Darius Mercadier

Sorbonne Université | UPMC · Laboratoire d'informatique de Paris 6 (LIP6)

The design of software countermeasures against active and passive adversaries is a challenging problem that has been addressed by many authors in recent years. The proposed solutions adopt a theoretical foundation (such as a leakage model) but often do not offer concrete reference implementations to validate the foundation. Contributing to the expe...

Bitslicing is a technique commonly used in cryptography to implement high-throughput parallel and constant-time symmetric primitives. However, writing, optimizing and protecting bitsliced implementations by hand are tedious tasks, requiring knowledge in cryptography, CPU microarchitectures and side-channel attacks. The resulting programs tend to be...

Cryptographic implementations deployed in real world devices often aim at (provable) security against the powerful class of side-channel attacks while keeping reasonable performances. Last year at Asiacrypt, a new formal verification tool named tightPROVE was put forward to exactly determine whether a masked implementation is secure in the well-dep...

We describe SKIVA, a customized 32-bit processor enabling the design of software countermeasures for a broad range of implementation attacks covering fault injection and side-channel analysis of timing-based and power-based leakage. We design the countermeasures as variants of bitslice programming. Our protection scheme is flexible and modular, all...

Cryptographic primitives are subject to diverging imperatives. Functional correctness and auditability pushes for the use of a high-level programming language. Performance and the threat of timing attacks push for using no more abstract than an assembler to exploit (or avoid!) the micro-architectural features of a given machine. We believe that a s...

Bitslicing is a programming technique commonly used in cryptography that consists in implementing a combinational circuit in software. It results in a massively parallel program immune to cache-timing attacks by design. However, writing a program in bitsliced form requires extreme minutia. This paper introduces Usuba, a synchronous dataflow languag...