The security of the messages being exchanged between two hosts on a network is of primary concern today for the internet community. An authentication server establishes trusted communication between two hosts. Then the two hosts exchange RSA (Rivest-Shamir-Adleman) encrypted messages. These messages are decrypted with the help of decryption keys provided by the authentication server to the receiver. These keys are passed to the receiver during the exercise to establish authenticated communication between the two hosts.