Cryptology ePrint Archive: Report 2016/1028

Ratcheted Encryption and Key Exchange: The Security of Messaging

Mihir Bellare and Asha Camper Singh and Joseph Jaeger and Maya Nyayapati and Igors Stepanovs

Abstract: We give a theoretical treatment of ratcheting, lifting it from a technique used in secure messaging protocols to a cryptographic primitive. To allow a modular treatment, we decouple the creation of keys from their use. We define ratcheted key exchange and give a protocol proven to achieve it. We then define ratcheted encryption and show how to achieve it generically from ratcheted key exchange and standard encryption.

Category / Keywords: cryptographic protocols / Symmetric encryption, forward security, backward security, authenticated key exchange, Diffie-Hellman

Date: received 30 Oct 2016

Contact author: istepano at eng ucsd edu

Available format(s): PDF | BibTeX Citation

Version: 20161101:020757 (All versions of this report)

Short URL:

Discussion forum: Show discussion | Start new discussion

[ Cryptology ePrint archive ]