In this paper we put forward the notion of Built-in Tamper Resilience (BiTR) for cryptographic protocols, capturing the idea that the protocol that is encapsulated in a hardware token preserves its security properties even when an adversary may tamper with its secret state. Our definition is within the UC model, and can be viewed as unifying and extending several prior related works. We provide a composition theorem for BiTR security of protocols, as well as several BiTR constructions for specific cryptographic protocols or tampering function classes. In particular, relaxing the tamper-proof token assumption of Katz's work, we achieve UC-secure computation based on a hardware token that may be susceptible to affine tampering attacks. We also present BiTR proofs for identification and signature schemes in the same tampering model. We next observe that non-malleable codes can be used as state encodings to prove the BiTR property and show new positive results for deterministic non-malleable encodings (as opposed to probabilistic that were previously known) for various classes of tampering functions.
Category / Keywords: cryptographic protocols / tamper-proof hardware, tamper resilience, universal composability, secure computation, non-malleable codes Publication Info: Asiacrypt 2011 Date: received 1 Oct 2010, last revised 16 Jan 2012 Contact author: sgchoi at cs umd edu Available formats: PDF | BibTeX Citation Version: 20120116:194912 (All versions of this report) Discussion forum: Show discussion | Start new discussion