Cryptographic algorithms can be attacked by the exploitation of their leakage or by observing the effect of transient perturbations. The most cost-effective protections consist in letting the algorithm leak and get faulted, but in such a subtle way the attacker cannot derive any exploitable secret from these sneaky side-channel pieces of information. Secure-IC has developed special technologies for the cryptographic blocks to be resilient both against passive and active attacks. They include redundant encodings, multi-valued logics, lightweight key hashing and message blinding.
Attacks that exploit the leakage of a circuit are extremely difficult to protect against, since any tiny bias in a countermeasure can ultimately be detected with enough measurements. Secure-IC has therefore developed a patented technology that immunizes the circuits even if billion of traces can be garnered on the device. The concept is fairly simple: the leakage is merely encrypted with an implementation-dependent key. Therefore, all training phases are made impossible, since every device has a unique leakage. Furthermore, the attack of a given device will reveal the cryptographic key encrypted by the implementation key; the security is as high as that of cryptographic block since the encryption uses a one-time pad of the same length as the cryptographic key.