Intel Corporation
SIDE CHANNEL PROTECTION FOR XMSS SIGNATURE FUNCTION

Abstract:

In one example an apparatus comprises one or more processors, and signature logic to receive a first plurality of state variables for use in a secure hash signature operation, compute a second plurality of operations from the first plurality of state variables to generate a corresponding second plurality of outputs, receive a signature key to be used in a secure hash operation, divide the signature key into a third plurality of chunks, implement, in a pseudo-random order, a fourth plurality of add operations to add the second plurality of outputs to the third plurality of chunks to update the first plurality of state variables. Other examples may be described.