Smooth Projective Hashing and Password-Based Authenticated Key Exchange from Lattices

Abstract. We describe a public-key encryption scheme based on lattices — specifically, based on the hardness of the learning with error (LWE) problem — that is secure against chosen-ciphertext attacks while admitting (a variant of) smooth projective hashing. This encryption scheme suffices to construct a protocol for password-based authenticated key exchange (PAKE) that can be proven secure based on the LWE assumption in the standard model. We thus obtain the first PAKE protocol whose security relies on a lattice-based assumption. 1 Password-Based Authenticated Key Exchange Protocols for password-based authenticated key exchange (PAKE) enable two users to generate a common, cryptographically-strong key based on an initial, low-entropy, shared secret (i.e., a password). The difficulty in this setting is to prevent off-line dictionary attacks where an adversary exhaustively enumerates potential passwords on its own, attempting to match the correct password to observed protocol exe...

• Type: Conference
• Year: 2009
• Where: ASIACRYPT
• Authors: Jonathan Katz, Vinod Vaikuntanathan
• Keywords: ASIACRYPT 2009, Authenticated Key Exchange, Cryptology, Encryption Scheme, Pake Protocol