Due to the enormous demand for networking services, the performance and security of information has to be improved. To provide information security, numerous cryptographic algorithms were proposed by various researchers, out of which RSA algorithm is one the most popular algorithm. RSA algorithm uses linear congruence method which restricted the operation to specific class of values. RSA algorithm needs exponential time for decryption of message. By extending the RSA algorithm using congruence class and selecting the key in random, the security of algorithm can be increased. Higher the congruence class index, higher will be its level of security. For each of the congruence class element, complexity of algorithm will be same but there will be increase in the level of security. The basic idea behind this implementation is that by converting the given linear congruence into congruence class and solving them algebraically, actual information can be produced. This paper contains the comparison between linear congruence and congruence class using RSA algorithm. Finally we contend that, due to congruence class implementation, the complexity of algorithm will remain same as that of regular RSA algorithm with enhancement in information security by random congruence class key selection.Copy Right, IJAR, 2016,. All rights reserved.