This is however not true for the prominent case of encryption. Indeed, all existing soundness results assume that the adversary only uses honestly generated keys. While this assumption is acceptable in the case of asymmetric encryption, it is clearly unrealistic for symmetric encryption. In this paper, we provide with several examples of attacks that do not show-up in the classical Dolev-Yao model, and that do not break the IND-CPA nor INT-CTXT properties of the encryption scheme.
Our main contribution is to show the first soundness result for symmetric encryption and arbitrary adversaries. We consider arbitrary indistinguishability properties and an unbounded number of sessions.
This result relies on an extension of the symbolic model, while keeping standard security assumptions: IND-CPA and IND-CTXT for the encryption scheme.Category / Keywords: cryptographic protocols / security protocols, dishonest keys, symmetric encryption Publication Info: To appear in the proceedings of the conference on Principles of Security and Trust (POST12) Date: received 6 Jan 2012 Contact author: scerri at lsv ens-cachan fr Available formats: PDF | BibTeX Citation Note: Full version Version: 20120107:155740 (All versions of this report) Discussion forum: Show discussion | Start new discussion