Patent ID: 7707420

Claim:
A public-key encryption process for communicating messages between a sender device and a receiver device, comprising the steps of: for each message: a) encrypting a plaintext message into a ciphertext message, the encrypting step includes the step of producing an ephemeral key pair that is used to encrypt the plaintext message, wherein the ephemeral key pair is used for a single message between the sender and the receiver; b) generating a digital signature for the ciphertext message using the ephemeral key pair produced in the encrypting step, wherein the digital signature comprises a first value r and a second value s; and c) transmitting, from the sender, an encryption ephemeral public key X of the ephemeral key pair, the ciphertext message, and the second value s of the digital signature to the receiver; wherein the first value r of the digital signature is calculated at the receiver using a decrypted form of the plaintext message and the transmitted encryption ephemeral public key X, and the digital signature is validated based on the calculated first value r and the transmitted second value s.