Patent ID: 8752126

Claim:
A method for enhancing security of a broadcast or multicast system, wherein, after defining by a base station system parameters of the broadcast/multicast system, the method comprises: receiving by the base station a registration request message from a mobile terminal, the registration request message contains device identity information of the mobile terminal; and registering by the base station the mobile terminal according to the registration request message and transmitting by the base station an authorized key to the mobile terminal upon successful registration, wherein, the method further comprises: receiving by the mobile terminal a broadcast/multicast encryption text transmitted from the base station, wherein, the mobile terminal decrypts the broadcast/multicast encryption text with the authorized key, wherein, an operation of defining by a base station system parameters of the broadcast/multicast system comprises: defining two q-order cyclic groups of (G 1 , +) and (G 2 , ·), wherein, q is a prime number, G 1 is irreversible in Diffie-Hellman calculation, and P is a generator of G 1 ; defining e representing bilinear transformation on G 1 and G 2 ; and defining h(·) representing a unidirectional hash function, wherein, an operation of registering by the base station the mobile terminal according to the registration request message comprises: verifying, by the base station, physical information of the mobile terminal, and when the mobile terminal complies with the registration request message, selecting by the base station randomly a number n−1 of different elements from Z* q , wherein, n is an integer larger than or equal to 2, and selecting from G 1 and publishing two elements Q 1 and Q 2 ; constructing randomly an (n−1)-order secret polynomial f(x)εZ p [x]; calculating Q K from Q K =f(0)PεG 1 and V i from V i =f(v i )P(i=0, 1, . . . , n−2) according to a constructed polynomial, wherein, i ranges from 0 to n−2; and extracting the device identity information ID x from the registration request message, and calculating V x from V x =f(IDx)(Q 1 +Q 2 ) according to the device identity information ID x .