Single Event Transient Fault Analysis of ELEPHANT cipher

Abstract: In this paper, we propose a novel fault attack termed as Single Event Transient Fault Analysis (SETFA) attack, which is well suited for hardware implementations. The proposed approach pinpoints hotspots in the cypher's Sbox combinational logic circuit that significantly reduce the key entropy when subjected to faults. ELEPHANT is a parallel authenticated encryption and associated data (AEAD) scheme targeted to hardware implementations, a finalist in the Lightweight cryptography (LWC) competition launched by NIST. In this work, we investigate vulnerabilities of ELEPHANT against fault analysis. We observe that the use of 128-bit random nonce makes it resistant against many cryptanalysis techniques like differential, linear, etc., and their variants. However, the relaxed nature of Statistical Fault Analysis (SFA) methods makes them widely applicable in restrictive environments. We propose a SETFA-based key recovery attack on Elephant. We performed Single experiments with random plaintexts and keys, on Dumbo, a Sponge-based instance of the Elephant-AEAD scheme. Our proposed approach could recover the secret key in 85-250 ciphertexts. In essence, this work investigates new vulnerabilities towards fault analysis that may require to be addressed to ensure secure computations and communications in IoT scenarios.