. , - , () .
, , . , , .. , , . , . , . , . , . , . , , , .. . PIN-.
, -, , , . PIN- (, Personal Identification Number - ). PIN- , , PIN- , . , , PIN-. PIN . PIN- . , PIN- . , . ISO 9564-1 , PIN- - . , , , (, ..). PIN- , 0 9. PIN- , -, , , PIN- , , . PIN- , . , - , PIN- , PIN- . PIN- . PIN- (). PIN- . PIN-. , -. PIN- - PIN-. PIN- , PIN-. PIN- , , , . PIN- , , PIN- . PIN- PIN- . , , , , 1111, 1234, 0987 .., , - , , 15071970 PIN- , (15 1970- ) .. -, , , , , . PIN- . , PIN-. PIN-, PIN- , . -, PIN-, , . , PIN-, - , .
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45.
1. ( , , , single-key).
1.1. ( ):
(infinite-key cipher);
( - Vernam);
().
1.2. ( ):
1.2.1. (permutation, P-);
1.2.2. (, substitution, S-):
( );
( , , , Enigma);
1.2.3. ( 1):
Lucipher ( IBM, );
DES (Data Encryption Standard, );
FEAL-1 (Fast Enciphering Algoritm, );
IDEA/IPES (International Data Encryption Algorithm/
Improved Proposed Encryption Standard, Ascom-Tech AG, );
B-Crypt ( British Telecom, );
28147-89 (); * Skipjack ().
2. ( , public-key):
- DH (Diffie, Hellman);
--e RSA (Rivest, Shamir, Adleman);
- ElGamal.
, (ciphers) (codes). , , . (, , ).
( ) , . , .
3 :
( , );
, , , ;
.
, .
, . . , .
- ( ) . " ", 2 XOR. .
( ). "" , . . , , . , .
, . , (). - ( , , initializing value, IV) . , . , .
, , [4, c. 63]. [4, c. 126 - 128]:
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1. . , 2 . .
2. () . , , . . .
3. . . .
4. .
. :
(transposition, permutation, P-);
(, substitution, S-).
(, , ) . , , , , , .
. Pa , , , - . :
( );
( , , , Enigma).
, . , . , . , , .
. , , - . .
, , ( ). (product cipher). O , , .
[4, c.129-130]:
1. (). () , . , . (, ). DES ECB 28147-89 .
2. . : 2 . . - . - DES CBC.
[4, c. 128]:
1. . ( ) , .
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2. . .
DES (Data Encryption Standard) [1, 5], ISO 8372-87. DES (American National Standards Institute, ANSI) (American Bankers Association, ABA). DES 4 :
ECB (Electronic Codebook) ;
CBC (Cipher Block Chaining) ;
CFB (Cipher Feedback) ;
OFB (Output Feedback) .
28147-89 - [8]. () : , , - .
. ( ) , () . , 2 , . .
28147-89 . , 28147-89 (256- , 32 ) , DES (56- , 16 ) FEAL-1 (64- , 4 ) .
, DES, 28147-89 , 512- . 28147-89 (256- , 512- , 64- ) B-Crypt (56- , 64- ). 28147-89 ( ) .
. 2 . B-Crypt, DES CFB OFB, 28147-89 c .
c
( ) (), - (). . :
, , ( , , );
, , , ;
, .