WO2019104455A1

WO2019104455A1 - Encryption/decryption method, encryption/decryption terminal, and double random phase encryption and decryption system

Info

Publication number: WO2019104455A1
Application number: PCT/CN2017/113261
Authority: WO
Inventors: 邹文斌; 庄兆永; 焦述铭; 李霞; 徐晨
Original assignee: 深圳大学
Priority date: 2017-11-28
Filing date: 2017-11-28
Publication date: 2019-06-06

Abstract

The present invention is suitable for use in the technical field of data processing, and provides an encryption method, comprising: generating a hidden key according to a preset cyclic shift value and flip value; using the hidden key to encrypt an original plaintext to obtain an initial ciphertext image; shifting and flipping the initial ciphertext image according to a cyclic shift value and a flip value to obtain a quasi-final ciphertext; inputting the quasi-final ciphertext into a double random phase encryption system to obtain a final ciphertext. In the embodiments of the present invention, a hidden key is generated from a cyclic shift value and a flip value, and said hidden key is used for building an additional encryption layer in an original plaintext and double random phase encryption system; it is impossible for a ciphertext-only attack (COA) to obtain the correct cyclic shift and flip value when attacking a final ciphertext; therefore it is impossible to obtain a hidden key according to a correct cyclic shift and flip value, and thus impossible to decipher a final ciphertext encrypted by means of the embodiments of the present invention; the security of a double random phase encryption system can be improved by means of the embodiments of the present invention.

Description

Add/decrypt method, encryption/decryption terminal and double random phase encryption and decryption system

The invention belongs to the technical field of data processing, and in particular relates to an encryption/decryption method against an ciphertext attack, an encryption/decryption terminal and a dual random phase encryption and decryption system.

Research on optical information security has received increasing attention in the past decade. Optical encryption systems are widely used in information encryption, information authentication and information hiding. In optical security encryption, information is processed optically rather than digitally, so it has the advantages of multi-dimensionality, high parallelism and fast processing speed.

The Double Random Phase Encoding (DRPE) system was the first attempt to encrypt information using an optical encryption system in 1995. The DRPE can be used in the image domain and the Fourier transform domain of the 4f optical lens system, or in the fractional Fourier domain, Fresnel domain. Despite many achievements, DRPE technology still faces some difficulties and challenges, such as the lack of security strength of DRPE systems.

In the past, the academic community actively studied the security vulnerabilities of optical encryption systems, and proposed an attack algorithm to crack the optical encryption system, and then improved its optical encryption system against the weaknesses of the attack scheme. Improved optical encryption systems may be further exploited by new attack methods. This is a repetitive cycle of progress between the new cracking method in the development of secure encryption systems and the new anti-hacking encryption security system. For the DRPE system, there are many attack methods to crack the encryption system. The commonly used attack methods include known plaintext attacks, plaintext attacks, ciphertext attacks, and ciphertext attacks (Ciphertext). Attack methods such as Only Attack, COA). Among these attack methods, the ciphertext attack COA is the most deadly method for the DRPE system. Because the ciphertext attack COA can illegally recover the plaintext from the ciphertext information alone, the DRPE system has serious security vulnerabilities.

Summary of the invention

The technical problem to be solved by the present invention is to provide an encryption/decryption method against an ciphertext attack, an encryption/decryption terminal, and a dual random phase encryption and decryption system, which aims to solve the problem that the ciphertext only attack COA can be separately secreted in the prior art. In the text information, the plaintext is illegally recovered, and the DRPE system has serious security vulnerabilities.

The present invention is implemented in such a manner that an encryption method includes:

Generating a hidden key according to a preset cyclic shift value and a flip value;

Encrypting the original plaintext by using the hidden key to obtain an initial ciphertext picture;

And shifting and flipping the initial ciphertext picture according to the cyclic shift value and the flip value to obtain a quasi-final ciphertext;

The quasi-final ciphertext is input into a double random phase encryption system to obtain a final ciphertext.

Further, the generating the hidden key according to the preset cyclic shift value and the flip value includes:

Generating a key seed according to the cyclic shift value and the inverted value;

The key seed is input to a random number generator to generate the hidden key.

Further, the shifting and flipping the original plaintext by using the hidden key to obtain the initial ciphertext includes:

Binding the original plaintext to obtain the original binary plaintext;

Encrypting the original binary plaintext by using the hidden key to obtain a binary sequence initial ciphertext;

Converting the binary sequence initial ciphertext to the initial ciphertext picture.

Further, the shifting and flipping the initial ciphertext picture according to the cyclic shift value and the flip value to obtain the quasi-final ciphertext includes:

Inserting original location reference information into the initial ciphertext picture to obtain a reference picture;

And shifting the reference picture according to the cyclic shift value, and flipping the shifted reference picture according to the inversion value to obtain the quasi-final ciphertext.

The embodiment of the invention further provides an encryption terminal, including:

a key generating unit, configured to generate a hidden key according to the preset cyclic shift value and the flip value;

The plaintext encryption unit is configured to encrypt the original plaintext by using the hidden key to obtain an initial ciphertext image, and perform shifting and flipping on the initial ciphertext image according to the cyclic shift value and the flip value to obtain a quasi-final secret For example, the quasi-final ciphertext is input into the double random phase encryption system to obtain a final ciphertext.

Further, the plaintext encryption unit is specifically configured to:

Inputting the key seed into a random number generator to generate the hidden key;

Binding the original plaintext to obtain the original binary plaintext;

Converting the binary sequence initial ciphertext into the initial ciphertext picture;

The embodiment of the invention further provides a decryption method, including:

Entering the decryption key and the final ciphertext into the double random phase decryption system to obtain a quasi-final ciphertext;

Performing shifting and flipping the quasi-final ciphertext according to the decryption shift flip information to obtain an initial ciphertext picture;

Generating a hidden key according to the decrypted shift flip information, and decrypting the initial ciphertext picture according to the hidden key to obtain an original plaintext.

Further, the shifting and flipping the quasi-final ciphertext according to the decryption shift flip information, and obtaining the initial ciphertext image comprises:

Calculating a cyclic shift value (x ₀ , y ₀ ) and a flip value f _p according to the original position reference information and the position reference information in the quasi-final ciphertext, and the cyclic shift value (x ₀ , y ₀ ) and Flipping the value f _p as decryption shift flip information;

And shifting the quasi-final ciphertext according to the cyclic shift value (-x ₀ , -y ₀ ) flip value -f _p respectively to obtain the initial ciphertext picture;

And generating a hidden key according to the decryption shift flip information, and decrypting the initial ciphertext image according to the hidden key, to obtain the original plaintext, including:

Generating a key seed according to the cyclic shift value (x ₀ , y ₀ ) and the inverted value f _p , and inputting the key seed into a random number generator to generate the hidden key;

Binding the initial ciphertext picture to obtain a binary sequence initial ciphertext;

Decrypting the initial ciphertext of the binary sequence by using the hidden key to obtain a binary plaintext;

Converting the binary plaintext to obtain the original plaintext.

The embodiment of the invention further provides a decryption end, comprising:

a ciphertext decryption unit, configured to input the decryption key and the final ciphertext into the double random phase decryption system to obtain a quasi-final ciphertext;

An initial decrypting unit, configured to calculate a cyclic shift value (x ₀ , y ₀ ) and a flip value f _p according to the original position reference information and the position reference information in the quasi-final ciphertext, and the cyclic shift value (x) ₀ , y ₀ ) and the inverted value f _{p are} used as decryption shift flip information, and the quasi-final ciphertext is respectively shifted and inverted according to the cyclic shift value (-x ₀ , -y ₀ ) flip value -f _p , respectively. Obtaining the initial ciphertext picture;

a plaintext decryption unit, configured to generate a key seed according to the cyclic shift value (x ₀ , y ₀ ) and a flip value f _p , and input the key seed into a random number generator to generate the hidden key, and The initial ciphertext picture is binary coded to obtain a binary sequence initial ciphertext, and the binary sequence initial ciphertext is decrypted by using the hidden key to obtain a binary plaintext, and the binary plaintext is converted to obtain the original Clear text.

The embodiment of the invention further provides a dual random phase encryption and decryption system against ciphertext attacks, including the encryption terminal and the decryption terminal described above.

Compared with the prior art, the present invention has the beneficial effects that the embodiment of the present invention generates a hidden key according to the cyclic shift value and the inverted value preset by the user, and encrypts the original plaintext by using the hidden key to obtain an initial ciphertext. The image is shifted and inverted according to the preset cyclic shift value and the inverted value to obtain the quasi-final ciphertext, and finally the quasi-final ciphertext is input into the double random phase encryption system DRPE to obtain the final ciphertext. . The embodiment of the present invention generates a hidden key by using a cyclic shift value and a flip value, and constructs an additional encryption layer in the original plaintext and dual random phase encryption system DRPE by using the hidden key, because the ciphertext attack COA is in the pair. In the end, the ciphertext attack cannot obtain the correct cyclic shift and flip value, so the hidden key cannot be obtained according to the correct cyclic shift and the flip value, so that the final ciphertext encrypted by the embodiment of the present invention cannot be cracked. Embodiments of the invention are capable of enhancing the security of a dual random phase encryption system.

DRAWINGS

FIG. 1 is a flowchart of an encryption method according to an embodiment of the present invention;

2 is a schematic structural diagram of an encryption end according to an embodiment of the present invention;

3 is a flowchart of a decryption method according to an embodiment of the present invention;

4 is a schematic structural diagram of a decryption end according to an embodiment of the present invention;

FIG. 5 is a schematic structural diagram of a dual random phase encryption and decryption system against ciphertext attack according to an embodiment of the present invention; FIG.

FIG. 6 is a flowchart of a dual random phase encryption and decryption system against ciphertext attack according to an embodiment of the present invention.

Detailed ways

The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

In the existing COA cracking method, there is a trap in the phase extraction step. That is, although the COA cracking method can crack out the plaintext content, the cyclic shifting and flipping state of the plaintext content of the cracked recovery is incorrect.

Based on this, in the embodiment of the present invention, in the dual random phase encryption and decryption system against ciphertext attack, the cyclic shift value and the flip value input by the user are used to generate hidden key information and utilize the hidden secret. The key constructs an additional layer of encryption between the original plaintext and the dual random phase encryption system DRPE.

FIG. 1 shows an encryption method provided by an embodiment of the present invention, including:

S101. Generate a hidden key according to the preset cyclic shift value and the inverted value.

S102. Encrypt the original plaintext by using the hidden key to obtain an initial ciphertext picture.

S103: Perform shifting and flipping on the initial ciphertext image according to the cyclic shift value and the flip value to obtain a quasi-final ciphertext;

S104. Input the quasi-final ciphertext into the dual random phase encryption system to obtain a final ciphertext.

In the above step S101, the cyclic shift value is represented by (x ₀ , y ₀ ), the inverted value is represented by f _p , and the cyclic shift value (x ₀ , y ₀ ) and the inverted value f _{p are} used as the encrypted information, according to the The encryption information generates a hidden key, and the specific steps include: generating a key seed according to the cyclic shift value (x ₀ , y ₀ ) and the flip value f _p , and inputting the key seed into the random number generator to generate the hidden secret key.

In step S102, the original plaintext is encrypted by using the hidden key generated in step S101. The specific encryption process includes: binary encoding the original plaintext to obtain an original binary plaintext; and using the hidden key to the original binary The plaintext is encrypted to obtain a binary sequence initial ciphertext; the binary sequence initial ciphertext is converted into the initial ciphertext picture. In this step, for the vulnerability of the existing COA attack method to the DRPE crack, that is, cracking the identified loop shift value and the inversion of the incorrect value, the hidden secret generated by the user-preset cyclic shift value and the flip value is generated. The key encrypts the original plaintext, making the original plaintext more secure with this simple encryption operation. Further, converting the initial ciphertext of the binary sequence to the original ciphertext image is to convert the binary number in the initial ciphertext of the binary sequence into a decimal number, and the decimal number is the pixel of the initial ciphertext image.

In S103, the initial ciphertext image obtained by encrypting in step S102 is again flipped and flipped by using the cyclic shift value and the flip value preset by the user. The specific shift flipping process includes: inserting the original in the initial ciphertext image. Position reference information, obtaining a reference picture; shifting the reference picture according to the cyclic shift value, and flipping the shifted reference picture according to the inversion value to obtain the quasi-final ciphertext.

With the encryption method provided in this embodiment, an additional encryption layer is added between the original plaintext and the DRPE system, and the encryption layer is implemented by a loop key generated by the user and a hidden key generated by the inverted value, and the encryption method is implemented by the encryption method. It can enhance the security of the existing DRPE system and solve the problem of ciphertext attacking COA.

FIG. 2 shows an encryption terminal provided by an embodiment of the present invention, including:

The key generation unit 201 is configured to generate a hidden key according to the preset cyclic shift value and the inverted value;

The plaintext encryption unit 202 is configured to encrypt the original plaintext by using the hidden key to obtain an initial ciphertext image, and perform shifting and flipping on the initial ciphertext image according to the cyclic shift value and the flip value to obtain a quasi-final In the ciphertext, the quasi-final ciphertext is input into the double random phase encryption system to obtain the final ciphertext.

Further, the plaintext encryption unit 201 is specifically configured to:

Binding the original plaintext to obtain the original binary plaintext;

For the above encryption method, FIG. 3 shows a decryption method provided by an embodiment of the present invention, including:

S301. Enter a decryption key and a final ciphertext into the dual random phase decryption system to obtain a quasi-final ciphertext;

S302: Perform shifting and flipping the quasi-final ciphertext according to the decryption shift flip information to obtain an initial ciphertext picture;

S303. Generate a hidden key according to the decryption shift flip information, and decrypt the initial ciphertext picture according to the hidden key to obtain an original plaintext.

In step 301, the user uses the encryption key of the DRPE encryption system as the decryption key, inputs the decryption key and the final ciphertext into the dual random phase decryption system, and decrypts the quasi-final ciphertext through the double random phase decryption system.

In step S302, the quasi-final ciphertext includes position reference information, and the original position reference information used in the encryption and the position reference information in the quasi-final ciphertext are calculated to obtain the position distance of the two, and the cyclic shift is determined according to the position distance. a bit value (x ₀ , y ₀ ) and a flip value f _p , the cyclic shift value (x ₀ , y ₀ ) and the inverted value f _{p are} used as decryption shift flip information, and the decryption shift flip information is determined to be required The quasi-final ciphertext shifts the cyclic shift value (-x ₀ , -y ₀ ) and the flip value -f _p according to the cyclic shift value (-x ₀ , -y ₀ ) and the flip value -f _p The quasi-final ciphertext is shifted and flipped to obtain an initial ciphertext picture.

In step S303, the decryption end generates a key seed according to the cyclic shift value (x ₀ , y ₀ ) and the inverted value f _p , and inputs the key seed into a random number generator to generate the hidden key. The initial ciphertext picture is binary coded to obtain a binary sequence initial ciphertext, and the binary sequence initial ciphertext is decrypted by using the hidden key to obtain a binary plaintext, and the binary plaintext is converted to obtain the original plaintext. .

FIG. 4 shows a decryption end according to an embodiment of the present invention, including:

a ciphertext decryption unit 401, configured to input the decryption key and the final ciphertext into the double random phase decryption system to obtain a quasi-final ciphertext;

The initial decryption unit 402 is configured to perform shifting and flipping the quasi-final ciphertext according to the decryption shift flip information to obtain an initial ciphertext picture.

The plaintext decryption unit 403 is configured to generate a hidden key according to the decrypted shift flip information, and decrypt the initial ciphertext image according to the hidden key to obtain an original plaintext.

Further, the initial decryption unit 402 is specifically configured to: calculate a cyclic shift value (x ₀ , y ₀ ) and a flip value f _p according to the original position reference information and the position reference information in the quasi-final ciphertext, in the loop The shift value (x ₀ , y ₀ ) and the flip value f _{p are} used as decryption shift flip information, and the quasi-final ciphertext is respectively inverted according to the cyclic shift value (−x ₀ , −y ₀ )−f _p Shift and flip to get the initial ciphertext picture.

The plaintext decryption unit 403 is specifically configured to: generate a key seed according to the cyclic shift value (x ₀ , y ₀ ) and the inverted value f _p , and input the key seed into a random number generator to generate the hidden key Binding the initial ciphertext picture to obtain a binary sequence initial ciphertext, decrypting the binary sequence initial ciphertext by using the hidden key, obtaining a binary plaintext, and converting the binary plaintext to obtain a The original plain text.

FIG. 5 shows a dual random phase encryption and decryption system against ciphertext attack according to an embodiment of the present invention, including the encryption end shown in FIG. 2 and the decryption end shown in FIG.

In a specific application, an encryption end may correspond to one or more decryption ends, that is, after the encryption end completes encryption of the original plaintext, the encrypted final ciphertext is transmitted to one or more decryption ends, and the decryption end transmits according to the encryption end. The final ciphertext and the encryption key used in the encryption decrypt the final key. In this embodiment, the encryption end and the decryption end perform encryption and decryption in a symmetric manner, that is, when the encryption end uses a random number generator to generate a hidden key, the same random number generator is used to generate a hidden key on the decryption end, and the encryption end will be used. The encryption key used in the final ciphertext input into the DEPR encryption system will be used as the decryption key when the decryption end decrypts the final ciphertext using the DRPE decryption system.

When decrypting the final ciphertext transmitted by the encryption end, the decryption end needs to use the original location reference information used for encryption, the preset cyclic shift value and the flip value of the user, and the encryption key of the encryption end, and the encryption end is used by the decryption end. The encryption key, the original location reference information, the cyclic shift value, and the flip value can complete the decryption of the final ciphertext.

FIG. 6 shows an encryption and decryption process of a dual random phase encryption and decryption system against ciphertext attack provided by an embodiment of the present invention, including:

a. The encryption end performs binary coding on the original plaintext 2DC1 to obtain the original binary plaintext;

b. The encryption end combines the cyclic shift value (x ₀ , y ₀ ) set by the user and the inverted value f _p to generate a key seed;

c. The encryption end inputs the key seed into the random number generator to generate a hidden key;

d. The encryption end encrypts the original binary plaintext by using a hidden key to obtain a binary sequence initial ciphertext;

e, the encryption end converts the initial ciphertext of the binary sequence into the initial ciphertext picture 703D;

f. The encryption end inserts the original position reference information Y into the initial ciphertext picture 703D to obtain a reference picture, and shifts and flips the reference picture according to the cyclic shift value (x ₀ , y ₀ ) and the inverted f _p value set by the user. Obtain the quasi-final ciphertext Y703D;

g. The encryption terminal inputs the quasi-final ciphertext Y703D into the double random phase encryption system DRPE to obtain the final ciphertext;

h, the encryption end transmits the final ciphertext to a specific decryption end in an unsafe environment;

i. The decryption end uses the key of the double random phase encryption system DRPE as the decryption key, and inputs the decryption key and the final ciphertext into the double random phase decryption system to obtain the decrypted quasi-final ciphertext Y703D;

j. The decryption end determines the cyclic shift value according to the calculated position distance according to the original position reference information Y in the decrypted quasi-final ciphertext Y703D, combined with the position distance calculated according to the original position reference information Y inserted during encryption. ₀ , y ₀ ) and flipping the f _p value, the decryption end decrypts the quasi-final ciphertext Y703D according to the loop position (-x ₀ , -y ₀ ) and flips -f _{p to} obtain the initial ciphertext picture 703D;

k. The decryption end performs binary encoding on the initial ciphertext picture 703D to obtain a binary sequence initial ciphertext;

l, the decryption end combines the decrypted cyclic shift value (x ₀ , y ₀ ) and the inverted f _p value to generate a key seed;

m, the decryption end inputs the key seed into the same random number generator as the encryption end to generate a hidden key;

n, the decryption end decrypts the initial ciphertext of the binary sequence according to the hidden key, and obtains the decrypted binary plaintext;

o. The decryption end converts the decrypted binary plaintext into the decrypted plaintext 2DC1.

In the embodiment of the present invention, the cyclic shift and flip state of the plaintext content recovered by the existing ciphertext attack COA crack recovery using the double random phase encryption system DRPE research is usually an incorrect defect, and the cyclic shift and flip are performed. The state is used as a key seed to generate a hidden key to encrypt the plaintext, and an enhanced dual random phase encryption system against the ciphertext attack is proposed, that is, it performs symmetric encryption and then DRPE encryption before DRPE encryption. Because the cyclic shift and flip state of the plaintext obtained by the ciphertext attack COA crack is usually incorrect, the calculated cyclic shift and flip value are also incorrect, so the hidden key is not obtained. The encrypted ciphertext obtained by the embodiment of the invention can be protected from the ciphertext attack COA, and the security of the DRPE encryption system is improved.

The embodiment of the present invention combines symmetric encryption and DRPE encryption, and can be widely applied to information security protection in the fields of military, government affairs, business, finance, and personal privacy.

The above is only the preferred embodiment of the present invention, and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection of the present invention. Within the scope.

Claims

An encryption method, comprising:
Generating a hidden key according to a preset cyclic shift value and a flip value;
Encrypting the original plaintext by using the hidden key to obtain an initial ciphertext picture;
And shifting and flipping the initial ciphertext picture according to the cyclic shift value and the flip value to obtain a quasi-final ciphertext;
The quasi-final ciphertext is input into a double random phase encryption system to obtain a final ciphertext.
The encryption method according to claim 1, wherein the generating the hidden key according to the preset cyclic shift value and the inverted value comprises:
Generating a key seed according to the cyclic shift value and the inverted value;
The key seed is input to a random number generator to generate the hidden key.
The encryption method according to claim 1 or 2, wherein the encrypting the original plaintext by using the hidden key to obtain the initial ciphertext comprises:
Binding the original plaintext to obtain the original binary plaintext;
Encrypting the original binary plaintext by using the hidden key to obtain a binary sequence initial ciphertext;
Converting the binary sequence initial ciphertext to the initial ciphertext picture.
The encryption method according to claim 1, wherein the shifting and flipping the initial ciphertext picture according to the cyclic shift value and the flip value to obtain a quasi-final ciphertext comprises:
Inserting original location reference information into the initial ciphertext picture to obtain a reference picture;
And shifting the reference picture according to the cyclic shift value, and flipping the shifted reference picture according to the inversion value to obtain the quasi-final ciphertext.
An encryption terminal, comprising:
a key generating unit, configured to generate a hidden key according to the preset cyclic shift value and the flip value;
The plaintext encryption unit is configured to encrypt the original plaintext by using the hidden key to obtain an initial ciphertext image, and perform shifting and flipping on the initial ciphertext image according to the cyclic shift value and the flip value to obtain a quasi-final secret For example, the quasi-final ciphertext is input into the double random phase encryption system to obtain a final ciphertext.
The encryption terminal according to claim 5, wherein the plaintext encryption unit is specifically configured to:
Generating a key seed according to the cyclic shift value and the inverted value;
Inputting the key seed into a random number generator to generate the hidden key;
Binding the original plaintext to obtain the original binary plaintext;
Encrypting the original binary plaintext by using the hidden key to obtain a binary sequence initial ciphertext;
Converting the binary sequence initial ciphertext into the initial ciphertext picture;
Inserting original location reference information into the initial ciphertext picture to obtain a reference picture;
And shifting the reference picture according to the cyclic shift value, and flipping the shifted reference picture according to the inversion value to obtain the quasi-final ciphertext.
A decryption method, comprising:
Entering the decryption key and the final ciphertext into the double random phase decryption system to obtain a quasi-final ciphertext;
And translating and decrypting the quasi-final ciphertext according to the decryption shift flip information to obtain an initial ciphertext picture;
Generating a hidden key according to the decrypted shift flip information, and decrypting the initial ciphertext picture according to the hidden key to obtain an original plaintext.
The decryption method according to claim 7, wherein the decrypting the quasi-final ciphertext according to the decryption shift flip information, and obtaining the initial ciphertext image comprises:
Calculating a cyclic shift value (x 0 , y 0 ) and a flip value f p according to the original position reference information and the position reference information in the quasi-final ciphertext, and the cyclic shift value (x 0 , y 0 ) and Flipping the value f p as decryption shift flip information;
And shifting the quasi-final ciphertext according to the cyclic shift value (-x 0 , -y 0 ) flip value -f p respectively to obtain the initial ciphertext picture;
And generating a hidden key according to the decryption shift flip information, and decrypting the initial ciphertext image according to the hidden key, to obtain the original plaintext, including:
Generating a key seed according to the cyclic shift value (x 0 , y 0 ) and the inverted value f p , and inputting the key seed into a random number generator to generate the hidden key;
Binding the initial ciphertext picture to obtain a binary sequence initial ciphertext;
Decrypting the initial ciphertext of the binary sequence by using the hidden key to obtain a binary plaintext;
Converting the binary plaintext to obtain the original plaintext.
A decryption end, comprising:
a ciphertext decryption unit, configured to input the decryption key and the final ciphertext into the double random phase decryption system to obtain a quasi-final ciphertext;
An initial decrypting unit, configured to calculate a cyclic shift value (x 0 , y 0 ) and a flip value f p according to the original position reference information and the position reference information in the quasi-final ciphertext, and the cyclic shift value (x) 0 , y 0 ) and the inverted value f p are used as decryption shift flip information, and the quasi-final ciphertext is respectively shifted and inverted according to the cyclic shift value (-x 0 , -y 0 ) flip value -f p , respectively. Obtaining the initial ciphertext picture;
a plaintext decryption unit, configured to generate a key seed according to the cyclic shift value (x 0 , y 0 ) and a flip value f p , and input the key seed into a random number generator to generate the hidden key, and The initial ciphertext picture is binary coded to obtain a binary sequence initial ciphertext, and the binary sequence initial ciphertext is decrypted by using the hidden key to obtain a binary plaintext, and the binary plaintext is converted to obtain the original Clear text.
A dual random phase encryption and decryption system against ciphertext attack, comprising the encryption end according to claim 5 or 6, and the decryption end according to claim 9.