Techniques related to a technique comprising dividing an update into a number of portions, generating, for the first portion, a first portion hash value, generating, for the second portion, a second portion hash value, generating a first branch hash value comprising a hash of a concatenation of the first portion hash value and the second portion hash value, generating a root hash value by concatenating the first branch hash value and a second branch hash value, generating a signature based on the root hash value and a private key, generating an update header comprising the signature, the root hash value, and a hash tree comprising first and second portion hash values, the first branch hash value, and the root hash value, transmitting the update header to a client device for authentication, and transmitting one or more of the number of portions to the client device.