Ravva Santosh1, Challa Narasimham2, and Pallam shetty3

1Department of Information Technology, MVGR College of Engineering, India

2Department of Computer Science and Engineering, SR Engineering College, India

3Department of Computer Science and Systems Engineering, Andhra University, India

Abstract: LSBS-RSA is a variation of RSA cryptosystem with modulus primes p, q, sharing a large number of least significant bits. As original RSA, LSBS-RSA is also vulnerable to the short secret exponent attack. Sun et al. [15] studied this problem and

 they provided the bound for secret exponent. Their bound does not reduce to the optimal bound 0.292 for original RSA, which is provided by Boneh-Durfee. In this paper, we achieve the bound which reduces to the Boneh-Durfee optimal bound.