Biblio

Security of transient fault secured IP cores against piracy, false claim of ownership can be achieved during high level synthesis, especially when handling DSP or multimedia cores. Though watermarking that involves implanting a vendor defined signature onto the design can be useful, however research has shown its limitations such as less designer control, high overhead due to extreme dependency on signature size, combination and encoding rule. This paper proposes an alternative paradigm called `hardware steganography' where hidden additional designer's constraints are implanted in a fault secured IP core using entropy thresholding. In proposed hardware steganography, concealed information in the form of additional edges having a specific entropy value is embedded in the colored interval graph (CIG). This is a signature free approach and ensures high designer control (more robustness and stronger proof of authorship) as well as lower overhead than watermarking schemes used for DSP based IP cores.

It is notably challenging to design an efficient and secure signature scheme based on error-correcting codes. An approach to build such signature schemes is to derive it from an identification protocol through the Fiat-Shamir transform. All such protocols based on codes must be run several rounds, since each run of the protocol allows a cheating probability of either 2/3 or 1/2. The resulting signature size is proportional to the number of rounds, thus making the 1/2 cheating probability version more attractive. We present a signature scheme based on double circulant codes in the rank metric, derived from an identification protocol with cheating probability of 2/3. We reduced this probability to almost 1/2 to obtain the smallest signature among code-based signature schemes based on the Fiat-Shamir paradigm, around 22 KBytes for 128 bit security level. Furthermore, among all code-based signature schemes, our proposal has the lowest value of signature plus public key size, and the smallest secret and public key sizes. We provide a security proof in the Random Oracle Model, implementation performances, and a comparison with the parameters of similar signature schemes.