In this paper, we investigate the secure coding issue for a wiretap channel model with fixed main channel and varying wiretap channel, by assuming that legitimate parties can obtain the wiretapping channel state information (CSI) after some time delay. For the symmetric degraded delay CSI case, we present an explicit weak security scheme by constructing secure polar codes on a one-time pad chaining structure, and prove its weak security, reliability and capability of approaching the secrecy capacity of perfect CSI case with delay CSI assumption. Further for the symmetric no-degraded delay CSI case, we present a modified multi-block chaining structure in which the original subset of frozen bit is designed for conveying functional random bits securely. Then we combine this modified multi-block chaining structure with the weak security scheme to construct an explicit strong security polar coding scheme, and prove its strong security, reliability and also the capability of approaching the secrecy capacity of perfect CSI case with delay CSI assumption. At last, we carry out stimulations to prove the performance of both secure schemes.

中文翻译：

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具有延迟窃听信息的安全 Polar 编码

在本文中，我们通过假设合法方可以在一段时间延迟后获得窃听信道状态信息（CSI），研究具有固定主信道和不同窃听信道的窃听信道模型的安全编码问题。对于对称降级延迟CSI案例，我们通过在一次性填充链结构上构造安全极性码，提出了一种显式弱安全方案，并证明了其弱安全性、可靠性和接近具有延迟CSI的完美CSI案例的保密能力的能力假设。此外，对于对称无降级延迟 CSI 情况，我们提出了一种改进的多块链接结构，其中冻结位的原始子集设计用于安全地传送功能随机位。然后我们将这种修改后的多块链结构与弱安全方案相结合，构造了一个显式强安全极性编码方案，并证明了其强大的安全性、可靠性以及在延迟CSI假设下接近完美CSI案例保密能力的能力。最后，我们进行了刺激以证明两种安全方案的性能。