  In this paper we proposed an authentication technique based on the user
cards, to improve the authentication process in systems that allows remote
access for the users, and raise the security rate during an exchange of their
messages. in this technique the server performs two functions, the first
function, register the users, and give him user ID, PIN code, and user private
card contains secrecy information, which is used to encrypt user messages by
using two kinds of encryption symmetric using RC4-Pr and asymmetric using RSA
encryption., the second function, distribute the user's public card if the user
demand that, in which the user sends the own authentication code with their own
user ID and recipient user ID to the authentication check, and then the server
sends the user public card to the recipient user, thus the sender user can send
the messages to recipient user without back to the server again. We attained
confidentiality using RC4-Pr and RSA encryption and message authentication,
user signature, and mutual secret key by using RSA encryption. in this paper we
also implement the proposal in [1] RC4-pr algorithm which is modified to
improve the key weakness of basic RC4.
