Patent ID: 7646872

Claim:
A method carried out by a first system for establishing a secure bidirectional communication path between the first system and a second system for an exchange of one or more messages, the method comprising: generating a first key pair having a first public key and a first private key; generating a second key pair having a second public key and a second private key, the second public key being generated based upon a shared secret known to the first system and the second system; sending the second public key and the first public key to the second system; receiving a third public key and a fourth public key generated by the second system, the fourth public key being generated based upon the shared secret; calculating a first master key based upon the first private key, the second private key, the third public key and the fourth public key, wherein the first master key is configured to be used in encryption of one or more messages; generating a new second key pair having a new second public key and a new second private key; receiving a new fourth public key from the second system, and calculating a new master key based upon the first private key, the new second private key, the third public key, and the new fourth public key using an elliptic curve calculation.