Enabling 3-share threshold implementations for all 4-bit s-boxes

Abstract

Threshold Implementation (TI) is an elegant and promising lightweight countermeasure for hardware implementations to resist first order Differential Power Analysis (DPA) in the presence of glitches. Unfortunately, in its most efficient version with only three shares, it can only be applied to 50% of all 4-bit S-boxes so far. In this paper, we introduce a new approach, called factorization, that enables us to protect all 4-bit S-boxes with a 3-share TI. This allows—for the first time—to protect numerous important ciphers to which the 3-share TI countermeasure was previously not applicable, such as CLEFIA, DES, DESL, GOST, HUMMINGBIRD1, HUMMINGBIRD2, LUCIFER, mCrypton, SERPENT, TWINE, TWOFISH among others. We verify the security and correctness with experiments on simulations and real world power traces and finally provide exemplary decompositions of all those S-boxes.