Abstract: Disclosed herein is a method of provisioning a message authentication protocol in a system of connected devices, the method comprising, by at least one of the connected devices: generating a private key and a public key; transmitting the public key to each other connected device; generating, by a sequence of hash operations using the private key, a hash tree, wherein each leaf node of the hash tree can have two or more values, each of the two or more values being associated with a respective nonce value, and wherein each leaf node has a hash computed from the concatenation of the respective nonce values; signing a root of the hash tree with the private key; and transmitting the root and the root signature to each other connected device.