ru.algorithms

 
 - RU.ALGORITHMS ----------------------------------------------------------------
 From : OLS                                  2:5020/400     21 Dec 2001  10:27:50
 To : Andrei Romazanov
 Subject : Re: shifroval'ni algoritm
 -------------------------------------------------------------------------------- 
 

 > ne podskazhet kto-nibud' shifroval'ni algoritm, kotori prosto
 > implementirovalsja v C i v Delphi. Objazatel'noje uslovie, kotoroje
 > zatrudnjaet zadachu:  na vihode dolzhna bit' chisto cifrovaja
 > posledovatel'nost.
 >
 
 Proshe vsego realizuetsa algorithm TEA
 -----------------------
 type   TTEABlock=array[0..1] of longword;
          TTEAKey=array[0..3] of longword;
 
 const TEADelta=$9E3779B9;
 
 procedure EnTEARound(var b:TTEABlock; const k:TTEAKey);
 var sum,round:longword;
 begin
 for round:=0 to 31 do
     begin
     sum:=sum+TEAdelta;
     b[0]:=b[0]+ (((b[1] shl 4)+k[0]) xor (b[1]+sum) xor ((b[1] shr
 5)+k[1]));
     b[1]:=b[1]+ (((b[0] shl 4)+k[2]) xor (b[0]+sum) xor ((b[0] shr
 5)+k[3]));
     end;
 end;
 
 procedure DeTEARound(var b:TTEABlock; const k:TTEAKey);
 var sum,round:longword;
 begin
 sum:=TEAdelta shl 5;
 for round:=0 to 31 do
     begin
     b[1]:=b[1]- (((b[0] shl 4)+k[2]) xor (b[0]+sum) xor ((b[0] shr
 5)+k[3]));
     b[0]:=b[0]- (((b[1] shl 4)+k[0]) xor (b[1]+sum) xor ((b[1] shr
 5)+k[1]));
     sum:=sum-TEAdelta;
     end;
 end;
 -----------------------
 - eto shifrovanie odnogo bloka
 - mogu brosit modul shifrovaniya stroki
 -----------------------
 Posle etogo zashifrovannyj text codiruetsya transportnym kodekom :
 libo 1) kak objasneno vyshe - base64
 libo 2) kazhdyi byte kodirovat hex-kodom (2 simvola)
 
 Pered deshifrovaniem - obratnoe dekodirovanie
 
 OLS
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  * Origin: Golden Telecom (2:5020/400)
 
 

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Тема:    Автор:    Дата:    shifroval\'ni algoritm   Andrei Romazanov   20 Dec 2001 15:47:23   shifroval\'ni algoritm   Sergey Kabikov   20 Dec 2001 20:05:04   Re: shifroval\'ni algoritm   OLS   21 Dec 2001 10:27:50