Faultless Key Recovery: Iteration-Skip and Loop-Abort Fault Attacks on LESS accepted by CHES 2026

Our paper Faultless Key Recovery: Iteration-Skip and Loop-Abort Fault Attacks on LESS has been accepted by CHES 2026.

We show that a simple fault on the binary array used to build LESS’s GGM tree is enough for full key recovery. Depending on the parameter set and fault model, one or two faulty signatures often suffice, and even the least favorable case stays within a couple hundred signatures.