Patent Document ID: 20080301459
Application ID: 12040212
Patent Flag: 0

Claim One:
1. A method of encrypting a message in a manner that counters power analysis attacks, wherein a long-term private cryptographic key has been selected and a long-term public cryptographic key has been determined based on said long-term private cryptographic key and a base point on a given elliptic curve, said base point having a prime order, said method comprising: determining a modular inverse of said long-term private cryptographic key; generating a sessional private cryptographic key and a sessional public cryptographic key; determining an implicit signature based on said modular inverse of said long-term private cryptographic key, said sessional private cryptographic key, said sessional public cryptographic key and said long-term private cryptographic key; determining a shared secret cryptographic key based on said implicit signature; and encrypting a message using said shared secret cryptographic key.