• Provable Security of Authenticated Encryption Schemes 

      Engan, Sunniva (Bachelor thesis, 2022)
      Denne bacheloroppgaven ser på den bevisbare sikkerheten til randomized counter mode (RCM) og Galois counter mode (GCM). Dette gjøres ved å bruke sekvenser av spill for å strukturere bevisene. Vi vil bevise at randomized ...
    • Short Identity-Based Signatures with Tight Security from Lattices 

      Pan, Jiaxin; Wagner, Benedikt (Peer reviewed; Journal article, 2021)
      We construct a short and adaptively secure identity-based signature scheme tightly based on the well-known Short Integer Solution (SIS) assumption. Although identity-based signature schemes can be tightly constructed from ...
    • Shorter QA-NIZK and SPS with Tighter Security 

      Abe, Masayuki; Jutla, Charanjit; Ohkubo, Miyako; Pan, Jiaxin; Roy, Arnab; Wang, Yuyu (Chapter, 2019)
      Quasi-adaptive non-interactive zero-knowledge proof (QA-NIZK) systems and structure-preserving signature (SPS) schemes are two powerful tools for constructing practical pairing-based cryptographic schemes. Their efficiency ...
    • Signatures with Tight Multi-user Security from Search Assumptions 

      Pan, Jiaxin; Ringerud, Magnus (Peer reviewed; Journal article, 2020)
      We construct two tightly secure signature schemes based on the computational Diffie-Hellman (CDH) and factoring assumptions in the random oracle model. Our schemes are proven secure in the multi-user setting, and their ...
    • Signed (Group) Diffie–Hellman Key Exchange with Tight Security 

      Pan, Jiaxin; Qian, Chen; Ringerud, Magnus (Peer reviewed; Journal article, 2022)
      We propose the first tight security proof for the ordinary two-message signed Diffie–Hellman key exchange protocol in the random oracle model. Our proof is based on the strong computational Diffie–Hellman assumption and ...
    • Signed Diffie-Hellman Key Exchange with Tight Security 

      Pan, Jiaxin; Qian, Chen; Ringerud, Magnus (Peer reviewed; Journal article, 2021)
      We propose the first tight security proof for the ordinary two-message signed Diffie-Hellman key exchange protocol in the random oracle model. Our proof is based on the strong computational Diffie-Hellman assumption and ...
    • A Simple and Efficient Framework of Proof Systems for NP 

      Wang, Yuyu; Su, Chuanjie; Pan, Jiaxin; Chen, Yu (Peer reviewed; Journal article, 2023)
    • Tight Security for Authenticated Key Exchange Protocols and Signature Schemes 

      Ringerud, Magnus (Doctoral theses at NTNU;2023:244, Doctoral thesis, 2023)
    • Tighter Security for Generic Authenticated Key Exchange in the QROM 

      Pan, Jiaxin; Wagner, Benedikt; Zeng, Runzhi (Peer reviewed; Journal article, 2023)
      Home Advances in Cryptology – ASIACRYPT 2023 Conference paper Tighter Security for Generic Authenticated Key Exchange in the QROM Download book PDF Download book EPUB Tighter Security for Generic Authenticated Key ...
    • Tightly Secure Hierarchical Identity-Based Encryption 

      Langrehr, Roman; Pan, Jiaxin (Peer reviewed; Journal article, 2020)
      We construct the first tightly secure hierarchical identity-based encryption (HIBE) scheme based on standard assumptions, which solves an open problem from Blazy, Kiltz, and Pan (CRYPTO 2014). At the core of our constructions ...
    • Tightly-secure Key Encapsulation Mechanism and its Application 

      Zeng, Runzhi (Doctoral theses at NTNU;2024:367, Doctoral thesis, 2024)
      This thesis improves the security tightness of several cryptographic schemes and protocols in the post-quantum world, including key encapsulation mechanism, public-key encryption, and (password-based) authenticated key ...
    • Towards Oblivious Transfer in the Quantum Random Oracle Model 

      Sund, Espen (Master thesis, 2024)
      I 2022 presenterte Badrinarayanan, Masny og Mukherjee en effektiv uvitende-overføring i den tilfeldige orakelmodellen. Denne protokollen er basert på offentlig nøkkelkryptering med tett sikkerhet i flerbruker-tilfellet og ...
    • Unbounded HIBE with Tight Security 

      Langrehr, Roman; Pan, Jiaxin (Peer reviewed; Journal article, 2020)
      We propose the first tightly secure and unbounded hierarchical identity-based encryption (HIBE) scheme based on standard assumptions. Our main technical contribution is a novel proof strategy that allows us to tightly ...
    • Unconditionally Secure NIZK in the Fine-Grained Setting 

      Wang, Yuyu; Pan, Jiaxin (Peer reviewed; Journal article, 2022)
      Non-interactive zero-knowledge (NIZK) proof systems are often constructed based on cryptographic assumptions. In this paper, we propose the first unconditionally secure NIZK system in the AC0 -fine-grained setting. More ...