contracts D (-) and SHA256, V (x, y) with AES and SHA256, which automatically determines whether the embedded results are valid.