Intel Corporation
COUNTERMEASURES FOR SIDE-CHANNEL ATTACKS ON PROTECTED SIGN AND KEY EXCHANGE OPERATIONS

Abstract:

Embodiments are directed to countermeasures for side-channel attacks on protected sign and key exchange operations. An embodiment of storage mediums includes instructions for commencing a process including an elliptic curve scalar multiplication (ESM) operation including application of a secret scalar value; splitting the secret scalar value into two random scalar values; counting a number of leading `0` bits in the scalar value and skipping the number of leading `0` bits in processing; performing an ESM iteration for each bit of the secret scalar value beginning with a most significant `1` bit of the scalar value including a Point Addition operation and a Point Double operation for each bit on randomized points; performing ESM operation dummy iterations equal to the number of leading `0` bits; and returning an output result for the ESM operation.