Active and Passive Side-Channel Key Recovery Attacks on Ascon

Physical exposure of devices to adversaries in unprotected environments in the era of the Internet of Things (IoT) necessitates evaluation of cryptographic hardware implementations against side-channel analysis (SCA). The Ascon authenticated cipher has been accepted to Round 2 of the U.S. National Institute of Standards and Technology (NIST) Lightweight Cryptography (LWC) Standardization Process, and was selected as the first choice of the CAESAR committee for the lightweight use case. In this paper, we evaluate the vulnerability of Ascon to both passive and active SCA attacks. Using a lightweight implementation of Ascon on an Artix-7 FPGA, we demonstrate a successful statistical ineffective fault analysis (SIFA) attack using voltage glitches on the supply pin of the FPGA chip. Using only 280 correct values of the output authentication tags under fault injection into a pair of S-boxes, one subset of the secret key (equivalent to two bits) is recovered. We also demonstrate that a power analysis attack using a deep learning technique is able to find the secret key using 24K power traces during S-box computations at the beginning of the Initialization stage of Ascon. Conversely, classical DPA and CPA attacks fail to find the correct key with more