CN102904710B - Hyper-chaos encryption method for weak password based on quantum cellular neural network - Google Patents

Abstract

The invention relates to a hyper-chaos encryption method for a weak password based on a quantum cellular neural network, which belongs to the field of the information security technology. The method provided by the invention solves the problem that the existing password system is limited by limited key space so that the safety of the system is difficult to guarantee when running into brute-force attacks. The encryption method provided by the invention combines the hyper-chaos characteristic of the quantum cellular neural network with the advantages of human brain identification; the safe password is divided into two parts, wherein one part is translated into the picture form; in terms of an initial value and extremely sensitive characteristics of a control parameter, images are encrypted by using the high complexity of the hyper-chaos system; the other part of secret key is encrypted by using an AES (Advanced Encryption Standard) encryption method; and the two parts form a safe password for encrypting the data. The encryption method provided by the invention has great key space; the ability resisting to brute force attack is obviously strengthened; the calculated quantity in the encryption process is reduced when less password number is used; and the encryption method has the characteristics of high safety and convenience for remembering by a user.

Description

Based on the weak password hyperchaos encryption method of quantum cellular neural

Technical field

The present invention relates to field of information security technology, be specifically related to a kind of weak password hyperchaos encryption method based on quantum cellular neural.

Background technology

Computer and information security issue by deep research more than 50 years.Comprise the Generally Recognized as safe of cryptographic algorithm, calculation element, operating system and network.Wherein cryptographic system is widely used in authentication and data encryption.The mankind remember the limited in one's ability of password and tend to select weak password that is too simple and that can be foreseen.Thus, the leak that weak password is correlated with becomes the safety problem extensively existed.The method solving weak password problem is all being found by global user and enterprise.

According to statistics, the u s company of 2009 86% will access to your password certification and encryption.If weak password is used as a strong encryption or authentication, then the attack that system may be made to be easy to be subject to violence password search.Research shows, user uses simply usually, and the password that can be foreseen is to treat the problem of this complexity of password.Schneier has investigated 34, online user's password of 000 " Myspace ": wherein user's choice for use 8 characters of 65%, and use " password1 ", " abc123 ", " myspace1 ", and " password " this kind of password there are plenty of such people especially.Also have a considerable amount of user that all accounts are all set to same password, or password is write in notepad, or password is recorded in a form, or iterative cycles uses these class methods of Old Password.Horowitz reports neat password being write on Sticky Note and to be attached on computer screen of the user of 15-20%.Another is recorded in password on paper when investigating the user job of discovery 66%, and 58% is recorded in form.

The defect that weak password is correlated with has great impact to World Economics, and the symmetric key cryptography system of existing commercialization is generally DES (data encryption standard) and AES (Advanced Encryption Standard).One is used to the desirable key of the completely random of aes algorithm, a violence is searched and is attacked in the future present or infeasible.But when key is restricted to a less subspace, will there is theatrical change in situation.And actual conditions are, the password that usual keyword is remembered by people, or assailant by crack accordingly, mechanism can obtain.For so very little key subspace, violence is searched will be effective.

Quantum Cellular Automata (Quantum cellular automata, QCA) is a kind of nano level Novel electronic devices, has superelevation integrated level, super low-power consumption and without the lead-in wire advantage such as integrated, is one of electronic component of new generation.Abroad in Recent Years scholar utilizes the mechanism QCA of Cai Schwann Cells neural net to construct the locally coupled network of cell based on Schrodinger equation, i.e. quantum cellular neural (QCNN).Because the quantum between quantum dot interacts, complicated dynamics can be obtained from the polarizability of each cell.

Summary of the invention

The present invention solves existing password system due to the restriction by limited key space, and when being subject to Brute Force and attacking, its fail safe is difficult to guaranteed problem, provides a kind of weak password hyperchaos encryption method based on quantum cellular neural.

Based on the weak password hyperchaos encryption method of quantum cellular neural, the method is realized by following steps:

Step one, designated length be the password of n position as cryptographic object, n is positive integer;

Step 2, n position password selected for step one is split as the short password SP of m position and the strong encryption keys SK of k position, described m and k is positive integer;

Step 3, strong encryption keys SK step 2 split embed in two dimensional image, obtain image strong encryption keys ISK;

Step 4, Discrete Chaotic Map is carried out to the image strong encryption keys ISK that step 3 obtains, and setup control parameter, obtain scramble image S_ISK, and by scramble image S_ISK according to from top to bottom, order from left to right arranges, and obtains scrambling sequence S;

Step 5, selection quantum cellular neural hyperchaotic system, and initialization and controling parameters.Adopt fourth-order Runge-Kutta method to carry out iterative to described quantum cellular neural hyperchaotic system, obtain chaos sequence K;

Step 6, adopt chaos sequence K to carry out DIFFUSION TREATMENT to the scrambling sequence S that step 4 obtains, realize the equalization of scramble image S_ISK, obtain ciphering sequence C, and to ciphering sequence C according to from top to bottom, order from left to right arranges, generation encrypted image C _final;

Step 7, the encrypted image C that the short password SP employing in m position AES encryption method is encrypted afterwards and step 6 generates that step 2 is split _finalmerge, jointly transmit as Crypted password.

Beneficial effect of the present invention: the present invention proposes a kind of weak password hyperchaos encryption method based on quantum cellular neural, the Dominant Facies of the hyperchaos characteristic of quantum cellular neural and human brain pattern recognition combines by this cryptography scheme.Security password is divided into two parts, is wherein partially converted into graphic form, the high complexity of application hyperchaotic system, to the feature of initial value and controling parameters extreme sensitivity, encrypted image, carrys out mental picture by user, is user-friendly to; Another part key adopts traditional password encryption scheme.Two parts form a security password to data encryption jointly.Key space is large, and the ability of opposing brute force attack obviously strengthens; 105 SP combinations are carried out spending very considerable time required for Brute Force.Simple growth SP space just significantly limit assailant to 106, still keeps quite short password simultaneously.Weak password system of the present invention, use less password figure place, greatly reduce the amount of calculation in ciphering process, reach higher lsafety level, it is high that the method for the invention has fail safe, and user remembers feature easily.

Accompanying drawing explanation

Fig. 1 is the encrypting and decrypting of the weak password hyperchaos encryption method based on quantum cellular neural of the present invention and attacks schematic diagram;

Fig. 2 is the encryption flow figure of the weak password hyperchaos encryption method based on quantum cellular neural of the present invention;

Fig. 3 is the cipher round results figure of the weak password hyperchaos encryption method based on quantum cellular neural of the present invention; Wherein scheming A is original image, and figure B is encrypted image, the correct decrypted image of figure C, and figure D is wrong decrypted image.

Embodiment

Embodiment one, composition graphs 1 to Fig. 3 illustrate present embodiment, and based on the weak password hyperchaos encryption method of quantum cellular neural, the method is realized by following steps:

A1, designated length be the password of n as cryptographic object, n is positive integer, and the pattern length of described n is in the reasonable scope (as 105 combinations);

B1, n position password is split as the short password SP of m position and the strong encryption keys SK of k position;

C1, strong encryption keys SK to be embedded in two dimensional image, form image strong encryption keys ISK; Be with the difference of existing encryption technology, user need not be required to remember SK again, and for human brain, memory piece image is easily a lot of more than memory k position character;

D1, Discrete Chaotic Map is carried out to the image strong encryption keys ISK in step C1, and setup control parameter, obtain scramble image S_ISK.By scramble image S_ISK according to from top to bottom, order from left to right arranges, and obtains scrambling sequence S;

E1, selection quantum cellular neural hyperchaotic system, and initialization and controling parameters.Adopt 4 rank Runge-Kutta methods to carry out iterative to this hyperchaotic system, produce chaos sequence K;

F1, carry out DIFFUSION TREATMENT with above chaos sequence to the scrambling sequence S that step D1 generates, as XOR, obtain ciphering sequence C, realize image equilibration, to C sequence according to from top to bottom, order from left to right arranges, and generates encrypted image C _final;

G1, to step B1 produce the short password SP(SP in l position remembered by user), adopt conventional encryption methods be encrypted, as AES encryption algorithm;

H1, encrypted result step F 1 and G1 generated merge, and jointly transmit as Crypted password.

Because this cryptographic algorithm is symmetric cryptography, decrypting process is the inverse process of ciphering process.Decrypted result can be obtained according to the reverse operating of ciphering process.

Use variable element Cat to map in present embodiment step D1, the equation that Cat maps is defined as:

$\left(\begin{array}{c}{x}_{n+1}\\ y_{n+1}\end{array}\right)=A\left(\begin{array}{c}{x}_n\\ y_n\end{array}\right)\mathrm{mod}\left(N\right)=\left[\begin{array}{cc}1& p\\ q& \mathrm{pq}+1\end{array}\right]\left(\begin{array}{c}{x}_n\\ y_n\end{array}\right)\mathrm{mod}\left(N\right)---\left(1\right)$

In formula, suppose that image strong encryption keys ISK is the gray level image of N × N pixel, controling parameters p, q are positive integer, can be set by the user, and are required to meet det (A)=1.

By image strong encryption keys ISK according to equation (1) arrangement, be converted into scramble image S_ISK.

The quantum cell neural network system model that in present embodiment, step e 1 uses is:

$\left\{\begin{array}{c}{\stackrel{.}{P}}_1=-2a_1\sqrt{1-P_1^2}\sin {\mathrm{\φ}}_1\\ {\stackrel{.}{\mathrm{\φ}}}_1=-{\mathrm{\ω}}_1(P_1-P_2)+2a_1\frac{P_1}{\sqrt{1-P_1^2}}\cos {\mathrm{\φ}}_1\\ {\stackrel{.}{P}}_2=-2a_2\sqrt{1-P_2^2}\sin {\mathrm{\φ}}_2\\ {\stackrel{.}{\mathrm{\φ}}}_2=-{\mathrm{\ω}}_2(P_2-P_1)+2a_2\frac{P_2}{\sqrt{1-P_2^2}}\cos {\mathrm{\φ}}_2\end{array}\right.---\left(2\right)$

Wherein, P ₁and P ₂be the polarizability of two Quantum Cellular Automata (QCA), φ ₁and φ ₂be the phase place of two QCA, a1 and a2 is the coefficient be directly proportional to energy between quantum dot in each QCA, ω ₁and ω ₂it is the weighted influence coefficient of the difference of adjacent QCA polarizability.

Work as ω ₁=ω ₂=0.5, a ₁=a ₂when=0.075, system (2) is in hyperchaos state.Parameter a1 and a2, ω ₁and ω ₂also can be chosen by user.

When i-th (i=1,2 ..., (N × N)/4) secondary iteration system (2) quantum cellular neural time, four of generation value { x ₁(i), x ₂(i), x ₃(i), x ₄(i) } for generating chaos sequence .Through type (3) is asked for:

$\left\{\begin{array}{c}{K}_{x_1\left(i\right)}=\mathrm{mod}(\mathrm{round}((\mathrm{abs}\left(x_1\left(i\right)\right)-\mathrm{floor}\left(\mathrm{abs}\left(x_1\left(i\right)\right)\right)){\×10}^{14}+S_{4(i-1)}),N)\\ K_{x_2\left(i\right)}=\mathrm{mod}(\mathrm{round}((\mathrm{abs}\left(x_2\left(i\right)\right)-\mathrm{floor}\left(\mathrm{abs}\left(x_2\left(i\right)\right)\right)){\×10}^{14}+S_{4(i-1)+1}),N)\\ K_{x_3\left(i\right)}=\mathrm{mod}(\mathrm{round}((\mathrm{abs}\left(x_3\left(i\right)\right)-\mathrm{floor}\left(\mathrm{abs}\left(x_3\left(i\right)\right)\right)){\×10}^{14}+S_{4(i-1)+2}),N)\\ K_{x_4\left(i\right)}=\mathrm{mod}(\mathrm{round}((\mathrm{abs}\left(x_4\left(i\right)\right)-\mathrm{floor}\left(\mathrm{abs}\left(x_4\left(i\right)\right)\right)){\×10}^{14}+S_{4(i-1)+3}),N)\end{array}\right.---\left(3\right)$

Image equilibration method in present embodiment in step F 1 adopts scheme shown in formula (4), obtains sequence C

$\left\{\begin{array}{c}{C}_{4(i-1)+1}=\mathrm{bit}\mathrm{xor}(S_{4(i-1)+1},K_{x_1\left(i\right)})\\ C_{4(i-1)+2}=\mathrm{bit}\mathrm{xor}(S_{4(i-1)+2},K_{x_2\left(i\right)})\\ C_{4(i-1)+3}=\mathrm{bit}\mathrm{xor}(S_{4(i-1)+3},K_{x_3\left(i\right)})\\ C_{4i}=\mathrm{bit}\mathrm{xor}(S_{4i},K_{x_4\left(i\right)})\end{array}\right.---\left(4\right)$

Embodiment two, composition graphs 3 illustrate present embodiment, and present embodiment is the embodiment of the weak password hyperchaos encryption method based on quantum cellular neural described in embodiment one:

One, select seven passwords " custABC " as cryptographic object, wherein front four " cust " strong encryption keys SK, rear three " ABC " are as short password SP;

Two, " cust " is embedded in two dimensional image, generate the image strong encryption keys ISK of 128 × 128 pixels;

Three, by chaotic maps equation (1) Suo Shi, setup control parameter p=36, q=3, carries out image scrambling process to image strong encryption keys ISK, obtains scramble image S_ISK.And by scramble image S_ISK according to from top to bottom, order from left to right arranges, and obtains scrambling sequence S;

Four, by hyperchaotic system formula (2) Suo Shi, initialization P ₁(0)=0.5, P ₂(0)=0.999, φ ₁=-20, φ ₂=2.5 and controling parameters ω ₁=ω ₂=0.5, a ₁=a ₂=0.075.Adopt 4 rank Runge-Kutta methods to carry out iterative to this hyperchaotic system, produce chaos sequence K;

Five, carry out equalization processing according to method formula (4) Suo Shi to image, obtain sequence C, to C sequence according to from top to bottom, order from left to right arranges, and generates encrypted image C _final;

Six, AES encryption scheme is used to be encrypted short password " ABC "; By encrypted result and encrypted image C _finalintegrate, by the Crypted password transmission finally obtained.

Cipher round results composition graphs 3, can find out that encryption rear video image scrambling is abundant, cannot reflect any information of original image, cipher round results is good; Image after correct deciphering and original image completely the same.

Claims (4)

1., based on the weak password hyperchaos encryption method of quantum cellular neural, it is characterized in that, the method is realized by following steps:

Step one, designated length be the password of n position as cryptographic object, n is positive integer;

Step 2, n position password selected for step one is split as the short password SP of m position and the strong encryption keys SK of k position, described m and k is positive integer;

Step 3, strong encryption keys SK step 2 split embed in two dimensional image, obtain image strong encryption keys ISK;

Step 4, Discrete Chaotic Map is carried out to the image strong encryption keys ISK that step 3 obtains, and setup control parameter, obtain scramble image S_ISK, and by scramble image S_ISK according to from top to bottom, order from left to right arranges, and obtains scrambling sequence S;

Step 5, selection quantum cellular neural hyperchaotic system, and initialization and controling parameters, adopt fourth-order Runge-Kutta method to carry out iterative to described quantum cellular neural hyperchaotic system, obtain chaos sequence K;

Step 6, adopt chaos sequence K to carry out DIFFUSION TREATMENT to the scrambling sequence S that step 4 obtains, realize the equalization of scramble image S_ISK, obtain ciphering sequence C, and to ciphering sequence C according to from top to bottom, order from left to right arranges, generation encrypted image C _final;

Step 7, the encrypted image C that the short password SP employing in m position AES encryption method is encrypted afterwards and step 6 generates that step 2 is split _finalmerge, jointly transmit as Crypted password.

2. the weak password hyperchaos encryption method based on quantum cellular neural according to claim 1, it is characterized in that, described in step 4, Discrete Chaotic Map is carried out to image strong encryption keys ISK, and setup control parameter, the detailed process obtaining scramble image S_ISK is: adopt variable element Cat to map, the equation definition equation one that described Cat maps is expressed as:

Equation one $\left(\begin{array}{c}{x}_{n+1}\\ y_{n+1}\end{array}\right)=A\left(\begin{array}{c}{x}_n\\ y_n\end{array}\right)\mathrm{mod}\left(N\right)=\left[\begin{array}{cc}1& p\\ q& \mathrm{pq}+1\end{array}\right]\left(\begin{array}{c}{x}_n\\ y_n\end{array}\right)\mathrm{mod}\left(N\right)$

Wherein, setting image strong encryption keys ISK is the gray level image of N × N pixel, and controling parameters is p, q is positive integer, is set by the user, and is required to meet det (A)=1; Image strong encryption keys ISK is arranged according to equation one, is converted into scramble image S_ISK.

3. the weak password hyperchaos encryption method based on quantum cellular neural according to claim 1, it is characterized in that, the quantum cell neural network system model formation one of the employing described in step 5 is expressed as:

Formula one $\left\{\begin{array}{c}{\stackrel{\·}{P}}_1=-2a_1\sqrt{1-{P_1}^2}\sin {\mathrm{\φ}}_1\\ {\stackrel{\·}{\mathrm{\φ}}}_1=-{\mathrm{\ω}}_1(P_1-P_2)+2a_1\frac{P_1}{\sqrt{1-{P_1}^2}}\cos {\mathrm{\φ}}_1\\ {\stackrel{\·}{P}}_2=-2a_2\sqrt{1-{P_2}^2}\sin {\mathrm{\φ}}_2\\ {\stackrel{\·}{\mathrm{\φ}}}_2=-{\mathrm{\ω}}_2(P_2-P_1)+2a_2\frac{P_2}{\sqrt{1-{P_2}^2}}\cos {\mathrm{\φ}}_2\end{array}\right.$

In formula, P ₁and P ₂be respectively the polarizability of two Quantum Cellular Automata, φ ₁and φ ₂be the phase place of two Quantum Cellular Automata, a1 and a2 is the coefficient be directly proportional to energy between quantum dot in each two Quantum Cellular Automata, ω ₁and ω ₂it is the weighted influence coefficient of the difference of adjacent Quantum Cellular Automata polarizability;

Work as ω ₁=ω ₂=0.5, a ₁=a ₂when=0.075, quantum cell neural network system is in hyperchaos state; Wherein, a1 and a2, ω ₁and ω ₂value can be chosen by user;

Adopt formula one carry out i-th (i=1,2 ..., (N × N)/4) secondary iteration time, four values of generation are respectively: { x ₁(i), x ₂(i), x ₃(i), x ₄(i) }, described four values are for generating chaos sequence i=1,2 ..., (N × N)/4; Described generation chaos sequence K is asked for by formula two:

Formula two:

$\left\{\begin{array}{c}{K}_{x_1\left(i\right)}=\mathrm{mod}(\mathrm{round}((\mathrm{abs}\left(x_1\left(i\right)\right)-\mathrm{floor}\left(\mathrm{abs}\left(x_1\left(i\right)\right)\right))\×{10}^{14}+S_{4(i-1)}),N)\\ K_{x_2\left(i\right)}=\mathrm{mod}(\mathrm{round}((\mathrm{abs}\left(x_2\left(i\right)\right)-\mathrm{floor}\left(\mathrm{abs}\left(x_2\left(i\right)\right)\right))\×{10}^{14}+S_{4(i-1)+1}),N)\\ K_{x_3\left(i\right)}=\mathrm{mod}(\mathrm{round}((\mathrm{abs}\left(x_3\left(i\right)\right)-\mathrm{floor}\left(\mathrm{abs}\left(x_3\left(i\right)\right)\right))\×{10}^{14}+S_{4(i-1)+2}),N)\\ K_{x_4\left(i\right)}=\mathrm{mod}(\mathrm{round}((\mathrm{abs}\left(x_4\left(i\right)\right)-\mathrm{floor}\left(\mathrm{abs}\left(x_4\left(i\right)\right)\right))\×{10}^{14}+S_{4(i-1)+3}),N)\end{array}\right..$

4. the weak password hyperchaos encryption method based on quantum cellular neural according to claim 1, is characterized in that, the image equilibration in step 6 adopts formula three to realize, and obtains ciphering sequence C,

$\left\{\begin{array}{c}{C}_{4(i-1)+1}=\mathrm{bit}\mathrm{xor}(S_{4(i-1)+1},K_{x_1\left(i\right)})\\ C_{4(i-1)+2}=\mathrm{bit}\mathrm{xor}(S_{4(i-1)+2},K_{x_2\left(i\right)})\\ C_{4(i-1)+3}=\mathrm{bit}\mathrm{xor}(S_{4(i-1)+3},K_{x_3\left(i\right)})\\ C_{4i}=\mathrm{bit}\mathrm{xor}(S_{4i},K_{x_4\left(i\right)})\end{array}\right.$

Carry out according to from top to bottom to ciphering sequence C, order from left to right arranges, and generates encrypted image.