Biblio

Development in the area of quantum technologies led to the appearance of first quantum computers. The threat of using a quantum computer for cryptanalysis requires wide implementing post-quantum security in computing algorithms and communication protocols. We evaluate the computational power of some existing quantum computers to illustrate the relevance of research in post-quantum security. One of the best ways to test post-quantum protocols is to embed them into some non-critical but widely-used sphere. Secure messaging is an excellent example of such an application. In the paper, we analyze the post-quantum security of well-known messaging specification Signal, which is considered to have high-security properties. The core of Signal specification is the Double Ratchet protocol. We notice and explain why it is not a post-quantum secure scheme. After that, we suggest some possible ways to improve the security features of Signal specification.

Post-quantum secure communication has attracted much interest in recent years. Known computationally secure post-quantum key agreement protocols are resource intensive for small devices. These devices may need to securely send frequent short messages, for example to report the measurement of a sensor. Secure communication using physical assumptions provides information-theoretic security (and so quantum-safe) with small computational over-head. Security and efficiency analysis of these systems however is asymptotic. In this poster we consider two secure message communication systems, and derive and compare their security and efficiency for finite length messages. Our results show that these systems indeed provide an attractive alternative for post-quantum security.