Based on DL(discrete logarithm)problem, S1 is decrypted by introducing a multi-channel service parameter and a special polynomial function, S2 is decrypted by Chinese Remainder Theorem.

• 基于离散对数困难问题，引入多频道服务参数和特殊多项式函数来解密S1，利用中国剩余定理来解密S2。