Embedding formally proved code in a smart card: converting B to C

Smart cards are small embedded devices with strong security requirements. To fulfil those requirements, formal methods appear as promising techniques. The B method has already been used to model smart-card components. However, smart cards have also very strong programming constraints, both for memory usage and computing power. Currently, the code generated from a B specification does not meet those constraints. This paper presents some classical optimisation techniques that are well-suited for B specifications and that need to be included within a code generator to embed this generated code.