A Comment on “Cryptographic Applications of Brahmagupta–Bhãskara Equation”
Amr Youssef · IEEE Transactions on Circuits and Systems I Fundamental Theory and Applications · 2007
Murthy and Swamy proposed a symmetric key encryption system based on Brahmagupta-Bhaskara equation over GF(p). In this comment, we show that breaking this system is equivalent to solving a set of linear equations over the field of rational numbers. Our attack, typically, requires as low as three known plaintext-ciphertext pairs and allows the cryptanalyst to fully recover the secret key