Probabilistic Cycle Detection for Schneier's Solitaire Keystream Algorithm

Wiem Tounsi (1, 2) , Benjamin Justus (3) , Nora Cuppens-Bouhlahia (2, 1) , Frédéric Cuppens (2, 1) , Joaquin Garcia Alfaro (4, 5, 6)

1 LUSSI - Département Logique des Usages, Sciences sociales et Sciences de l'Information
2 Lab-STICC_TB_CID_SFIIS
3 Lab-STICC - Laboratoire des sciences et techniques de l'information, de la communication et de la connaissance
4 TSP - Télécom SudParis
5 SAMOVAR - Services répartis, Architectures, MOdélisation, Validation, Administration des Réseaux
6 CNRS - Centre National de la Recherche Scientifique

Pencil-and-paper ciphers are plausible solutions that could provide lightweight protection to the communication of resource-constrained devices. A good example in this category is Schneier's Solitaire cipher. In this paper, we propose a probabilistic solution that is able to estimate Solitaire's keystream cycle length. We also present a variation of Solitaire's original design, and evaluate the resulting construction in terms of predictability. We conduct statistical randomness tests on both the original design and the modified version based on the NIST randomness test suite. The results show that our approach improves the randomness of original Solitaire's output sequences.

Mots clés: Randomness Evaluation; Cycle Detection; Pseudo-Random Number Generators (PRNG); Pencil-and-Paper Ciphers; Cryptography; ICT Security

Domaines: Ordinateur et société [cs.CY]

Wiem Tounsi, Benjamin Justus, Nora Cuppens-Bouhlahia, Frédéric Cuppens, Joaquin Garcia Alfaro. Probabilistic Cycle Detection for Schneier's Solitaire Keystream Algorithm. SERE-C 2014 : IEEE 8th International Conference on Software Security and Reliability, Jun 2014, San Francisco, United States. pp.113 - 120, ⟨10.1109/SERE-C.2014.29⟩. ⟨hal-01073179⟩