Trust in Secure Sockets Layer–based communications is traditionally provided by Certificate (or Certification) Authorities (CAs) in the form of signed certificates. Checking the validity of a certificate involves three steps: (i) checking its expiration date, (ii) verifying its signature, and (iii) ensuring that it is not revoked. Currently, such certificate revocation checks (i.e., step (iii) above) are done either via Certificate Revocation Lists (CRLs), or Online Certificate Status Protocol (OCSP) servers. Unfortunately, despite the existence of these revocation checks, sophisticated cyber-attackers can still trick web browsers to trust a revoked certificate, believing that it is still valid. Although frequently updated , nonced , and timestamped certificates can reduce the frequency and impact of such cyber-attacks, they add a huge burden to the CAs and OCSP servers. Indeed, CAs and/or OCSP servers need to timestamp and sign on a regular basis all the responses, for every certificate they have issued, resulting in a very high overhead. To mitigate this and provide a solution to the described cyber-attacks, we present CCSP : a new approach to provide timely information regarding the status of certificates, which capitalizes on a newly introduced notion called Signed Collections . In this article, we present in detail the notion of Signed Collections and the complete design, implementation, and evaluation of our approach. Performance evaluation shows that CCSP (i) reduces space requirements by more than an order of magnitude, (ii) lowers the number of signatures required by six orders of magnitude compared to OCSP-based methods, and (iii) adds only a few milliseconds of overhead in the overall user latency.

中文翻译：

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压缩证书状态协议的设计与实现

对基于安全套接字层的通信的信任传统上由证书（或认证）机构 (CA) 以签名证书的形式提供。检查证书的有效性涉及三个步骤：（i）检查其到期日期，（ii）验证其签名，以及（iii）确保它不会被撤销。目前，此类证书撤销检查（即上述步骤 (iii)）是通过证书撤销列表 (CRL) 或在线证书状态协议 (OCSP) 服务器完成的。不幸的是，尽管存在这些撤销检查，老练的网络攻击者仍然可以欺骗网络浏览器信任撤销证书，相信它仍然有效。虽然经常更新,随机的， 和时间戳证书可以降低此类网络攻击的频率和影响，但它们给 CA 和 OCSP 服务器增加了巨大的负担。事实上，CA 和/或 OCSP 服务器需要时间戳和标志定期所有响应，对于他们颁发的每个证书，都会导致非常高的开销。为了减轻这种情况并为所描述的网络攻击提供解决方案，我们提出了 CCSP：一种提供有关证书状态的及时信息的新方法，它利用了一个新引入的概念，称为签名收藏. 在本文中，我们详细介绍了签名收藏以及我们方法的完整设计、实施和评估。性能评估表明，CCSP (i) 将空间需求减少了一个数量级以上，(ii) 与基于 OCSP 的方法相比，将所需的签名数量降低了六个数量级，并且 (iii) 仅增加了几毫秒的总用户延迟的开销。