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.