Key Recovery and Message Attacks on NTRU-Composite

NTRU is a fast public key cryptosystem presented in 1996 by Hoffstein, Pipher and Silverman of Brown University. It operates in the ring of polynomials Z[X]/(XN − 1), where the domain parameter N largely determines the security of the system. Although N is typically chosen to be prime, Silverman proposes taking N to be a power of two to enable the use of Fast Fourier Transforms. We break this scheme for the specified parameters by reducing lattices of manageably small dimension to recover partial information about the private key. We then use this partial information to recover partial information about the message or to recover the private key in its entirety.

• Type: Conference
• Year: 2001
• Where: EUROCRYPT
• Authors: Craig Gentry
• Keywords: Cryptology, EUROCRYPT 2001, Partial Information, Private Key, Public Key Cryptosystem