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, , , .
, , , , . , , , . , , , ( ). .
,
? "" ( )? - ?, , , , ( ). , , - , - , ! .
, , , ( , ;). , - , , , , , . , .
;).
, . .. , . ( ) ! . , , - , - - - . , .
-
, :
(2.1)
k - ; akÎ{0, 1}- ;
aiÎ{0, 1}- ;
- m .
ai, j(x)=1Åa1x1Åa2x2a3x3am-1xm-1amxm, , {ak} , 2m-1. M-.
(2.1) - , , .
- :
- - ;
- , (2.1), j(x) L = 2m-1;
- j() L
M-, .
.
( ) .
, .
, , .
, , . ( [2]).
( ) , : , . , . , . , .
, , , .
k , ;
m , (prev next), ;
( , ) , ;
f(x, ai) , ai x;
ai i- .
( ) :
(3.1)
prev = 0;
i 1 k
{
next = (prev, ai);
ai = f(prev, ai);
prev = next;
}
( ) :
(3.2)
prev = 0;
i 1 k
{
ai = f
-1(prev, ai);
prev = (prev, ai);
}
, ai , , , . , ai, ? , .
, :
(3.3)
prev = 0;
i k 1
{
next = (prev, ai);
ai = f(prev, ai);
prev = next;
}
, :
(3.4)
prev = 0;
i k 1
{
ai = f
-1(prev, ai);
prev = (prev, ai);
}
(3.1) (3.3) , , , . (3.2) (3.4).
, . (3.1) (3.3) , (3.2) (3.4), f 1(x, y), f(x, y).
:
, , [1]:
- , , ;
- .
. , , ( ) . , .
: , , ( ) , ( ). .
P.S.
- 1Åx502Åx607, , .: , . , .
: , .
bdv78@newmail.ru
http://bdv78.newmail.ru
( )
: int unsigned 4 ., :
//
// - (2^11)-1
// fi(x) = 1(+)x^2(+)x^11
unsigned NextMValue(unsigned prev)
{
register unsigned c = 0;
if(prev & (1<<1))
c++;
if(prev & (1<<10))
c++;
return (prev<<1)|(c&1);
}
prev , , .
, :
//
// 32-
// fi(x) = 1(+)x^1(+)x^27(+)x^28(+)x^32
unsigned NextSignature32
(unsigned prev, unsigned newbit)
{
if(prev&(1<<0))
newbit++;
if(prev&(1<<26))
newbit++;
if(prev&(1<<27))
newbit++;
if(prev&(1<<31))
newbit++;
return (prev<<1)|(newbit&1);
}
:
unsigned char * generate_gamma(unsigned char *pw, unsigned pwlen, unsigned gamma_len, unsigned char * gamma = NULL)
{
const
gb_len = 256;
static int
polynomial[] = { 1, 5, 23, 171, 243, 1057, 2047, -1 };
//polynomial[] = { 1, 18, 20, 39, -1 }; // 2^40 - 1
static unsigned char
buf[gb_len+1];
memset(buf, 0, sizeof(buf));
if(pwlen)
for(int i = 0; i < gb_len; i++)
buf[i+1] = pw[i%pwlen];
else
buf[1] = 1;
if(!gamma)
gamma = new unsigned char [gamma_len];
for(int i = 0; i < gamma_len; i++) {
buf[0] = 0;
for(int j = 0; j < 8; j++) {
register unsigned char newbit = 0;
for(int k = 0; polynomial[k] >= 0; k++) {
register unsigned bit = (polynomial[k]+8-j);
if(buf[bit>>3]&(1<<(bit&7)))
newbit++;
}
buf[0] |= (newbit&1)<<(7-j);
}
memmove(buf+1, buf, gb_len);
gamma[i] = buf[0];
}
return gamma;
}
㭪 . ਢ ⥯ 2048, 256 . 256 , ࠧ 㥬 . 筮 ।⥫쭮 ࣭ ⪥, ⮣ 㤥 ॡ ⮫쪮 256 ⪨, ᯮ 樨 . < ⮫>, ⮬ 樨 ᯮ짮 ਬ⨢ ਢ . 㪠 ਬ⨢ ⥯ 40, ண 뫠 ७ ࠢ쭮 ࠡ 楤. ࠢ ᨬ쭠 ᥣ L.
[1] 㪠뢠 ⪨ ਬ -⥫쭮⥩ 樨 , । ᯮ짮 ⥫쭮 , ࠧ騥 㬬 쪨 -⥫쭮⥩.
㤥 ࠡ ⠬, ᨣ 㤥 ࠧ ᥣ .
ᦠ ⥫쭮 ᨣ ᯮ㥬 ⨬ 㭪 crc32 (ਫ 室묨 ⥪⠬):
unsigned crc32tab[] = {
0x00000000, 0x77073096, 0xee0e612c, 0x990951ba,
0x076dc419, 0x706af48f, 0xe963a535, 0x9e6495a3,
0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988,
0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91,
0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de,
0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7,
0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec,
0x14015c4f, 0x63066cd9, 0xfa0f3d63, 0x8d080df5,
0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172,
0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b,
0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940,
0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59,
0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116,
0x21b4f4b5, 0x56b3c423, 0xcfba9599, 0xb8bda50f,
0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924,
0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d,
0x76dc4190, 0x01db7106, 0x98d220bc, 0xefd5102a,
0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433,
0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818,
0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01,
0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e,
0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457,
0x65b0d9c6, 0x12b7e950, 0x8bbeb8ea, 0xfcb9887c,
0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65,
0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2,
0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb,
0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0,
0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9,
0x5005713c, 0x270241aa, 0xbe0b1010, 0xc90c2086,
0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4,
0x59b33d17, 0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad,
0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a,
0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683,
0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8,
0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1,
0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe,
0xf762575d, 0x806567cb, 0x196c3671, 0x6e6b06e7,
0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc,
0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5,
0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252,
0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b,
0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60,
0xdf60efc3, 0xa867df55, 0x316e8eef, 0x4669be79,
0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236,
0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f,
0xc5ba3bbe, 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04,
0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d,
0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a,
0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713,
0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38,
0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21,
0x86d3d2d4, 0xf1d4e242, 0x68ddb3f8, 0x1fda836e,
0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777,
0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c,
0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45,
0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2,
0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db,
0xaed16a4a, 0xd9d65adc, 0x40df0b66, 0x37d83bf0,
0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6,
0xbad03605, 0xcdd70693, 0x54de5729, 0x23d967bf,
0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94,
0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d
};
// polynomial is
// X^32+X^26+X^23+X^22+X^16+X^12+X^11+X^10+X^8+X^7+X^5+X^4+X^2+X^1+X^0
unsigned crc32( unsigned crc, unsigned char *buf, unsigned buflen)
{
for(unsigned i = 0; i < buflen; i++)
crc = crc32tab[(unsigned char)(crc ^ unsigned(buf[i]))] ^ ((crc >> 8) & 0x00ffffff);
return crc;
}
㭪樨 /:
void encrypt(unsigned char * buf, unsigned buflen, unsigned char * gamma)
{
unsigned prev, next;
unsigned char * pgamma;
// 䠧 1
// 室 ⥪
// ⪠ 1 - אַ 室
prev = 0xffffffff;
pgamma = gamma;
for(int i = 0; i < buflen; i++) {
next = crc32(prev, buf+i, 1);
next = crc32(next, pgamma+i, 1); //
buf[i] += prev;
prev = next;
}
// ⪠ 2 - 室
prev = 0xffffffff;
pgamma = gamma+buflen;
for(int i = buflen-1; i >= 0; i--) {
next = crc32(prev, buf+i, 1);
next = crc32(next, pgamma+i, 1); //
buf[i] += prev;
prev = next;
}
// 䠧 2
// ⥪
// ⪠ 3 - אַ 室
prev = 0xffffffff;
pgamma = gamma+(buflen<<1);
for(int i = 0; i < buflen; i++) {
buf[i] += prev;
prev = crc32(prev, buf+i, 1);
prev = crc32(prev, pgamma+i, 1); //
}
// ⪠ 4 - 室
prev = 0xffffffff;
pgamma = gamma+(buflen<<1)+buflen;
for(int i = buflen-1; i >= 0; i--) {
buf[i] += prev;
prev = crc32(prev, buf+i, 1);
prev = crc32(prev, pgamma+i, 1); //
}
}
void decrypt(unsigned char * buf, unsigned buflen, unsigned char * gamma)
{
unsigned prev, next;
unsigned char * pgamma;
// ࠧ⪠ 4 - 室
prev = 0xffffffff;
pgamma = gamma+(buflen<<1)+buflen;
for(int i = buflen-1; i >= 0; i--) {
next = crc32(prev, buf+i, 1);
next = crc32(next, pgamma+i, 1); //
buf[i] -= prev;
prev = next;
}
// ࠧ⪠ 3 - אַ 室
prev = 0xffffffff;
pgamma = gamma+(buflen<<1);
for(int i = 0; i < buflen; i++) {
next = crc32(prev, buf+i, 1);
next = crc32(next, pgamma+i, 1); //
buf[i] -= prev;
prev = next;
}
// ࠧ⪠ 2 - 室
prev = 0xffffffff;
pgamma = gamma+buflen;
for(int i = buflen-1; i >= 0; i--) {
buf[i] -= prev;
prev = crc32(prev, buf+i, 1);
prev = crc32(prev, pgamma+i, 1); //
}
// ࠧ⪠ 1 - אַ 室
prev = 0xffffffff;
pgamma = gamma;
for(int i = 0; i < buflen; i++) {
buf[i] -= prev;
prev = crc32(prev, buf+i, 1);
prev = crc32(prev, pgamma+i, 1); //
}
}
㭪 䠩:
int cryptfile(int encrypt, char *fn, unsigned char *pw, unsigned pwlen)
{
FILE * f = fopen(fn, "r+b");
unsigned char * buf, * gamma;
unsigned buflen;
if(!f)
return -1;
buflen = filelength(f->fd);
buf = new char[buflen];
gamma = generate_gamma(pw, pwlen, buflen<<2);
fread(buf, buflen, 1, f);
if(encrypt)
encrypt(buf, buflen, gamma);
else
decrypt(buf, buflen, gamma);
rewind(f);
fwrite(buf, buflen, 1, f);
memset(buf, 0xff, buflen);
memset(buf, 0, buflen);
memset(gamma, 0xff, buflen<<2);
memset(gamma, 0, buflen<<2);
delete buf;
delete gamma;
fclose(f);
return 0;
}
让 ᮢ ८ࠧ ⠪ ࠧ 䠩. 䠩, 室, ⮬ 砫, । 䠩, ᮢ (୮, ) ⠢ 0.5%. ᦠ 娢 RAR 䠩 solid-娢 ࠧ 䠩 㢥稫 ( ⠪ ;). ਫ ணࠬ ᠬ⥫쭮 ᯥਬ ࠧ 䠩. ࠢ 䠩. ८ࠧ 䠩 ⮬᪨ ࠢ. 쪮 , ᬮ 㤥. , ᮢ襭⢮ 室 ⥪ ᯥਬ .
// 䠠 (3.8)-1
prev = 0;
i k 1
{
next = (prev, ai);
ai = f
-1(prev, ai);
prev = next;
}
// 䠠 (3.7)-1
prev = 0;
i 1 k
{
next = (prev, ai);
ai = f
-1(prev, ai);
prev = next;
}
// 䠠 (3.6)-1
prev = 0;
i k 1
{
ai = f
-1(prev, ai);
prev = (prev, ai);
}
// 䠠 (3.5)-1
prev = 0;
i 1 k
{
ai = f
-1(prev, ai);
prev = (prev, ai);
}
: , , . , , ( ). .
, , .
, - , . f(i, gi, ai), g , ( , ), . . , .
, .
, [1], .
, : , , ( ) , , . .
. , (3.6) (3.8) , (3.5) (3.7) . , , . , (3.6) (3.8) , . , . ( ) . :
//
prev = prev2 = 0;
( )
{
next = (prev, ai);
ai = f(prev, gi, ai);
prev = next;
ai = f(prev2, gi, ai);
prev2 = (prev2, ai);
}
//
prev = prev2 = 0;
( )
{
next2 = (prev2, ai);
ai = f
-1(prev2, gi, ai);
prev2 = next2;
ai = f
-1(prev, gi, ai);
prev = (prev, ai);
}
, . , , , , .
:
(2.2)y(k) Î {0,1} k- {y(k)}, k = 1..l; aiÎ{0,1} j(x); ai(k-1)Î{0,1} i- k-1- .
aj(k) = aj-1(k-1), j = 2..m.
, , . , GF(2). , c(x) l-1, l- . , , 10011 c() = x4ÅxÅ1. y(), q() S(),
c(x) = q(x)y(x) Å S(x), (2.3)
S(), , ,
m = deg y(x), .
C(x) (m- , a1..am), (2.2), S(x), C(x)¹S(x), .
, ? l, , l£2m-1, [2]. n- (l=2m-2), m, 1-1/2m, m>7 . , - m j(). , , .
.
, , . , .
.
. ?
1
// 䠠 (3.5)
prev = 0;
i 1 k
{
next = (prev, ai);
ai = f(prev, ai);
prev = next;
}
// 䠠 (3.6)
prev = 0;
i k 1
{
next = (prev, ai);
ai = f(prev, ai);
prev = next;
}
2
// 䠠 (3.7)
prev = 0;
i 1 k
{
ai = f(prev, ai);
prev = (prev, ai);
}
// 䠠 (3.8)
prev = 0;
i k 1
{
ai = f(prev, ai);
prev = (prev, ai);
}