cryptography and computer security 2002 - 01.ppt 2 [1]. Cryptography and computer security. ppt 3 [1]. Classical replace passwords. ppt 4 [1]. Classical transform password. 5 ppt [1]. Classical transform the product code and password. ppt 6 [1]. Modern cryptography. ppt 7 [1]. Modern a password-des.ppt 8 [1]. on the number theory. ppt 9 [1]. Public-key cryptography. pp t 10 [1]. Public-key encryption algorithm (continued). ppt 11 [1]. certification, Hash algorithm. ppt 13 [1]. Digital Signature Algorithm. ppt 17 [1].