as defined in [@wu2016acorn]. An 8-bit side-channel protected version of AES-GCM and a 1-bit side-channel protected version of ACORN are implemented as described in [@diehl2018face]. Both implementations comply with lightweight version of the CAESAR HW API [@homsirikamol2015gmu].

Our methodology for side-channel resistant is threshold implementation (TI), which has wide acceptance as a provably secure Differential Power Analysis (DPA) countermeasure [@nikova2006threshold]. In TI, sensitive data is separated into shares and the computations are performed on these shares independently. TI must satisfy three properties: (1) Non-completeness: Each share must lack at least one piece of sensitive data, (2) Correctness: The final recombination of the result must be correct, and (3) Uniformity: An output distribution should match the input distribution. To ensure uniformity, we refresh TI shares after non-linear transformations using randomness. We use a hybrid 2-share/3-share approach, where all linear transformations in each cipher are protected using two shares, which are expanded to three shares only for non-linear transformations.

To verify the resistance against DPA, we employ the Test Vector Leakage Assessment methodology in [@gilbert2011testing]. We leverage a “fixed versus random” non-specific t-test, in which we randomly interleave first fixed test vectors and then randomly-generated test vectors, leading to two sequences with 