Svetla Nikova
Research Expert (Onderzoekskader)
KU Leuven, Belgium
Title:
Threshold Cryptography against combined attacks
Abstract:
Recent attacks show that there is a need for protecting implementations jointly against side-channel and fault attacks. Analogously, modern MPC protocols consider active security, i.e. against malicious parties which do not only passively eavesdrop but also actively deviate from the protocol. This provides an opportunity for the field of threshold implementations to evolve with MPC and achieve provable secure implementations against combined passive and active physical attacks.
In this talk we will first introduce Threshold Implementations applied to protect various ciphers against SCA. After that we will discuss two recent proposals for combined countermeasures: CAPA and M&M, which both start from passively secure threshold schemes and extend those with information-theoretic MAC tags for protection against active adversaries. While similar in their most basic structure, the two proposals explore very different adversary models and thus employ completely different implementation techniques. CAPA considers the field-probe-and-fault model, which is the embedded analogue of multiple parties jointly computing a function with at least one of the parties honest. Accordingly, CAPA is strongly based on the actively secure MPC protocol SPDZ and inherits its provable security properties in this model. Since this results in very expensive implementations, M&M works in a similar but more realistic adversary model and uses existing building blocks from previous passively secure implementations to build more efficient actively secure threshold cryptography.
Biography:
Dr. Svetla Nikova is currently a Research Expert in Cryptography and Computer Security in the research group COSIC at ESAT, KU Leuven, Belgium. Prior to that she was assistant professor in University of Twente, NL. Her main research topics include: Side-channel resistant implementations, Secret sharing schemes and Multi-Party Computation, Boolean functions and symmetric cryptographic primitives. She is a co-author of more than 100 research papers in international journals and conferences. Dr. Nikova has been managing and contributed to a large number of research projects (EU, Belgian and US). Most recently she has been a co-PI of a research project about Threshold Implementations funded by NIST, US. She is a co-supervisor of 10 PhD students and has served as an examiner in PhD committees. Svetla Nikova is an elected member of the Board of Directors of the Trust in Digital Life. She is a member of the steering committee of CARDIS and WAIFI, she has been serving in a number of PCs and a member of the Board of Directors of IACR.