Komunikasi Antar Komputer Secara Rahasia Lewat Kanal Publik

Internet gives some facilities to pick up some information from all places around the world through public channels. Unfortunately, information which is sent to the intended recipient through a public channel is also transparent for other users of internet. An alternative solution is using cryptography , namely RSA public key cryptography, to conceal the information against an unauthorized person. This paper investigates factors which have influence on the success of RSA public key cryptography based eoinmunication between different types of computers. The results show that delay time between characters of a ciphertext and a primality test are required. The delay time is found to depend on data rates and types of computers. In order to generate public and secret keys three common methods to do a primality test are used, namely Miller-Rabin, Lehman and Fermat. Miller-Rabin method needs the shortest time to find large prime numbers among the three method