With the explosion of networks and huge amount of data transmitted along, securing data content is becoming more and more important. The protection afforded to an automated information system is to attain the applicable objectives of preserving the integrity, accountability, authenticity and non repudiation. Many cryptographic Symmetric and Asymmetric algorithms are proposed. But symmetric key have some weakness such as suffering Brute Force, desynchronization etc.To get rid of from the weakness and reduce the system workload, we adopt Rivest Shamir Adleman (RSA) to construct an asymmetric key [2].Among the asymmetric algorithms the most widely accepted and implemented approach is the RSA encryption. Pseudo Random Numbers (PRN) are used in a number of areas such as Cryptography, Scientific Statistical Simulation etc. In cryptography the pseudo random number is a crucial element in the secret keys for cryptography algorithms and protocols. In this paper we have introduced new concept of RSA algorithm which is based on PN (Prime Numbers). These PN are selected from PRN sequence. The PN are used as input to RSA (Rivest Shamir Adleman) algorithm [3]. This technique is implemented by MATLAB