Patent ID: 7570759

Claim:
An encryption and signature generation method executing on a device, the method includes encrypting a received message having at least one message segment, and comprises: a) receiving an initial hash value and a message block, the message block comprising a key; b) generating a current hash value based upon a hash function that receives as input the initial hash value and the message block; c) encrypting a received message segment into a cipher segment using at least a part of the current hash value; d) generating a next hash value using the current hash value and the received message segment as an input to the hash function; e) sequentially repeating steps c-d for a subsequently received message segment of the received message, wherein the next hash value becomes the current hash value to be used to encrypt the subsequently received message segment; and f) generating a message signature that includes the next hash value generated by step d using a finally received message segment of the received message.