中文摘要：

分析了阈下信道产生的原因及其在数字签名中的应用,对Schnorr签名中存在的宽带和窄带阈下信道进行了具体分析。设计了一个新的阈下信道封闭协议,新协议要求看守参与会话密钥的生成,确保会话密钥的随机性和隐私性。证明了新协议在保证签名者签名权力的前提下,完全封闭了Schnorr签名中由随机会话密钥所引入的阈下信道。新协议的安全性基于求解离散对数问题的困难性和哈希函数的安全性,在复杂度方面,签名者和看守各执行1次模指数运算。

英文摘要：

The reasons for the appearance of subliminal channels and their applications in digital signature schemes are analyzed.The wideband and narrowband subliminal channels in the Schnorr signature are discussed.And a new subliminal-free protocol is designed.In the new protocol,the warden participates in the generation of session keys in order to guarantee their randomness and privacy.It is shown that the protocol can completely close the subliminal channels existing in the random session keys in the Schnorr signature scheme.In addition,the signature authority of the signer is guaranteed.The security of the proposed protocol is based on both the discrete logarithm intractability assumption and the existence of collision-free hash functions.To generate a signature,it only needs to perform one modular exponentiation for each of the signer and the warden.