Randomized trial examines related-key attacks' impact on stream ciphers in multi-client scenarios, suggesting vulnerabilities.
Key Points
This research investigates the security of HE-friendly stream ciphers against related-key attacks. It aims to understand the effectiveness of round requirements in multi-client environments.
Proposed two practical related-key attacks based on linearization methods and one using SAT solving.
Analyzed the security of Rasta, Masta, and Pasta stream ciphers with a focus on their differential characteristics.
Experimentally verified and discussed the validity conditions of the trivial linearization attack.
Successfully broke both instances of Pasta (2/2), most instances of Masta (9/16), and Rasta (5/9).
Demonstrated vulnerabilities in current cipher specifications related to multi-client scenarios.
Provided theoretical discussions and empirical verifications of linearization attack conditions.