US Patent 10419408 In-place authentication scheme for securing intra-vehicle communication

In some implementations, a scheme for data communication in an automobile includes generating a cleartext message to be transmitted to a second ECU, generating a pseudo-random counter by applying a pseudorandom function to a counter value that is incremented for each cleartext message generated by the ECU; combining the cleartext message and the pseudo-random counter to create a randomized message; selecting from a plurality of available cryptography techniques, a selected cryptography technique; applying to the randomized message, the selected cryptography technique to create a ciphertext; and transmitting to the second ECU over the CAN bus, the ciphertext.