On Small Secret Key Attack against RSA with High Bits Known Prime Factor.
Yasufumi Hashimoto · IACR Cryptology ePrint Archive · 2010
It is well known that if the higher half bits of a prime factor are known or the secret key is small enough then the RSA cryptosystem is broken (e.g. [Coppersmith, J. Cryptology, 1997] and [Boneh-Durfee, Eurocrypt’99]). Recently, Sarkar-MaitraSarkar [Cryptology ePrint Archiv, 2008/315] proposed attacks against RSA under the conditions that the higher bits of a prime factor is known and the secret key is small. In the present paper, we improve their attacks to be effective for larger secret keys.