??????????????????????????????????DES????,????DES????????????????????????,????DES????,?????????;??????????,??DES????????,???????????????????

1
??? ???????????

• ??????????????????????????????????DES??
  ??,????DES????????????????????????,????DES????,???
  ????????????????,??DES????????,??????????????????
  ?

2
??????????????

• 1.Triple DES
• 2.IDEA
• 3.RC5
• ??????????,??????,?Blowfish,CAST,??RC2?

3
1 TRIPLE DES

• DES????????????????DES????????????????Quisquater??
  ??????768 bits????????????DES?????,?
• K.W.Campbell and M.J.Wiener
• Proof that DES is not a group
• In Advances in Cryptology