On the Security of RSA with Primes Sharing Least-Significant Bits

Abstract. We investigate the security of a variant of the RSA public-key cryptosystem called LSBS-RSA, in which the modulus primes share a large number of least-significant bits.We show that low public-exponent LSBS-RSA is inherently resistant to Partial Key Exposure (PKE) attacks in which least-significant bits of the secret exponent are revealed to the attacker, and in particular that the Boneh-Durfee-Frankel PKE attack [5] on low public-exponent RSA is less effective for LSBS-RSA systems than for standard RSA. On the other hand, we show that large public-exponent LSBS-RSA is more vulnerable to such attacks than standard RSA. An application to server-aided RSA signature generation is proposed.

• Type: Journal
• Year: 2004
• Where: AAECC
• Authors: Ron Steinfeld, Yuliang Zheng
• Keywords: AAECC 2004, Algorithms, Low Public-exponent Rsa, RSA Public-key Cryptosystem, Standard Rsa