CN115174152B - A group test authentication encryption method, verification and decryption method and communication method - Google Patents

Abstract

The present invention discloses a group test authentication encryption method, a verification and decryption method and a communication method, which relate to the field of information security. Aiming at the data expansion problem of traditional authentication encryption schemes, the authentication encryption scheme is combined with a group test method, which can effectively reduce the amount of data transmission when using the authentication encryption scheme for confidential communication, and the method has strong practicality.

Description

A group test authentication encryption method, verification and decryption method and communication method

Technical Field

The present invention relates to the field of information security, and in particular to a group test authentication encryption method, a group test verification decryption method and a communication method.

Background technique

Authenticated Encryption is a cryptographic scheme that can provide both encryption and authentication functions. Encryption ensures the confidentiality of data, that is, it will not leak plaintext information, and authentication ensures the integrity of data, that is, it ensures that the transmitted data is not tampered with by the adversary, and at the same time, the source of the message can be confirmed. The encryption algorithm input of the authenticated encryption scheme is the key, initialization vector, associated data, and plaintext, where the associated data is the data that does not need to be encrypted for transmission but only needs to be guaranteed not to be tampered with, and the plaintext is the data that needs to be encrypted for transmission, and the output is the ciphertext and the message authentication code; the decryption algorithm input is the key, initialization vector, associated data, ciphertext, and authentication code. The decryption algorithm regenerates the message authentication code and compares it with the received message authentication code to determine whether the ciphertext is valid. If they are consistent, the corresponding plaintext is generated and output.

The group testing method originated from the blood sample test during World War II - how to quickly find infected people from a large number of blood samples with as few tests as possible. Group testing is divided into adaptive and non-adaptive. Adaptive group testing is generally a multi-step group test, and the subsequent grouping strategy depends on the previous test results; non-adaptive group testing only requires one step to perform multiple tests, and these tests can be performed simultaneously, which is more conducive to application in practical problems. Therefore, the present invention uses non-adaptive group testing. This method is generally characterized by a group test matrix.

During data transmission, users may generate a large number of short messages. For example, when editing online documents, operations such as adding, deleting, modifying, and revoking may occur. Each operation can be regarded as a short message. In the process of communicating with the server, the initial vectors and authentication codes generated when authenticating and encrypting these messages will cause a large amount of data expansion, which greatly affects the efficiency of network transmission.

Combining multiple short messages into one long message and then processing it with the authentication encryption algorithm can greatly reduce the data expansion of the authentication code, but when the decryption verification fails, it is impossible to determine which short message has a problem, which will cause all messages to be retransmitted. If the location of the message error can be detected with the smallest possible data expansion, the amount of network data transmission will be greatly reduced.

In view of this, how to reduce data expansion and detect the location of error messages in authenticated encryption has become a technical problem that needs to be solved.

Summary of the invention

The purpose of the present invention is to address the data expansion problem of traditional authentication encryption schemes, combine authentication encryption schemes with group testing methods, and provide a group test authentication encryption method applied to a sending end, and a corresponding group test verification decryption method applied to a receiving end, as well as a communication method including group test authentication encryption and group test verification decryption, which can effectively reduce the amount of data transmission when using authentication encryption schemes for confidential communications, and the method has strong practicality.

To achieve the above object, the present invention adopts the following technical solutions:

The present invention provides a group test authentication encryption method, which is applied to a sending end and comprises the following steps:

Encrypting a set of message pairs consisting of plaintext and associated data using an encryption algorithm of an authenticated encryption scheme to generate ciphertext and a corresponding first initial message authentication code;

Generate an intermediate value using a group test matrix according to the first initial message authentication code;

The intermediate value is encrypted to generate a first final message authentication code; and the initial vector of the encryption algorithm, the associated data, the ciphertext and the first final message authentication code are sent to a receiving end.

The beneficial effect of the above technical solution is: a general group test authentication encryption method is provided. Since the number of final message authentication codes is much smaller than the number of messages, data expansion can be effectively prevented and the amount of data transmitted during communication can be reduced. For example, in industrial control systems, large amounts of data need to be transmitted frequently. This method can be used to perform group tests on the authentication encrypted data to be transmitted by the sender, which can effectively improve communication efficiency.

Furthermore, the generating of ciphertext and corresponding message authentication code specifically includes: the sending end and the receiving end share a set of keys K ₁ , and according to the initial vector, by calling the encryption algorithm of the authentication encryption scheme, encrypt the plaintext and associated data to generate ciphertext and corresponding first initial message authentication code.

Furthermore, the generating the intermediate value specifically includes: dividing the first initial message authentication code into a plurality of groups according to the group test matrix, and performing XOR operation on the values in each group to generate the intermediate value.

The beneficial effect of the above steps is that the use of the group test matrix can effectively reduce the number of message authentication codes generated when encrypting massive data and reduce the amount of data transmitted during communication.

Furthermore, the generating of the final message authentication code specifically includes: the sending end and the receiving end share another set of keys K ₂ , and according to the intermediate value, encrypt the intermediate value by calling an adjustable block cipher to obtain the first final message authentication code.

The beneficial effects of the above steps are: using the adjustable block cipher to generate a message authentication code has high security, and the method is simple and universal.

Furthermore, the authentication encryption scheme selects the CCM algorithm.

The present invention also provides a group test verification decryption method, which is applied to a receiving end and comprises the following steps:

Receiving the initial vector, associated data, ciphertext and the first final message authentication code sent by the sender, decrypting the ciphertext using the decryption algorithm of the same authentication encryption scheme, and generating plaintext and the corresponding second initial message authentication code;

generating an intermediate value using a group test matrix according to the second initial message authentication code;

The intermediate value is encrypted to generate a second final message authentication code, and compared with the received first final message authentication code, the position of the invalid ciphertext is determined according to the group test method and the remaining corresponding plaintext is output.

The beneficial effect of the above technical solution is: a universal group test verification decryption method is provided, which is used to reduce the amount of data transmission during communication while detecting the location of error messages. Only a small amount of message authentication code needs to be transmitted to achieve the purpose of verifying the validity of the ciphertext. If the calculated message authentication code is legal, it indicates that the data received by the receiving end has not been tampered with, otherwise it indicates that the data has been tampered with.

Furthermore, generating the plaintext and the corresponding second initial message authentication code specifically includes: the receiving end and the sending end share a set of keys K ₁ , decrypting the received ciphertext by calling the decryption algorithm of the authenticated encryption scheme according to the received initial vector and associated data, and generating the plaintext and the corresponding second initial message authentication code.

Furthermore, the generating the intermediate value specifically includes: dividing the second initial message authentication code into a plurality of groups according to the group test matrix, and performing XOR operation on the values in each group to generate the intermediate value.

Furthermore, the generating of the second final message authentication code specifically includes: the receiving end and the sending end share another set of keys K ₂ , and according to the intermediate value, encrypt the intermediate value by calling an adjustable block cipher to obtain the second final message authentication code.

The present invention also provides a communication method including group test authentication encryption and group test verification decryption, which includes the following steps:

The sending end encrypts a message pair consisting of plain text and associated data using an encryption algorithm of an authenticated encryption scheme to generate a ciphertext and a corresponding first initial message authentication code; generates an intermediate value based on the first initial message authentication code using a group test matrix; encrypts the intermediate value to generate a first final message authentication code; and sends the initial vector of the encryption algorithm, the associated data, the ciphertext, and the first final message authentication code to the receiving end;

The receiving end receives the initial vector, associated data, ciphertext and the first final message authentication code sent by the sending end, decrypts the ciphertext using the decryption algorithm of the same authentication encryption scheme, generates plaintext and the corresponding second initial message authentication code; generates an intermediate value based on the second initial message authentication code using a group test matrix; encrypts the intermediate value to generate a second final message authentication code, and compares it with the received first final message authentication code, determines the position of the invalid ciphertext according to the group test method, and outputs the remaining corresponding plaintext.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of a group test authentication encryption method flow chart provided in Embodiment 1 of the present invention;

FIG2 is a schematic diagram showing the principle of a group test authentication encryption method provided in Example 1 of the present invention;

FIG3 is a schematic diagram of a group test verification decryption method flow chart provided in Embodiment 3 of the present invention;

FIG. 4 is a schematic diagram showing the principle of a group test verification and decryption method provided in Embodiment 3 of the present invention.

Detailed ways

In order to make the above features and advantages of the present invention more obvious and easy to understand, embodiments are given below and described in detail with reference to the accompanying drawings.

Example 1

As a specific embodiment of the present invention, a group test authentication encryption method applied to a sending end is disclosed, as shown in FIG1 , comprising the following steps:

S1. The sender and the receiver share a set of keys K ₁ , and encrypt m groups of messages (A _i , _Pi ), i=1,2,…,m according to the initial vector N, to generate ciphertext and the corresponding first initial message authentication code (C _i ,S _i ), i=1,2,…,m, where the associated data _Ai is the data to be transmitted in plain text, and Pi _is the plain text to be encrypted;

S2. Generate an intermediate value X _j , j=1,2,…,t using the group test matrix according to the first initial message authentication code;

S3. Share another set of keys K ₂ with the receiving end, generate a first final message authentication code T = (T ₁ , T ₂ , …, T _t ), t≤m according to the intermediate value X _j , j = 1, 2, …, t; and send (N, (A ₁ , C ₁ ), …, (A _m , C _m ), (T ₁ , T ₂ , …, T _t )) to the receiving end.

Compared with the prior art, this embodiment provides a general group test authentication encryption method for reducing the amount of data transmission during communication, especially reducing the number of initial vectors N and message authentication codes S. FIG2 shows a schematic diagram of the principle of the group test authentication encryption method provided by Embodiment 1 of the present invention.

Example 2

Based on the optimization of Example 1, step S1 further includes:

S11. The sender and the receiver share a key K ₁ , encrypt m groups of messages (A _i , _Pi ), i=1,2,…,m, and generate ciphertext and the corresponding first initial message authentication code (C _i ,S _i ), i=1,2,…,m by the following formula:

ε(K ₁ ,N||i,A _i ,P _i )＝(C _i ,S _i ),i＝1,…,m

Where ε is the encryption algorithm of the authenticated encryption scheme, which generates the ciphertext C = (C ₁ , C ₂ , ..., C _m ) and the corresponding first initial message authentication code S = (S ₁ , S ₂ , ..., S _m ). N||i is used as the initial vector actually used during encryption.

Preferably, the above authentication encryption scheme can use the CCM algorithm.

The step S2 further comprises:

S21. Divide the first initial message authentication code S _i , i=1,2,…,m obtained above into t groups by using the following group test matrix Q _j×i , and XOR the S _i in each group to generate an intermediate value X _j , j=1,2,…,t, where t≤m;

For example, when t=9 and m=15, the group test matrix can be selected as:

Each row of the above matrix Q _9×15 represents the grouping information of the intermediate value. If a _ji = 1, the jth group contains S _i . Otherwise, a _ji = 0 means that the jth group does not contain S _i . Finally, the 15 message authentication codes S _i can be divided into 9 groups, and the values of each group are XORed separately to obtain X _j , j = 1, 2, ..., 9. The error detection capability of the group test matrix is determined by the maximum value of d in the property that any column of the group test matrix not exceeding d does not contain the bitwise OR of other columns. The error detection capability of the above matrix Q _9×15 is 1, which means that if one ciphertext data is tampered with during transmission, the error position can be accurately found. If more than 1, the error position cannot be accurately found.

The step S3 further comprises:

S31. The sender and the receiver share a key K ₂ , and obtain the first final message authentication code T = (T 1 , T 2 , ..., T _t ), t ≤ m according to the above-obtained X _j , j = ₁ , ₂ , ..., t by the following formula:

Where F is a tunable block cipher and the tuning handle is j.

Example 3

As a specific embodiment of the present invention, a group test verification decryption method applied to a receiving end is disclosed, as shown in FIG3 , comprising the following steps:

S4. The receiving end receives the data (N′, (A′, C′), T′) sent by the sending end, initializes P ^* = ⊥, set Share the key K ₁ with the sender, decrypt the ciphertext C' according to the initial vector N' and the associated data A', and generate the plaintext and the corresponding second initial message authentication code/>

S5. The second initial message authentication code obtained according to the above calculation Use the group test matrix to generate intermediate values/> j＝1,2,…,t；

S6. The receiving end and the sending end share the key K ₂ , and the above intermediate value j＝1,2,…,t encryption, generate the second final message authentication code/> According to the group test method, each component of T ^* is determined. Is it consistent with each component T' _j of T'? If so, the components involved in the generation of The message sequence numbers corresponding to all message authentication codes S _j are from the set/> Exclude from; traverse the collection /> Will/> Set it to ⊥, and finally output P ^* .

During implementation, if the second final message authentication code T ^* is the same as the first final message authentication code T′ received by the receiving end, it indicates that the data received by the receiving end has not been tampered with; if the message authentication codes are different, it indicates that the data has been tampered with. FIG4 shows a schematic diagram of the principle of the group test verification decryption method provided by Embodiment 3 of the present invention.

Example 4

Based on the optimization of Example 3, step S4 further includes:

S41. The receiving end and the sending end share the key K ₁ , decrypt the ciphertext C′, and obtain the plaintext and the corresponding second initial message authentication code through the following formula:

in is the decryption algorithm of the authenticated encryption scheme,/> The algorithm outputs the plaintext and the corresponding second initial message authentication code/>

The step S5 further comprises:

S51. The second initial message authentication code obtained above _is converted into Divide into t groups, and divide the /> XOR is performed to generate an intermediate value/> j＝1,2,…,t, where t≤m;

The step S6 further comprises:

S61. Share the key K ₂ with the sender, according to the above j＝1,2,…,t, the second final message authentication code is obtained by the following formula/> t≤m：

Where F is a tunable block cipher and the tuning handle is j.

S62. According to the group test method, determine each component of T ^* Is it consistent with each component T' _j of T'? If so, the components involved in the generation of The message sequence numbers corresponding to all second initial message authentication codes S _j are from the set/> Exclude from; traverse the collection /> Will/> Set it to ⊥, and finally output P ^* .

Example 5

As a specific embodiment of the present invention, a communication method including group test authentication encryption and group test verification decryption is disclosed, which is specifically composed of a group test authentication encryption method applied to the sending end and a group test verification decryption method applied to the receiving end. The group test authentication encryption method is the same as the content disclosed in the above-mentioned embodiment 1, and the group test verification decryption method is the same as the content disclosed in the above-mentioned embodiment 3.

Example 6

Based on the optimization of Example 5, the group test authentication encryption method is the same as that disclosed in the above Example 2, and the group test verification decryption method is the same as that disclosed in the above Example 4.

The steps described in the embodiments of the present invention may be completed by instructing related hardware through a computer program, and the program may be stored in a computer-readable storage medium, wherein a random access memory (RAM), a read-only memory (ROM), an optical disk, and a magnetic disk may be used as the medium for storing the program.

It should be noted that, when describing the technical solution of the present invention, the limitations of “initial”, “final”, “first” and “second” are used in the name, specifically “first initial message authentication code”, “first final message authentication code”, “second initial message authentication code” and “second final message authentication code”, which are only for the convenience of distinction and expression, but are not used to redefine their meanings and do not change the original meaning of “message authentication code”.

Although the present invention has been disclosed as above by way of embodiments, it is not intended to limit the present invention. Appropriate modifications or equivalent substitutions of the technical solutions of the present invention made by ordinary technicians in the field should be included in the protection scope of the present invention. The protection scope of the present invention shall be based on what is defined in the claims.

Claims (4)

1. A group test authentication encryption method, applied to a sending end, characterized in that it comprises the following steps: Using an encryption algorithm of an authenticated encryption scheme, a message pair consisting of plain text and associated data is encrypted to generate a ciphertext and a corresponding first initial message authentication code; the generating of the ciphertext and the corresponding first initial message authentication code specifically includes: a sending end and a receiving end share a set of keys , according to the initial vector, by calling the encryption algorithm of the authentication encryption scheme, encrypting the plaintext and the associated data to generate a ciphertext and a corresponding first initial message authentication code; According to the first initial message authentication code, using a group test matrix, generating an intermediate value; the generating the intermediate value specifically comprises: according to the group test matrix, dividing the first initial message authentication code into a plurality of groups, and performing XOR on the values in each group to generate the intermediate value; The intermediate value is encrypted to generate a first final message authentication code; the generating of the first final message authentication code specifically includes: the sending end and the receiving end share another set of keys , according to the intermediate value, encrypting the intermediate value by calling an adjustable block cipher to obtain the first final message authentication code; The initial vector, associated data, ciphertext and the first final message authentication code of the encryption algorithm are sent to a receiving end. 2. The group test authentication encryption method as described in claim 1 is characterized in that the authentication encryption scheme uses the CCM algorithm. 3. A group test verification decryption method, applied to a receiving end, characterized in that it comprises the following steps: Receiving the initial vector, associated data, ciphertext and the first final message authentication code sent by the sending end, decrypting the ciphertext using the decryption algorithm of the same authentication encryption scheme, and generating plaintext and the corresponding second initial message authentication code; the generating plaintext and the corresponding second initial message authentication code specifically includes: the receiving end and the sending end share a set of keys , decrypting the received ciphertext by calling the decryption algorithm of the authenticated encryption scheme according to the received initial vector and associated data, and generating a plaintext and a corresponding second initial message authentication code; According to the second initial message authentication code, using a group test matrix, generating an intermediate value; the generating the intermediate value specifically comprises: according to the group test matrix, dividing the second initial message authentication code into a plurality of groups, and performing XOR on the values in each group to generate the intermediate value; Encrypting the intermediate value to generate a second final message authentication code, and comparing the received first final message authentication code, determining the position of the invalid ciphertext according to the group test method and outputting the remaining corresponding plaintext; generating the second final message authentication code specifically includes: the receiving end and the sending end share another set of keys , according to the intermediate value, encrypting the intermediate value by calling an adjustable block cipher to obtain the second final message authentication code. 4. A communication method, comprising the group test authentication encryption method of claim 1 and the group test verification decryption method of claim 3, characterized in that it comprises the following steps: The sending end encrypts a message pair consisting of plain text and associated data using an encryption algorithm of an authenticated encryption scheme to generate a ciphertext and a corresponding first initial message authentication code; generates an intermediate value based on the first initial message authentication code using a group test matrix; encrypts the intermediate value to generate a first final message authentication code; and sends the initial vector of the encryption algorithm, the associated data, the ciphertext, and the first final message authentication code to the receiving end; The receiving end receives the initial vector, associated data, ciphertext and the first final message authentication code sent by the sending end, decrypts the ciphertext using the decryption algorithm of the same authentication encryption scheme, generates plaintext and the corresponding second initial message authentication code; generates an intermediate value based on the second initial message authentication code using a group test matrix; encrypts the intermediate value to generate a second final message authentication code, and compares it with the received first final message authentication code, determines the position of the invalid ciphertext according to the group test method, and outputs the remaining corresponding plaintext.