Cryptology ePrint Archive: Report 2018/1097

End-to-End Secure Mobile Group Messaging with Conversation Integrity and Deniability

Michael Schliep and Nicholas Hopper

Abstract: In this paper, we describe Mobile CoWPI, a deployable, end-to-end secure mobile group messaging application with proofs of security. Mobile CoWPI allows dynamic groups of users to participate in, join, and leave private, authenticated conversations without requiring the participants to be simultaneously online or maintain reliable network connectivity. We identify the limitations of mobile messaging and how they affect conversational integrity and deniability. We define strong models of these security properties, prove that Mobile CoWPI satisfies these properties, and argue that no protocol that satisfies these properties can be more scalable than Mobile CoWPI. We also describe an implementation of Mobile CoWPI and show through experiments that it is suitable for use in real-world messaging conditions.

Category / Keywords: cryptographic protocols / secure messaging, mobile messaging

Date: received 12 Nov 2018

Contact author: schli116 at umn edu

Available format(s): PDF | BibTeX Citation

Version: 20181115:160522 (All versions of this report)

Short URL: ia.cr/2018/1097


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