The Secret Key Capacity of a Class of Noisy Channels with Correlated Sources

Germán Bassi (1) , Pablo Piantanida (2, 3) , Shlomo Shamai (4)

1 KTH - KTH Royal Institute of Technology [Stockholm]
2 L2S - Laboratoire des signaux et systèmes
3 MILA - Montreal Institute for Learning Algorithms [Montréal]
4 Technion - Israel Institute of Technology [Haifa]

This paper investigates the problem of secret key generation over a wiretap channel when the terminals observe correlated sources. These sources are independent of the main channel and the users overhear them before the transmission takes place. A novel outer bound is proposed and, employing a previously reported inner bound, the secret key capacity is derived under certain less-noisy conditions on the channel or source components. This result improves upon the existing literature where the more stringent condition of degradedness is required. Furthermore, numerical evaluation of the achievable scheme and previously reported results for a binary model are presented; a comparison of the numerical bounds provides insights on the benefit of the chosen scheme.

Mots clés: information-theoretic security; secret key agreement; secret key capacity; wiretap channel; correlated sources

Domaines: Sciences de l'ingénieur [physics]

Germán Bassi, Pablo Piantanida, Shlomo Shamai. The Secret Key Capacity of a Class of Noisy Channels with Correlated Sources. Entropy, 2019, 21 (8), pp.732. ⟨10.3390/e21080732⟩. ⟨hal-02940461⟩