Patent ID: 8625784

Claim:
A broadcast encryption method comprising: generating at least one Strong Diffie-Hellman tuple in accordance with the equation (1/(x+1))G, (1/(x+2))G, . . . , and (1/(x+n))G, where G denotes a generator of a group having an order p on an elliptic curve, x denotes an arbitrary element selected from a group Zp of order p, and n denotes a total number of users; generating a message encryption key using a public key and a secret key generated using the Strong Diffie-Hellman tuple; encrypting a message using the message encryption key; generating a message header using a sum of a plurality of Strong Diffie-Hellman tuples corresponding to an authorized user group; and transmitting the message header, the encrypted message, and the Strong Diffie-Hellman tuple to at least one receiver.