A complete study of P.K.I. (PKI’s Known Incidents) Nicolas Serrano Hilda Hadan L Jean Camp School of Informatics, School of Informatics, School of Informatics, Computing & Engineering Computing & Engineering Computing & Engineering Indiana University Indiana University Indiana University Bloomington Bloomington Bloomington
[email protected] [email protected] [email protected] Abstract— In this work, we report on a comprehensive used. However, there have been problems with PKI. There analysis of PKI resulting from Certificate Authorities’ (CAs) are reasons to reconsider this trust. For example, while the behavior using over 1300 instances. We found several cases mathematical foundations of the cryptography used in PKI where CAs designed business models that favored the issuance of digital certificates over the guidelines of the CA Forum, have been studied and demonstrated to be complex to crack, root management programs, and other PKI requirements. advances in hardware have turned computationally secure Examining PKI from the perspective of business practices, we algorithms into breakable ones. In addition, sometimes the identify a taxonomy of failures and identify systemic vulnera- implementation of these cryptographical algorithms intro- bilities in the governance and practices in PKI. Notorious cases duces flaws or vulnerabilities that are external to the core include the “backdating” of digital certificates, the issuance of these for MITM attempts, the lack of verification of a crypto-mathematical function, and that can be exploited by requester’s identity, and the unscrupulous issuance of rogue attackers. certificates. We performed a detailed study of 379 of these Sometimes, the vulnerabilities are not in the cryptographic 1300 incidents. Using this sample, we developed a taxonomy protocols, implementing code or hardware, but in the busi- of the different types of incidents and their causes.