Provable Security of Real-World Protocols

Brij Bhooshan Gupta, Aakanksha Tewari

Internet of Things (IoT) devices have restricted resources and energy; however, they require regular updates and identification from other devices and the backend server. Thus, security is also a major concern, and the most common way to do it is mutual authentication between the communicating parties. Provable security aims to provide concrete mathematical proof for ensuring the protocol’s security. Modern cryptographic protocols deploy “game-based” security models, which have an adversary that can carry out potential attacks over the concerned system. The adversary in the universally composable security model interacts with both real-world and ideal-world environments. The adversary can eavesdrop into all the communications and can schedule the activation sequence of the entities. The real spreading of IoT services requires customized security and privacy levels to be guaranteed. K. Ouafi et al. have extended Vaudeney’s model to incorporate the notion of strong privacy.

Muthuramakrishnan Venkitasubramaniam

Véronique Cortier, Bogdan Warinschi, Eugen Zălinescu

Travis Denny

Leveraging quantum mechanics, cryptographers have devised provably secure key sharing protocols. Despite proving the security in theory, real-world application falls short of the ideal. Last year, cryptanalysts completed an experiment demonstrating a successful eavesdropping attack on commercial quantum key distribution (QKD) systems. This attack exploits a weakness in the typical real-world implementation of quantum cryptosystems. Cryptanalysts have successfully attacked several protocols. In this paper, we examine the Kak quantum cryptography protocol and how it may perform under such attacks.

P.M.T.B Sandirigama

Cas J. F. Cremers, Mang Zhao

Recent years have seen many advances in designing secure messaging protocols, aiming at provably strong security properties in theory or high efficiency for real-world practical deployment. However, important trade-off areas of the design space inbetween these elements have not yet been explored.In this work we design the first provably secure protocol that at the same time achieves (i) strong resilience against fine-grained compromise, (ii) temporal privacy, and (iii) immediate decryption with constant-size overhead, notably, in the post-quantum (PQ) setting. Besides these main design goals, we introduce a novel definition of offline deniability suitable for our setting, and prove that our protocol meets it, notably when combined with a PQ offline deniable initial key exchange.