An Attack Against the Revised Murthy–Swamy Cryptosystem

Murthy and Swamy proposed a symmetric key encryption system based on Brahmagupta-Bhaskara equation over . In response to a known plaintext attack presented by the author, Murthy and Swamy modified their system to resist this attack. In this correspondence, we show that the modified cryptosystem can still be broken by a low complexity known plaintext attack.