武汉大学密码学课件-张焕国教授

111111121222HASHHASH642135,642135,214365214365kk123456123456351642351642P=P=BEEAKFYDJXUQYHYJIQRYHTYJIQFBQDUYJIIKFBEEAKFYDJXUQYHYJIQRYHTYJIQFBQDUYJIIKFUHCQDUHCQDINFORMATIONSECURITYINFORMATIONSECURITYppiij(i,j=1,2,3,…,n)j(i,j=1,2,3,…,n)p(i)=jp(i)=jp(j)=ip(j)=iVigenreVigenre••••••••DESDESDESDESDESDESDESDES3333DESDES••••••••CC((x)=03xx)=03x33+01x+01x22+01x+02+01x+02DD((x)=0Bxx)=0Bx33+0Dx+0Dx22+09x+0E+09x+0EAESAESByteSub(25)ByteSub(25)AESAESSSECBECBCBCCBCCFBCFBOFBOFBXCBCXCBCCTRCTRg(x)=xg(x)=x44xx33g(x)g(x)nnnnGFGF22nn222222nn22••••••••