Cryptography beyond the black-box model

• Applicant: Professor Dr. Sebastian Faust
• Subject Area: Theoretical Computer Science
• Term: from 2015 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 277831812

• Final Report Year: 2022

Final Report Abstract

The main goals of this project were to overcome the limitations of the black-box model in realworld scenarios and to design a sound theory for analyzing cryptographic implementations. The work done in this project significantly enhanced the state-of-the-art and contributed to the development of provably secure cryptographic implementations. In particular, we investigated side-channel attacks, fault-attacks, and hardware trojans. In all three areas, we developed sound security models and provided efficient countermeasures. In the following we briefly summarize our contribution. ● Side-channel resilience: We developed two practical-oriented verification tools to verify leakage resilience of algorithms and circuits: scVerif analyzes hardware-specific leakages and STRAPS analyzes the natural nature of noisy leakage. Additionally, we developed secure compilers to protect arbitrary cryptographic primitives against side-channel leakage. ● Tamper resilience: Faulty keys are a common problem that leads to various security vulnerabilities. We analyzed this security challenge and followed two research directions. First, we developed a non-malleable code that cannot be attacked by an adversary with bounded space. Finally, we constructed an authenticated encryption scheme that is resistant against functions from a given set of tamper functions. ● Trojan resilience: Similar to the approach of tamper resilience, we designed a secure compiler to protect arbitrary circuits against such attacks and we successfully worked on trojan resilient encryption schemes.

Publications

• Circuit Compilers with O(1/\log (n)) Leakage Rate. EUROCRYPT 2016
  M. Andrychowicz, S. Dziembowski, S. Faust
  
• Private Circuits III: Hardware Trojan-Resilience via Testing Amplification. CCS 2016
  S. Dziembowski, S. Faust, F.-X. Standaert
  
• Amortizing Randomness Complexity in Private Circuits. ASIACRYPT 2017
  S. Faust, C. Paglialonga, T. Schneider
  
• Non-Malleable Codes for Space-Bounded Tampering. CRYPTO 2017
  S. Faust, K. Hostáková, P. Mukherjee, D. Venturi
  
• Composable Masking Schemes in the Presence of Physical Defaults & the Robust Probing Model. CHES 2018
  S. Faust, V. Grosso, S. M. Del Pozo, C. Paglialonga, F.-X. Standaert
  
• General State Channel Networks. CCS 2018
  S. Dziembowski, S. Faust, K. Hostáková
  
• Simple Refreshing in the Noisy Leakage Model. ASIACRYPT 2019
  S. Dziembowski, S. Faust, K. Zebrowski
  
• Unifying Leakage Models: From Probing Attacks to Noisy Leakage. J. Cryptol 2019
  A. Duc, S. Dziembowski, S. Faust
  
• Deterministic Wallets in a Quantum World. CCS 2020
  N. A. Alkadri, P. Das, A. Erwig, S. Faust, J. Krämer, S. Riahi, P. Struck
  
• Fuzzy Asymmetric Password-Authenticated Key Exchange. ASIACRYPT 2020
  A. Erwig, J. Hesse, M. Orlt, S. Riahi
  
• Masking in Fine-Grained Leakage Models: Construction, Implementation and Verification. CHES 2021
  G. Barthe, M. Gourjon, B. Grégoire, M. Orlt, C. Paglialonga, L. Porth
  
• Towards Tight Random Probing Security. CRYPTO 2021
  G. Cassiers, S. Faust, M. Orlt, F.-X. Standaert