International Association
for Cryptologic Research

The increasing use of resource limited devices with less memory, less computing resource and less power supply, motivates the adoption of lightweight cryptography to provide security solution. ASCON is a finalist and GIMLI is a round 2 candidate of NIST lightweight cryptography competition. ASCON is a sponge function based authenticated encryption (AE) scheme suitable for high performance applications. It is suitable for use in environments like Internet of Things (IoT) where large number of very constrained devices communicate with high-end servers. The drawback is that fault analyses like Statistical Ineffective fault attack (SIFA) and Sub-Set Fault Analysis (SSFA) are possible. GIMLI is also a sponge function based AE scheme which is susceptible to SIFA. In this work, we modify ASCON 128a and GIMLI exploiting the pseudo-random properties of Cellular Automata (CA) to prevent these attacks. We analyse and show that these attacks are inapplicable in the reinforced cipher.