CN1878059A - Grouping encryption and decryption algorithm - Google Patents

Abstract

The invention discloses sectionalization encipher-decipher algorithm, which is characterized by the following: adopting 10-bit number for clear text and secret text as basic arithmetic unit; adopting 10-subtraction method for deciphering course; making the digital sequence length of obtained 10-bit secret text; reducing the problem of secret text inputting time and operating quantity.

Description

A kind of block encryption and decipherment algorithm

Technical field

The present invention relates to a kind of block encryption and decipherment algorithm, belong to digital anti-counterfeiting and field of information security technology.

Background technology

Cryptographic technique is a science and technology of research encryption and decryption conversion.Generally the file with protection to be encrypted is called expressly, and the file behind the enciphering transformation is called ciphertext.The process that expressly is transformed into ciphertext encrypting, is called deciphering with the ciphertext process expressly that is transformed into.Expressly the mutual conversion with ciphertext is reversible, and only has unique, free from error inverible transform.Transformation rule used when plaintext is encrypted is cryptographic algorithm, and transformation rule used when ciphertext is decrypted is decipherment algorithm, and cryptographic algorithm and decipherment algorithm are referred to as cryptographic algorithm.Usually, cryptographic algorithm and decipherment algorithm all are to carry out under the control of key, in order to increase the diversity of conversion.Used key of cryptographic algorithm (encryption key) and the identical cryptographic algorithm of the used key of decipherment algorithm (decruption key) are called the simple key cipher algorithm.The cryptographic algorithm that encryption key is different with decruption key is called the double-key cipher algorithm.

The simple key cipher algorithm can be divided into stream cipher algorithm and block cipher.The cryptographic algorithm that plaintext is encrypted bit by bit by character (as bit) is a stream cipher algorithm, and plaintext is divided into groups (containing a plurality of characters), and the cryptographic algorithm of encrypting by group is a block cipher.

Block encryption algorithm all is according to binary system at present, encrypts by bit.Announce the Data Encryption Standard of carrying out (DES) as the U.S. in 1977, nineteen ninety China and the IDEA (IDEA) of European scholar's co-present, the Advanced Encryption Standard that is used to replace DES (AES) of U.S.'s release in 2000 etc.

Binary block encryption algorithm derives from and serves the computer and the modern digital communication of the minimum unit binary digit (bit) of information representation and processing.For the purpose of the convenience of information conversion; block cipher inside all be divided into about (A, B) two parts; transformation results with the A part comes mould two to add the B part, and the transformation results mould two with the B part adds the A part again, and so loop iteration reaches the purpose of encipherment protection information.So block length must be 2 times of minimum unit, in the time of discontented 2 times, filling information makes it reach 2 times.Minimum unit is the needs that binary digit had both met Computer Processing and digital communication, with minimum filling information amount, reaches the highest charging efficiency again.

But some special occasions, the bill Serial No. (expressly) that shows as 10 system digital displays, after it was encrypted with the binary packet cryptographic algorithm, encrypted result was transformed into the Serial No. (ciphertext) of 10 systems again, and the 10 system ciphertext Serial No. length of this moment are than expressly long.If when by dialing ciphertext being imported into authentication center and verifies, elongated time and the operational ton called of making of ciphertext length increases.For example telephone code is false proof, and after with binary system encryption algorithm plain code being encrypted usually, its result (security code and ciphertext) is longer than plain code (expressly), when the consumer calls the true and false of security code inquiry commodity, has increased time and operational ton equally.

Summary of the invention

In order to solve in the field of information security technology existing cryptographic algorithm technology 10 system numbers are encrypted the back ciphertext than expressly long, when use is carried out the ciphertext checking as means such as phones, increase the time of ciphertext input and the problem of operational ton, the invention provides a kind of block encryption and decipherment algorithm.This block encryption algorithm is finished the encryption to 10 system Serial No.s.When expressly 10 system Serial No.s are block length, or block length equals expressly 10 system Serial No. length, and the length that the length of encrypted result equals to divide into groups adopts corresponding decipherment algorithm that ciphertext is decrypted.

For achieving the above object, the input plaintext and the key of this cryptographic algorithm are 10 system numbers, each function in the algorithm is a basic processing unit with 10 system numerals, modular arithmetic with mould 10 add, mould 10 subtracts, or mould 100 adds, mould 100 is kept to basic operation, and such processing makes this algorithm different with the various block ciphers that occurred.

Cryptographic algorithm of the present invention comprises cryptographic algorithm and decipherment algorithm.The step of cryptographic algorithm and decipherment algorithm is basic identical.

One aspect of the present invention relates to a kind of block encryption algorithm, to expressly encrypting, generates encrypted ciphertext, and this block encryption algorithm comprises that step is as follows:

1) to the plaintext P computing of dividing into groups;

2) encryption cycle iterative computation;

3) evolution and export ciphertext,

Wherein 2) the encryption cycle iterative computation comprises again:

A, digital extended computing;

The hybrid operation of b, key and variable;

C, nonlinear transformation computing;

D, information are covered computing;

E, assignment operation again;

A ring shift right computing of the key of f, block encryption algorithm,

Expressly P is one group of 10 system numeral P ₁, P ₂..., P _i..., P _m, 0≤i≤m, and digital Pi take off row a, b a kind of codomain,

a、0≤P _i≤9

b、0≤P _i≤99

Key K is one group of 10 system numeral K ₁, K ₂..., K _i..., K _m, 0≤i≤m, and digital K _iGet P _iCodomain, each function in the algorithm is a basic processing unit with 10 system numerals, wherein the modular arithmetic in the hybrid operation of b, key and variable is that mould 10 adds computing or mould 100 adds computing, the modular arithmetic that d, information are covered in the computing is that mould 10 adds computing or mould 100 adds computing, generates 10 system ciphertexts of a group encryption.

The present invention relates to a kind of packet deciphering algorithm on the other hand, and ciphertext is decrypted, and generates the plaintext of deciphering, and this packet deciphering algorithm comprises that step is as follows:

1) to the ciphertext C computing of dividing into groups;

2) decryption rounds iterative computation;

3) evolution and output plaintext,

Wherein 2) the decryption rounds iterative computation comprises:

A, digital extended computing;

The hybrid operation of b, key and variable;

C, nonlinear transformation computing;

D, information are covered computing;

E, assignment operation again;

F, a ring shift left computing of key,

Input ciphertext C is one group of 10 system numeral C ₁, C ₂..., C _i..., C _m, 0≤i≤m, and digital C _iCan only take off a kind of codomain of row a, b,

a、0≤C _i≤9

b、0≤C _i≤99

Key K is one group of 10 system numeral K ₁, K ₂..., K _i..., K _m, 0≤i≤m, and digital K _iGet P _iCodomain, each function in the algorithm is a basic processing unit with 10 system numerals, wherein the modular arithmetic in the hybrid operation of b, key and variable is that mould 10 adds computing or mould 100 adds computing, the modular arithmetic that d, information are covered in the computing is that mould 10 subtracts computing or mould 100 subtracts computing, generates the 10 systems plaintext of one group of deciphering.

Beneficial effect: adopt this method in field of information security technology, 10 system numbers to be encrypted back ciphertext Serial No. length with expressly the same long, when use is carried out the ciphertext checking as means such as phones, reduce ciphertext and confirmed the time and the operational ton of input, and adopted corresponding decipherment algorithm to be decrypted.

Description of drawings

Fig. 1 is enciphering and deciphering algorithm schematic diagram of the present invention;

Fig. 2 is cryptographic algorithm Mathematical Modeling schematic diagram of the present invention;

Fig. 3 is decipherment algorithm Mathematical Modeling schematic diagram of the present invention.

Embodiment

The invention will be further described below in conjunction with the drawings and specific embodiments, but not as a limitation of the invention, and cryptographic algorithm of the present invention comprises cryptographic algorithm and decipherment algorithm.The structure of cryptographic algorithm and decipherment algorithm is basic identical.

It all is earlier 10 system number conversions to be become 2 system numbers that the bill Serial No. (expressly) that in the prior art 10 system digital displays is shown is encrypted, after encrypting algorithm for encryption with binary system afterwards, encrypted result is transformed into the Serial No. (ciphertext) of 10 systems again, the 10 system ciphertext Serial No. length of this moment are than expressly long, if when ciphertext being imported into authentication center and verifies by dialing, elongated time and the operational ton called of making of ciphertext length increases, as shown in Figure 1, and each function in the algorithm of the present invention is a basic processing unit with 10 system numerals, modular arithmetic directly adopts mould 10 to add or mould 100 adds the cryptographic algorithm of computing, can solve 10 system ciphertext Serial No. length than expressly long problem, the modular arithmetic of corresponding steps adopts mould 10 to subtract or mould 100 subtracts computing during deciphering.

Embodiment 1

In field of information security technology, the bill Serial No. (expressly) that 10 system digital displays show is made as P here, to the concrete operation process of this block encryption algorithm expressly as shown in Figure 2, comprise the computing of dividing into groups to plaintext P, the encryption cycle iterative computation, evolution and output ciphertext etc., the encryption cycle iterative computation comprises 6 sub-calculating processes, it is respectively the digital extended computing, the hybrid operation of key and variable, the nonlinear transformation computing, information is covered computing, a ring shift right computing of assignment operation and key again, above calculating process all is a prior art, and different is that plaintext P is one group of 10 system numeral P in the present embodiment ₁, P ₂..., P _i..., P _m, 0≤i≤m, and digital Pi take off row a, b a kind of codomain,

a、0≤P _i≤9

b、0≤P _i≤99

Key K is one group of 10 system numeral K ₁, K ₂..., K _i..., K _m, 0≤i≤m, and digital K _iGet P _iCodomain, each function in the algorithm is a basic processing unit with 10 system numerals, modular arithmetic in the hybrid operation of sub-computing key and variable is that mould 10 adds computing or mould 100 adds computing, and the modular arithmetic that sub-computing information is covered in the computing is that mould 10 adds computing or mould 100 adds computing.

The mathematical description of this cryptographic algorithm is specially:

1) to the plaintext P computing of dividing into groups

The part that plaintext P is divided into two equal in length: first half and latter half, first half are P ₁, P ₂..., P _i..., P _s, latter half is P _S+1, P _S+2..., P _j, P _m, m equals 2S; If m is not an even number, then in plaintext, increase a P _iOr increase a P _j, make m become even number, 2 multiples of S.

2) encryption cycle iterative computation

This encryption cycle iterative computation comprises one group of calculating process, and the loop iteration number of times can be set, and in loop iteration, its input is the result of cycle calculations last time, and the input of establishing the e time cycle calculations is X ^e, key is K ^e, output is Z ^e, their component is respectively X ₁ ^e, X ₂ ^e..., X _m ^e, K ₁ ^e, K ₂ ^e..., K _m ^e, Z ₁ ^e, Z ₂ ^e..., Z _s ^e, 0≤e≤n, the input X of cycle calculations first ¹Be plaintext P, X ₁ ¹, X ₂ ¹..., X _m ¹Equal P respectively ₁, P ₂..., P _m, cryptographic algorithm is the key K of cycle calculations first ¹Be key K, K ₁ ¹, K ₂ ¹..., K _i ¹..., K _m ¹Equal K respectively ₁, K ₂..., K _m

The calculating process that the encryption cycle iterative computation comprises:

A, digital extended computing: with X _S+1 ^e, X _S+2 ^e... X _m ^eS variable expands to S to variable altogether, and operation rule is: establish total S to X _u ^e, X _w ^eVariable, u and w difference value S+1, S+2 ..., m each 1 time, and require in one group of variable, $X_u^e{\≠X}_w^e;$

The hybrid operation of b, key and variable: key and X _u ^eAnd X _w ^eThe modular arithmetic of being undertaken by following (1), (2) formula is that mould 10 adds (or mould 100 adds) computing,

$G_u^e=X_u^e\⊕K_h^e---\left(1\right)$

$Q_u^e=X_w^e\⊕K_w^e---\left(2\right)$

Wherein if 0≤P _i≤ 9, then "  " concrete expression is added row operation by mould 10; 0≤P _i≤ 99, then "  " concrete expression adds computing by mould 100, h value 1,2 ..., S each 1 time, u, w value S+1, S+2 ..., m each 1 time;

Below the same P of codomain of each variable _i, the value of subscript h, u, w requires, the computational methods of "  " are with this subprocess,

C, nonlinear transformation computing: establish and have function f _h, this sub-computing is carried out computing by following (3) formula,

$Y_u^e=f_h(G_u^e,Q_u^e),---\left(3\right)$

D, information are covered computing: the modular arithmetic of being undertaken by following (4) formula is that mould 10 adds (or mould 100 adds) computing,

$Z_h^e=X_h^e{\⊕Y}_u^e---\left(4\right)$

E, assignment operation again: undertaken by following (5), (6) formula;

$X_h^{e+1}=X_u^e,---\left(5\right)$

$X_u^{e+1}=Z_h^e---\left(6\right)$

F, a ring shift right computing of key: undertaken by following (7), (8) formula;

$K_{i+1}^{e+1}=K_i^e,i=1,,\·\·\·\·\·\·,m-1---\left(7\right)$

$K_1^{e+1}=K_m^e---\left(8\right)$

3) evolution and output ciphertext: after loop iteration calculated and finishes, after front and back two parts place-exchange of its result, assignment was given ciphertext C, and computations finishes, that is: after loop iteration calculating is finished n time, obtain m X _i ^N+1, with this m X _i ^N+1The exchange of front and back two parts, carry out (9), (10) formula computing.

$C_h=X_u^{e+1},---\left(9\right)$

$C_u=X_h^{e+1}---\left(10\right)$

Adopt this method 10 system numbers being encrypted back ciphertext Serial No. length with expressly the same long, as plaintext Serial No. length is 9, adopting the ciphertext Serial No. length after this method is encrypted also is 9, when the consumer calls security code and is the true and false of cryptogram search commodity, only need dial 9 10 system numerals gets final product, employing prior art then ciphertext Serial No. length is 11, adopts this method to reduce consumer's time and operational ton.

Embodiment 2

Present embodiment is that the ciphertext of output among the corresponding embodiment 1 is decrypted computing, the concrete operation process of decipherment algorithm as shown in Figure 3, comprise ciphertext C is divided into groups computing, decryption rounds iterative computation, evolution and output expressly etc., the decryption rounds iterative computation comprises 6 sub-calculating processes, the hybrid operation, nonlinear transformation computing, the information that are digital extended computing, key and variable are respectively covered computing, an assignment and a ring shift left computing of key again, and above calculating process all is

Prior art.

Corresponding with embodiment 1 cryptographic algorithm, the input ciphertext C of decipherment algorithm is one group of 10 system numeral C ₁, C ₂..., C _i..., C _m, 0≤i≤m, and digital C _iCan only take off a kind of codomain of row a, b,

a、0≤C _i≤9

b、0≤C _i≤99

The key K of decipherment algorithm is one group of 10 system numeral K ₁, K ₂..., K _i..., K _m, 0≤i≤m, and digital K _iGet P _iCodomain, each function in the algorithm is a basic processing unit with 10 system numerals, modular arithmetic in the hybrid operation that sub-computing b, key and variable carry out is that mould 10 adds computing or mould 100 adds computing, sub-computing d, uses information to cover that modular arithmetic in the computing subtracts computing as mould 10 or mould 100 subtracts computing.

The mathematical description of this decipherment algorithm is specially:

1) to the ciphertext C computing of dividing into groups: the part that ciphertext C is divided into two equal in length: first half and latter half, first half are C ₁, C ₂..., C _i..., C _s, latter half is C _S+1, C _S+2..., C _i..., C _m, m equals 2S;

2) decryption rounds iterative computation:

This decryption rounds iterative computation comprises one group of calculating process, and the loop iteration number of times can be set, and in loop iteration, its input is the result of cycle calculations last time, and the input of establishing the e time cycle calculations is X ^e, key is K ^e, output is Z ^e, their component is respectively X ₁ ^e, X ₂ ^e..., X _m ^e, K ₁ ^e, K ₂ ^e..., K _m ^e, Z ₁ ^e, Z ₂ ^e..., Z _s ^e, 0≤e≤n, the input X of cycle calculations first ¹Be ciphertext C, X ₁ ¹, X ₂ ¹..., X _m ¹Equal C respectively ₁, C ₂..., C _m, the key K of cycle calculations first ¹Be n ring shift right of key K, i.e. K ¹K for cryptographic algorithm ⁿ

The calculating process that the decryption rounds iterative computation comprises:

A, digital extended computing: with X _S+1 ^e, X _S+2 ^e... X _m ^eS variable expands to S to variable altogether, and operation rule is: establish total S to X _u ^e, X _w ^eVariable, u and w difference value S+1, S+2 ..., m each 1 time, and require in one group of variable, $X_u^e{\≠X}_w^e;$

The hybrid operation of b, key and variable: key and X _u ^eAnd X _w ^eThe modular arithmetic of being undertaken by following (11), (12) formula is that mould 10 adds (or mould 100 adds) computing;

$G_u^e=X_u^e{\⊕K}_h^e---\left(11\right)$

$Q_u^e=X_w^e\⊕K_w^e---\left(12\right)$

C, nonlinear transformation computing: the function f of using cryptographic algorithm _h, this sub-computing is carried out computing by following (13) formula;

$Y_u^e=f_h(G_u^e,Q_u^e),---\left(13\right)$

D, information are covered computing: the modular arithmetic of this sub-computing is that mould 10 subtracts or mould 100 subtracts computing, carries out computing by following (14) formula,

Wherein if 0≤C _i≤ 9, then "  " specifically represents to subtract by mould 10 and carries out computing; 0≤C _i≤ 99, and then " ,, specifically represent to subtract and carry out computing by mould 100;

E, assignment operation again: this sub-computing is undertaken by following (15), (16) formula;

$X_h^{e+1}=X_u^e,---\left(15\right)$

$X_u^{e+1}=Z_h^e---\left(16\right)$

F, a ring shift left computing of key: this sub-computing is carried out ring shift left by following (17), (18) formula;

$K_i^{e+1}=K_{i+1}^e,i=1,,\·\·\·\·\·\·,m-1---\left(17\right)$

$K_m^{e+1}=K_1^e---\left(18\right)$

3) evolution and output are expressly: after loop iteration calculated and finishes, after front and back two parts place-exchange of its result, assignment was to plaintext P, and deciphering is calculated and finished, that is: after loop iteration calculating is finished n time, obtain m X _i ^N+1, with this m X _i ^N+1The exchange of front and back two parts, carry out (19), (20) computing.

$P_h=X_u^{e+1},---\left(19\right)$

$P_u=X_h^{e+1}---\left(20\right)$

It is that ciphertext is decrypted to the security code of consumer's input among the embodiment 1 that the computer of authentication center adopts this method.

Be the source code of whole encrypting and decrypting algorithm below:

The constant (beginning) of // generation or checking security code

Const bcs=289342928; The base sign indicating number of // security code conversion

bs1：array[0..7]of?byte＝(101，21，93，235，86，206，125，85)；

const?la0：array[0..9，0..9]of?byte

＝((9，3，8，0，5，4，7，2，1，6)，

(2，6，1，3，8，7，0，5，4，9)，

(4，8，3，5，0，9，2，7，6，1)，

(5，9，4，6，1，0，3，8，7，2)，

(8，2，7，9，4，3，6，1，0，5)，

(6，0，5，7，2，1，4，9，8，3)，

(3，7，2，4，9，8，1，6，5，0)，

(1，5，0，2，7，6，9，4，3，8)，

(0，4，9，1，6，5，8，3，2，7)，

(7，1，6，8，3，2，5，0，9，4))；

la1：array[0..9，0..9]of?byte

＝((2，5，4，3，7，1，8，9，0，6)，

(3，6，5，4，8，2，9，0，1，7)，

(4，7，6，5，9，3，0，1，2，8)，

(9，2，1，0，4，8，5，6，7，3)，

(1，4，3，2，6，0，7，8，9，5)，

(8，1，0，9，3，7，4，5，6，2)，

(5，8，7，6，0，4，1，2，3，9)，

(0，3，2，1，5，9，6，7，8，4)，

(6，9，8，7，1，5，2，3，4，0)，

(7，0，9，8，2，6，3，4，5，1))；

la2：array[0..9，0..9]of?byte

＝((8，0，9，4，7，6，3，5，1，2)，

(1，3，2，7，0，9，6，8，4，5)，

(5，7，6，1，4，3，0，2，8，9)，

(3，5，4，9，2，1，8，0，6，7)，

(9，1，0，5，8，7，4，6，2，3)，

(4，6，5，0，3，2，9，1，7，8)，

(7，9，8，3，6，5，2，4，0，1)，

(2，4，3，8，1，0，7，9，5，6)，

(6，8，7，2，5，4，1，3，9，0)，

(0，2，1，6，9，8，5，7，3，4))；

la3：array[0..9，0..9]of?byte

＝((5，8，2，6，3，4，9，1，0，7)，

(0，3，7，1，8，9，4，6，5，2)，

(9，2，6，0，7，8，3，5，4，1)，

(1，4，8，2，9，0，5，7，6，3)，

(4，7，1，5，2，3，8，0，9，6)，

(8，1，5，9，6，7，2，4，3，0)，

(7，0，4，8，5，6，1，3，2，9)，

(2，5，9，3，0，1，6，8，7，4)，

(3，6，0，4，1，2，7，9，8，5)，

(6，9，3，7，4，5，0，2，1，8))；

la4：array[0..9，0..9]of?byte

＝((6，2，8，9，5，1，0，3，7，4)，

(3，9，5，6，2，8，7，0，4，1)，

(7，3，9，0，6，2，1，4，8，5)，

(0，6，2，3，9，5，4，7，1，8)，

(5，1，7，8，4，0，9，2，6，3)，

(9，5，1，2，8，4，3，6，0，7)，

(4，0，6，7，3，9，8，1，5，2)，

(1，7，3，4，0，6，5，8，2，9)，

(2，8，4，5，1，7，6，9，3，0)，

(8，4，0，1，7，3，2，5，9，6))；

Cv1=4; Half of // block length is since 0 note

Cv21=2*cv1+1; // block length is since 0 note

ks：array[0..9]of?byte＝(0，1，2，3，4，5，6，7，8，9)；

cv：array[0..4，0..1]of?byte＝((7，9)，(5，8)，(9，5)，(6，7)，(8，6))；

lps＝6；

//

var

zs，zt，k，kkt，C，P：array[0..9]of?byte；

sss：integer；

procedure?encrypt；

var

i，lp，t1，t2，Xu，Xw，Gu，Qu：integer；

X，Yu，Zh；array[0..9]of?byte；

begin

// encrypt and the all-key conversion

For i:=0 to cv21 do X[i] :=zs[i]; //zs preserves 10 system enciphered datas

for?lp：＝0?to?lps?do

begin

5 Latin tables are got in for i:=0 to cv1 do//circulation

begin

// get dominant vector, look into the Latin table

t1：＝cv[i，0]；

t2：＝cv[i，1]；

Xu：＝X[t1]；

Xw：＝X[t2]；

// key mixes with variable

Gu:=(Xu+k[i]) mod 10; // mould 10 adds

Qu：＝(Xw+k[i+cv1+1])mod?10；

case?i?of

0：Yu[i]：＝la0[Gu，Qu]；

1：Yu[i]：＝la1[Gu，Qu]；

2：Yu[i]：＝la2[Gu，Qu]；

3：Yu[i]：＝la3[Gu，Qu]；

4：Yu[i]：＝la4[Gu，Qu]；

end；

Zh[i] :=(Yu[i]+X[i]) mod 10; // mould 10 adds

end；

for?i：＝0?to?cv1?do?X[i]：＝X[i+cv1+1]；

for?i：＝0?to?cv1?do?X[i+cv1+1]：＝Zh[i]；

// key moves to left

for?i：＝0?to(cv21-1)do?kkt[i+1]：＝k[i]；

kkt[0]：＝k[cv21]；

for?i：＝0?to(cv21)do?k[i]：＝kkt[i]；

end；

// exchange

for?i：＝0?to?cv1?do?C[i]：＝X[cv1+1+i]；

for?i：＝0?to?cv1?do?C[cv1+1+i]：＝X[i]；end；procedure?dencrypt；var

i，lp，t1，t2，Xu，Xw，Gu，Qu：integer；

X，Yu，Zh：array[0..9]of?byte；begin

// deciphering

For i:=0 to cv21 do X[i] :=C[i]; //C preserves 10 system ciphertexts

for?lp：＝0?to?lps?do

begin

// key moves to right

for?i：＝1?to(cv21)do?kkt[i-1]：＝k[i]；

kkt[cv21]：＝k[0]；

for?i：＝0?to(cv21)do?k[i]：＝kkt[i]；

for?i：＝0?to?cv1?do

begin

// get dominant vector, look into the Latin table

t1：＝cv[i，0]；

t2：＝cv[i，1]；

Xu：＝X[t1]；

Xw：＝X[t2]；

Gu:=(Xu+k[i]) mod 10; // mould 10 adds

Qu：＝(Xw+k[i+cv1+1])mod?10；

case?i?of

0：Yu[i]：＝la0[Gu，Qu]；

1：Yu[i]：＝la1[Gu，Qu]；

2：Yu[i]：＝la2[Gu，Qu]；

3：Yu[i]：＝la3[Gu，Qu]；

4：Yu[i]：＝la4[Gu，Qu]；

end；

if?X[i]＞＝Yu[i]then?Zh[i]：＝X[i]-Yu[i]

Else Zh[i] :=10+X[i]-Yu[i]; // mould 10 subtracts

end；

for?i：＝0?to?cv1?do?X[i]：＝X[i+cv1+1]；

for?i：＝0?to?cv1?do?X[i+cv1+1]：＝Zh[i]；

end；

for?i：＝0?to?cv1?do?P[i]：＝X[cv1+1+i]；

For i:=0 to cv1 do P[cv1+1+i] :=X[i]; //P preserves 10 system decrypted results

end；

Above, with reference to each accompanying drawing, several typical embodiment of the present invention are described in detail, so that make the present invention become clearer, and should not think that the present invention only only limits to the above embodiments.Those skilled in the art by the inspiration of the various embodiments described above, is not difficult the present invention is made various improvement, change or replacement, thereby these improvement, change or replacement, should not think to have broken away from design of the present invention, or claims institute restricted portion.

Claims (2)

1, a kind of block encryption algorithm to expressly encrypting, generates encrypted ciphertext, and described block encryption algorithm comprises that step is as follows:

1) to the plaintext P computing of dividing into groups;

2) encryption cycle iterative computation;

3) evolution and output ciphertext;

Described step 2) the encryption cycle iterative computation comprises:

A, digital extended computing;

The hybrid operation of b, key and variable;

C, nonlinear transformation computing;

D, information are covered computing;

E, assignment operation again;

F, a ring shift right computing of key;

It is characterized in that described plaintext P is one group of 10 system numeral P ₁, P ₂..., P _i..., P _m, 0≤i≤m, and digital Pi take off row a, b a kind of codomain,

a、0≤P _i≤9

b、0≤P _i≤99

Key K is one group of 10 system numeral K ₁, K ₂..., K _i..., K _m, 0≤i≤m, and digital K _iGet P _iCodomain, each function in the algorithm is a basic processing unit with 10 system numerals; Modular arithmetic in the hybrid operation of described key and variable is that mould 10 adds computing or mould 100 adds computing, and the modular arithmetic that described information is covered in the computing is that mould 10 adds computing or mould 100 adds computing, generates 10 system ciphertexts of a group encryption.

2, a kind of packet deciphering algorithm is decrypted ciphertext, generates the plaintext of deciphering, and described packet deciphering algorithm comprises that step is as follows:

1) to the ciphertext C computing of dividing into groups;

2) decryption rounds iterative computation;

3) evolution and output plaintext;

Described step 2) the decryption rounds iterative computation comprises:

A, digital extended computing;

The hybrid operation of b, key and variable;

C, nonlinear transformation computing;

D, information are covered computing;

E, assignment operation again;

F, a ring shift left computing of key;

It is characterized in that described input ciphertext C is one group of 10 system numeral C ₁, C ₂..., C _i..., C _m, 0≤i≤m, and digital C _iCan only take off a kind of codomain of row a, b,

a、0≤C _i≤9

b、0≤C _i≤99

Key K is one group of 10 system numeral K ₁, K ₂..., K _i..., K _m, 0≤i≤m, and digital K _iGet P _iCodomain, each function in the algorithm is a basic processing unit with 10 system numerals, modular arithmetic in the hybrid operation of described key and variable is that mould 10 adds computing or mould 100 adds computing, the modular arithmetic that described information is covered in the computing is that mould 10 subtracts computing or mould 100 subtracts computing, generates the 10 systems plaintext of one group of deciphering.

Images