In this paper, we propose an efficient RSA public key encryption scheme, which is an improved version of original RSA scheme. The proposed RSA encryption scheme is based on linear group over the ring of integer mod a composite modulus n which is the product of two distinct prime numbers. In the proposed scheme the original message and the encrypted message are h x h square matrices with entities in z(n) indicated via l(h,z(n)). Since the original RSA Scheme is a block cipher in which the original message and cipher message are integer in the interval [0,n-1] for solve integer modulus n. Therefore, in this paper, we generalize RSA encryption scheme in order to be implemented in the general linear group on the ring of integer mod n. Furthermo...