Patent ID: 6931126

Claim:
A method comprising the steps of: encrypting a data message m at a transmitter processor using a primary transmitter secret key z, wherein z is known to the transmitter processor but not to a receiver processor, to form a quantity E; preparing a quadruplet (a new , b new ,s new , E) at the transmitter processor where: a new =z*y c modulo p; b new =g c modulo p; s new =signature c ( a new ,b new ,E ); where y=g x modulo p, c is a random number, x is a receiver secret key of the receiver processor, and the parameters g, x, and p are picked using a known encryption method; wherein s new is a signature which is determined by using the same random number c that was used to determine a new and b new ; transmitting the quadruplet (a new , b new ,s new , E) from the transmitter processor to the receiver processor; verifying the signature s new at the receiver processor; decrypting a new and b new at the receiver processor by using the receiver secret key x to get the primary transmitter secret key z; using the primary transmitter secret key z to decrypt the quantity E and thereby obtaining the message m at the receiver processor.