一类基于(t,n)门限密码的匿名潜信道方案

Anonymous Subliminal Channel Scheme Based on (t,n) Threshold Cryptosystem

分析了现有潜信道方案秘密信息泄漏、签名伪造、匿名身份不可追踪等安全漏洞以及潜信息滥用、协议过程复杂、签名认证运算开销大等不足之处。将门限密码与潜信道相结合,提出了一类基于(t,n)门限密码的匿名潜信道方案,实现了潜消息的门限可验证性与发送者的不可区分性,有效地保护了签名者的隐私信息,必要时又可对匿名身份实施追踪,避免了潜消息恢复权力与发送者匿名性滥用的缺陷,防止了对签名进行联合攻击和广义伪造攻击的安全隐患。方案中协议与算法安全、简洁、高效,降低了软硬件实现的系统开销,可广泛应用于计算机与无线通信等网络环境。

Security threats and system weakness of present subliminal channel schemes are analyzed. Combining Shamir Lagrange interpolation formula based secret-sharing scheme and subliminal channel, a threshold subliminal channel scheme with conditional anonymity based on （t, n） threshold cryptosystem is presented. The threshold secret-sharing of the scheme enables the subliminal message to be recoverable only by no less than t members of the n receivers, and the secret piece of each member can remain valid and secure after subliminal message recovering, so the scheme achieves multi-secret sharing. The probabilistic encryption algorithm and identity blinding make the subliminal message sender indistinguishable with other ordinary signers for secrecy protection, and the anonymity can also be conveniently revoked if necessary. The scheme prevents coalition attack and generalized signature forgery, avoids the misuse of subliminal message producing and recovering. Further detailed analyses also justify its brevity, security, high efficiency, and thus considerable improvement on system overheads regarding software and hardware application.