Automated Symbolic Verification of Telegram’s MTProto 2.0

Marino Miculan, Nicola Vitacolonna

2021

Abstract

MTProto 2.0 is a suite of cryptographic protocols for instant messaging at the core of the popular Telegram messenger application. In this paper we analyse MTProto 2.0 using the symbolic verifier ProVerif. We provide fully automated proofs of the soundness of MTProto 2.0’s authentication, normal chat, end-to-end encrypted chat, and rekeying mechanisms with respect to several security properties, including authentication, integrity, secrecy and perfect forward secrecy; at the same time, we discover that the rekeying protocol is vulnerable to an unknown key-share (UKS) attack. We proceed in an incremental way: each protocol is examined in isolation, relying only on the guarantees provided by the previous ones and the robustness of the basic cryptographic primitives. Our research proves the formal correctness of MTProto 2.0 w.r.t. most relevant security properties, and it can serve as a reference for implementation and analysis of clients and servers.

Paper Citation

in Harvard Style

Miculan M. and Vitacolonna N. (2021). Automated Symbolic Verification of Telegram’s MTProto 2.0. In Proceedings of the 18th International Conference on Security and Cryptography - Volume 1: SECRYPT, ISBN 978-989-758-524-1, pages 185-197. DOI: 10.5220/0010549601850197

in Bibtex Style

@conference{secrypt21,
author={Marino Miculan and Nicola Vitacolonna},
title={Automated Symbolic Verification of Telegram’s MTProto 2.0},
booktitle={Proceedings of the 18th International Conference on Security and Cryptography - Volume 1: SECRYPT,},
year={2021},
pages={185-197},
publisher={SciTePress},
organization={INSTICC},
doi={10.5220/0010549601850197},
isbn={978-989-758-524-1},
}

in EndNote Style

TY - CONF

JO - Proceedings of the 18th International Conference on Security and Cryptography - Volume 1: SECRYPT,
TI - Automated Symbolic Verification of Telegram’s MTProto 2.0
SN - 978-989-758-524-1
AU - Miculan M.
AU - Vitacolonna N.
PY - 2021
SP - 185
EP - 197
DO - 10.5220/0010549601850197