关键词: 广播加密, 秘密共享, 抗合谋性, 离散对数, 付费电视

Abstract: The broadcast encryption scheme was required to minimize the amount of decryption computation by many applications. Concerning this requirement, a new broadcast encryption scheme was proposed by using secret sharing in another way. The improved scheme reduced the amount of decryption computation by pre-reconstructing the interpolation share. Analysis shows that the improved scheme just needs to encrypt once the plaintext, and then the subscribers can decrypt the cipher text using their secret keys with less computation. The improved scheme can also remove and add subscribers securely without the changing of subscribers' secret keys, and is of collusion-resistant property.

Key words: broadcast encryption, secret sharing, collusion-resistance, discrete logarithm, pay-TV