CN104868989B - Encryption method for view data safe transmission - Google Patents

Abstract

The application is related to a kind of encryption method for view data safe transmission, comprises the following steps：Obtain image plaintext matrix A；3D chaos encryptions are carried out to image plaintext matrix A and obtain image ciphertext E；ECC encryptions are carried out to the 3D keys of 3D chaos encryptions；The 3D keys of ECC encryptions are generated into encryption file jointly with image ciphertext E, for transmitting.The technical scheme of the application has merged the advantages of chaos encryption and ECC encryptions, effectively increases the enciphering rate, encryption efficiency and security of traditional images encryption method.

Description

Encryption method for secure transmission of image data

technical field

This application relates to image encryption processing, in particular to an encryption method for secure transmission of image data.

Background technique

In the information age with highly developed network technology, pictures, as an important network information transmission medium, are widely used in medical, military, social and other fields, and the security problems of its transmission process have become increasingly prominent. Image information is different from text information and has its own information characteristics, such as strong correlation, large data volume, and high redundancy.

The currently commonly used chaotic image encryption transmission system simply uses linear chaotic sequences to perform chaotic encryption on image sequences. This method has poor correlation damage to images, and weak anti-reconstruction and anti-destruction attacks.

Contents of the invention

In order to overcome the problems existing in related technologies, the present application provides an encryption method for secure transmission of image data.

According to the first aspect of the embodiments of the present application, an encryption method for secure transmission of image data is provided, including the following steps:

Obtain the image plaintext matrix A;

Perform 3D chaotic encryption on the image plaintext matrix A to obtain the image ciphertext E;

ECC (Elliptic Curves Cryptography, elliptic curve cryptography) encryption is performed on the 3D key encrypted by 3D chaos;

The ECC-encrypted 3D key and the image ciphertext E are used to generate an encrypted file for transmission; wherein, performing 3D chaotic encryption on the image plaintext matrix A includes the following steps:

The 3D chaotic system model is established as follows:

ε＝C ^T x _i

Set E=(A xor X ^T +A·Y)xor Z ^T , where:

X _i ＝(integer( _xi ×K ₁ )modN)

Y _i ＝(integer(y _j ×K ₂ )modM)

Z _i ＝(integer(z _k ×K ₃ )mod256)

In the formula, X _i , Y _i , Z _i are the ith elements of the matrix X, Y, Z, K ₁ , K ₂ , K ₃ are random integers, M, N are the number of rows and columns of the image plaintext matrix A , x ₀ , y ₀ , z ₀ are randomly generated 3D key seeds, 0<x ₀ <1, 0<y ₀ <1, 0<z ₀ <1, 2.77<γ<3.0, 0<β<0.18 , 0<α<0.02, 0<δ<0.02, x _i , y _j , z _k are random sequences in x, y, z directions output by the 3D chaotic system, 0<i<N, 0<j<M, 0 <k<M×N, ε is the time calibration control quantity, and C is the system time calibration interval control matrix;

Wherein, performing ECC encryption on the 3D key encrypted by 3D chaos includes the following steps:

Obtain the image receiver's elliptic curve parameters Ep(a, b), base point G and public key K;

Set K _3D ＝x ₀ ||y ₀ ||z ₀ ||K ₁ ||K ₂ ||K ₃ , where || is an OR operator, that is, a bitwise OR operation;

Execute the BCH encoding algorithm to encode K _3D to point E _3D on Ep(a, b);

Generate a random large integer r;

Set ciphertext C ₁ =E _3D +rK, ciphertext C ₂ =rG, where rK and rG are elliptic curve scalar multiplication operations;

Wherein, generating the encrypted file jointly with the 3D key encrypted by ECC and the image ciphertext E includes the following steps:

Create binary files;

Convert C ₁ and C ₂ into binary and write them into binary files, and write the ECC ciphertext end flag at the end;

Write the image ciphertext E to the binary file in an appended manner;

Wherein, performing 3D chaotic encryption on the image plaintext matrix A also includes compressing and encoding the image ciphertext E.

Additional aspects and advantages of the application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the application. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application.

Description of drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and together with the description serve to explain the principles of the invention.

Fig. 1 shows the flow chart of the encryption method that is used for secure transmission of image data according to an embodiment of the present invention;

Fig. 2 shows the flow chart of the encryption method for secure transmission of image data according to a preferred embodiment of the present invention;

Fig. 3 shows a flow chart of a decryption method for secure transmission of image data according to an embodiment of the present invention;

Fig. 4 shows a flow chart of a decryption method for secure transmission of image data according to a preferred embodiment of the present invention;

Fig. 5 shows a flowchart for secure transmission of image data according to a preferred embodiment of the present invention.

detailed description

Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, the same numerals in different drawings refer to the same or similar elements unless otherwise indicated. The implementations described in the following exemplary examples do not represent all implementations consistent with the present invention. Rather, they are merely examples of apparatuses and methods consistent with aspects of the invention as recited in the appended claims.

Fig. 1 shows the flow chart of the encryption method for secure transmission of image data according to an embodiment of the present invention, comprising the following steps:

Step S10, obtaining the image plaintext matrix A;

Step S20, performing 3D chaotic encryption on the image plaintext matrix A to obtain the image ciphertext E;

Step S30, performing ECC encryption on the 3D key encrypted by 3D chaos;

In step S40, the ECC-encrypted 3D key and the image ciphertext E are used together to generate an encrypted file for transmission.

Currently commonly used chaotic image encryption transmission systems simply use linear chaotic sequences to perform chaotic encryption on image sequences. The influence of the actual software and hardware environment on the stability of the chaotic effect, the stability of the chaotic state of the chaotic system during the chaotic encrypted communication transmission process is poor; the lack of effective management of the chaotic key during the image encrypted transmission process leads to frequent occurrences in the chaotic image encrypted transmission system The problem of key disclosure.

However, this embodiment combines the advantages of chaotic encryption and ECC encryption, effectively improving the encryption speed, encryption efficiency and security of traditional image encryption methods. The image encryption transmission method effectively improves the encryption speed, is resistant to space reconstruction attacks, has strong performance based on regression mapping attacks, and has very high security performance. It provides a stable and reliable image data encryption transmission scheme for network image information interaction.

Fig. 2 shows a flowchart of an encryption method for secure transmission of image data according to a preferred embodiment of the present invention.

Preferably, as shown in Figure 2, step S20 includes the following steps:

A) Start the 3D chaos encryption process, including:

a. Randomly generate 3D key seeds x ₀ , y ₀ , z ₀ , where 0<x ₀ <1, 0<y ₀ <1, 0<z ₀ <1, and use x ₀ , y ₀ , z ₀ Initialize the 3D chaotic system, the 3D chaotic system model used is as follows:

S=C ^T x _i

Among them, 2.77<γ<3.0, 0<β<0.18, 0<α<0.02, 0<δ<0.02, xi, y _j , zx is the random sequence of 3D chaotic system output x, y, z direction, 0<i <N, 0<j<M, 0<k<M×N, M is the number of rows of the plaintext matrix A, N is the number of columns of the plaintext matrix A, ε is the time calibration control quantity, and C is the system time calibration interval control matrix;

b. Perform 3D chaotic encryption on the image plaintext matrix A, including:

Set E(A xor X ^T +A Y)xor Z ^T , where:

X _i ＝(integer( _xi ×K ₁ )modN)

Y _i ＝(integer(y _j ×K ₂ )modM)

Z _i ＝(integer(z _k ×K ₃ )mod256)

In the formula, X _i , Y _i , Z _i are the ith elements of the matrix X, Y, Z, K ₁ , K ₂ , K ₃ are random integers, M, N are the number of rows and columns of the image plaintext matrix A ;

c. Compress and encode the image ciphertext E encrypted by 3D chaos, including:

Set Z=C(E), where C represents an image compression coding algorithm, which may be a jpg or png image compression coding algorithm.

Preferably, as shown in Figure 2, step S30 includes:

B) Start the ECC encryption process, including:

a. Obtain the image receiver's elliptic curve parameters Ep(a, b), base point G and public key K;

b. Perform ECC encryption on the 3D chaotic encryption key, including:

Set K _3D = x ₀ || y ₀ || ₀ ||K ₁ || ₂ || ₃ ;

Execute the BCH encoding algorithm to encode K _3D to point E _3D on Ep(a,b);

Generate a random large integer r;

Set C ₁ =E _3D +rK, C ₂ =rG, where rK and rG are elliptic curve scalar multiplication operations.

Preferably, step S40 includes the following steps:

A) Create a binary file imgname.en, where the file name is consistent with the file name of the acquired image, and the suffix ends with .en;

B) Convert C ₁ and C ₂ into binary and write them into the file imgname.en, and write the ECC ciphertext end flag 0 at the end;

C) Write the image ciphertext E encrypted by 3D chaos into imgname.en in an additional way;

D) Send imgname.en to the image receiver through the network. This application does not limit the specific sending and transmission methods.

Fig. 3 shows a flow chart of a decryption method for secure transmission of image data according to an embodiment of the present invention, including the following steps:

Step S15, obtaining encrypted files;

Step S25, obtain the encrypted 3D key and image ciphertext E from the encrypted file according to the ECC ciphertext end mark in the encrypted file;

Step S35, performing ECC decryption on the encrypted 3D key to obtain the 3D key;

Step S45, using the 3D key to perform 3D chaotic decryption on the image ciphertext E to obtain the image plaintext matrix A.

This embodiment corresponds to the encryption method in the above-mentioned embodiment, and the decompression decoding method adopts the method corresponding to the encoding and compression method in the encryption process, which can be a jpg or png image decompression decoding algorithm, which combines the advantages of chaotic encryption and ECC encryption, effectively The encryption speed, encryption efficiency and security of the traditional image encryption method are improved.

Fig. 4 shows a flowchart of a decryption method for secure transmission of image data according to a preferred embodiment of the present invention.

Preferably, as shown in Figure 4, step S35 includes the following steps:

a) Generate elliptic curve parameters Ep(a, b), base point G and public key K;

b) Using elliptic curve parameters Ep(a, b), base point G and public key K to perform ECC decryption on the encrypted 3D key to obtain 3D keys: x ₀ , y ₀ , z ₀ , K ₁ , K ₂ , K ₃ .

Preferably, performing ECC decryption on the encrypted 3D key includes:

A) extract C ₁ , C ₂ from the ciphertext file imgname.en;

B) Set E _3D =C ₁ -kC ₂ , where E _3D is the BCH-encoded 3D chaotic encryption key combination value;

C) Decoding E _3D through the BCH decoding algorithm to obtain the 3D chaotic encryption key combination value K _3D ;

D) Extract 3D chaotic encryption keys x ₀ , y ₀ , z ₀ , K1, K2, K3 from K _3D by binary shift method.

Preferably, step S45 includes the following steps:

A) Use x ₀ , y ₀ , z ₀ to initialize the 3D chaotic system. The 3D chaotic system model used is as follows:

ε'＝C ^T _x '

Among them, 2.77<γ<3.0, 0<β<0.18, 0<α<0.02, 0<δ<0.02, xi, y _j , z _k is the random sequence of 3D chaotic system output x, y, z direction, 0<i<N,0<j<M,0<k<M×N, M is the number of rows of image ciphertext E, N is the number of columns of image ciphertext E, ε is the time calibration control quantity, C is the system time calibration interval control matrix, and L is the calibration gain. By selecting an appropriate L, the system and the encrypted 3D chaotic system can be synchronized for calibration. During the calibration process, let

B) Carry out 3D chaos decryption to the image ciphertext E, including:

Set A(E xor Y ^T +E X) Z, where:

X _i =(tnteger(x×K ₁ )modN)

Y _i =(tnteger(x×K ₂ )modM)

Z _i ＝(integer(x×K ₃ )mod256)

In the formula, X _i , Y _i , Z _i are the ith elements of the matrix X, Y, Z, K ₁ , K ₂ , K ₃ are random integers, M, N are the number of rows and columns of the image ciphertext E .

Figure 5 shows a flow chart for image data secure transmission according to a preferred embodiment of the present invention, including: image sender: first obtain image plaintext A from the image file, and then perform 3D chaos encryption on A to obtain a 3D chaos encrypted image Ciphertext E, and compress and encode E to obtain compressed 3D chaotic encrypted ciphertext Z; at the same time, the system performs ECC encryption, and the 3D chaotic encrypted keys x ₀ , y ₀ , z ₀ , K ₁ , K ₂ , K The combined binary number K _3D of ₃ is encrypted to obtain ciphertexts C ₁ and C ₂ ; finally, an encrypted file imgname.en with a key is generated and sent to the image receiver through the network. Image receiver: Receive the encrypted file imgname.en of the image sender through the network, extract the ECC ciphertext C ₁ , C ₂ , and perform ECC decryption on it to obtain x ₀ , y ₀ , z ₀ , K ₁ , K ₂ , K ₃ , extract the compressed 3D chaotic encrypted ciphertext Z, decompress and decode it to obtain the 3D chaotic encrypted ciphertext E, and finally perform 3D chaotic decryption on E to obtain the image plaintext A.

Compared with the prior art, the advantages of the foregoing embodiments of the present invention are:

1. This method combines the advantages of chaotic encryption and ECC encryption, effectively improving the encryption speed, encryption efficiency and security of traditional image encryption methods;

2. This method solves the problem that the encryption of a one-dimensional chaotic system does not strongly destroy the image correlation by constructing a 3D chaotic system;

3. By designing a time verification mechanism in the 3D chaotic encryption system, the method performs time synchronization verification and correction on the 3D chaotic system of the encryption party and the decryption party, effectively preventing the chaotic effect and stability of the chaotic system from changing over time during the operation process decline in sex;

4. During the transmission process of the encrypted image and the 3D chaotic key, the 3D chaotic encryption key is encrypted and transmitted by the ECC encryption algorithm, which effectively improves the security and reliability of the 3D chaotic key transmission and improves the image transmission security.

Other embodiments of the invention will be readily apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any modification, use or adaptation of the present invention, these modifications, uses or adaptations follow the general principles of the present invention and include common knowledge or conventional technical means in the technical field not disclosed in this application . The specification and examples are to be considered exemplary only, with a true scope and spirit of the invention being indicated by the following claims.

It should be understood that the present invention is not limited to the precise constructions which have been described above and shown in the accompanying drawings, and various modifications and changes may be made without departing from the scope thereof. The scope of the invention is limited only by the appended claims.

Claims (1)

1. An encryption method for image data security transmission, is characterized in that, comprises the following steps: Obtain the image plaintext matrix A; Perform 3D chaotic encryption on the image plaintext matrix A to obtain the image ciphertext E; ECC (Elliptic Curves Cryptography, elliptic curve cryptography) encryption is performed on the 3D key encrypted by 3D chaos; The 3D key encrypted by ECC and the image ciphertext E are used to generate an encrypted file for transmission; Wherein, performing 3D chaotic encryption on the image plaintext matrix A includes the following steps: The 3D chaotic system model is established as follows: <mrow><msub><mi>x</mi><mrow><mi>n</mi><mo>+</mo><mn>1</mn></mrow></msub><mo>=</mo><msub><mi>&amp;gamma;x</mi><mi>n</mi></msub><mrow><mo>(</mo><mrow><mn>1</mn><mo>-</mo><msub><mi>x</mi><mi>n</mi></msub></mrow><mo>)</mo></mrow><mo>+</mo><msubsup><mi>&amp;beta;y</mi><mi>n</mi><mn>2</mn></msubsup><msub><mi>x</mi><mi>n</mi></msub><mo>+</mo><msubsup><mi>&amp;alpha;z</mi><mi>n</mi><mn>3</mn></msubsup><mo>+</mo><mi>&amp;delta;</mi><mi>f</mi><mrow><mo>(</mo><mi>&amp;epsiv;</mi><mo>)</mo></mrow></mrow> <mrow><msub><mi>y</mi><mrow><mi>n</mi><mo>+</mo><mn>1</mn></mrow></msub><mo>=</mo><msub><mi>&amp;gamma;x</mi><mi>n</mi></msub><mrow><mo>(</mo><mn>1</mn><mo>-</mo><msub><mi>y</mi><mi>n</mi></msub><mo>)</mo></mrow><mo>+</mo><msubsup><mi>&amp;beta;z</mi><mi>n</mi><mn>2</mn></msubsup><msub><mi>y</mi><mi>n</mi></msub><mo>+</mo><msubsup><mi>&amp;alpha;x</mi><mi>n</mi><mn>3</mn></msubsup></mrow> <mrow><msub><mi>z</mi><mrow><mi>n</mi><mo>+</mo><mn>1</mn></mrow></msub><mo>=</mo><msub><mi>&amp;gamma;z</mi><mi>n</mi></msub><mrow><mo>(</mo><mrow><mn>1</mn><mo>-</mo><msub><mi>z</mi><mi>n</mi></msub></mrow><mo>)</mo></mrow><mo>+</mo><msubsup><mi>&amp;beta;x</mi><mi>n</mi><mn>2</mn></msubsup><msub><mi>z</mi><mi>n</mi></msub><mo>+</mo><msubsup><mi>&amp;alpha;y</mi><mi>n</mi><mn>3</mn></msubsup></mrow> ε＝C ^T x _i Set E=(A xor X ^T +A·Y)xor Z ^T , where: X _i ＝(integer( _xi ×K ₁ )modN) Y _i ＝(integer(y _j ×K ₂ )modM) Z _i ＝(integer(z _k ×K ₃ )mod256) In the formula, X _i , Y _i , Z _i are the ith elements of the matrix X, Y, Z, K ₁ , K ₂ , K ₃ are random integers, M, N are the number of rows and columns of the image plaintext matrix A , x ₀ , y ₀ , z ₀ are randomly generated 3D key seeds, 0<x ₀ <1, 0<y ₀ <1, 0<z ₀ <1, 2.77<γ<3.0, 0<β<0.18 , 0<α<0.02, 0<δ<0.02, x _i , y _j , z _k are random sequences in x, y, z directions output by the 3D chaotic system, 0<i<N, 0<j<M, 0 <k<M×N, ε is the time calibration control quantity, and C is the system time calibration interval control matrix; Wherein, performing ECC encryption on the 3D key encrypted by 3D chaos includes the following steps: Obtain the image receiver's elliptic curve parameters Ep(a, b), base point G and public key K; Set K _3D ＝x ₀ ||y ₀ ||z ₀ ||K ₁ ||K ₂ ||K ₃ , where || is an OR operator, that is, a bitwise OR operation; Execute the BCH encoding algorithm to encode K _3D to point E _3D on Ep(a,b); Generate a random large integer r; Set ciphertext C ₁ =E _3D +rK, ciphertext C ₂ =rG, where rK and rG are elliptic curve scalar multiplication operations; Wherein, generating the encrypted file jointly with the 3D key encrypted by ECC and the image ciphertext E includes the following steps: Create binary files; Convert C ₁ and C ₂ into binary and write them into binary files, and write the ECC ciphertext end flag at the end; Write the image ciphertext E to the binary file in an appended manner; Wherein, performing 3D chaotic encryption on the image plaintext matrix A also includes compressing and encoding the image ciphertext E.