• 0-RTT Key Exchange with Full Forward Secrecy 

      Günther, Felix; Hale, Britta; Jager, Tibor; Lauer, Sebastian (Chapter, 2017)
      Reducing latency overhead while maintaining critical security guarantees like forward secrecy has become a major design goal for key exchange (KE) protocols, both in academia and industry. Of particular interest in this ...
    • Authenticated Key Exchange and Signatures with Tight Security in the Standard Model 

      Han, Shuai; Jager, Tibor; Kiltz, Eike; Liu, Shengli; Pan, Jiaxin; Riepel, Doreen; Schäge, Sven (Peer reviewed; Journal article, 2021)
      We construct the first authenticated key exchange protocols that achieve tight security in the standard model. Previous works either relied on techniques that seem to inherently require a random oracle, or achieved only ...
    • Highly Efficient Key Exchange Protocols with Optimal Tightness 

      Cohn-Gordon, Katriel; Cremers, Cas; Gjøsteen, Kristian; Jacobsen, Håkon; Jager, Tibor (Journal article; Peer reviewed, 2019)
      In this paper we give nearly tight reductions for modern implicitly authenticated Diffie-Hellman protocols in the style of the Signal and Noise protocols, which are extremely simple and efficient. Unlike previous approaches, ...
    • On Optimal Tightness for Key Exchange with Full Forward Secrecy via Key Confirmation 

      Gellert, Kai; Gjøsteen, Kristian; Jacobsen, Håkon; Jager, Tibor (Journal article; Peer reviewed, 2023)
      A standard paradigm for building key exchange protocols with full forward secrecy (and explicit authentication) is to add key confirmation messages to an underlying protocol having only weak forward secrecy (and implicit ...
    • Practical and tightly-secure digital signatures and authenticated key exchange 

      Gjøsteen, Kristian; Jager, Tibor (Journal article; Peer reviewed, 2018)
      Tight security is increasingly gaining importance in real-world cryptography, as it allows to choose cryptographic parameters in a way that is supported by a security proof, without the need to sacrifice efficiency by ...
    • Symmetric Key Exchange with Full Forward Security and Robust Synchronization 

      Boyd, Colin Alexander; Davies, Gareth T.; de Kock, Bor; Gellert, Kai; Jager, Tibor; Millerjord, Lise (Peer reviewed; Journal article, 2021)
      We construct lightweight authenticated key exchange protocols based on pre-shared keys, which achieve full forward security and rely only on simple and efficient symmetric-key primitives. All of our protocols have rigorous ...