A method for device authentication comprises receiving, by processing hardware of a first device, a message from a second device to authenticate the first device. The processing hardware retrieves a secret value from secure storage hardware operatively coupled to the processing hardware. The processing hardware derives a validator from the secret value using a path through a key tree, wherein the path is based on the message, wherein deriving the validator using the path through the key tree comprises computing a plurality of successive intermediate keys starting with a value based on the secret value and leading to the validator, wherein each successive intermediate key is derived based on at least a portion of the message and a prior key. The first device then sends the validator to the second device.