Trust Revoked — Practical Evaluation of OCSP- and CRL-Checking Implementations

  • Manuel KoschuchEmail author
  • Ronald Wagner
Conference paper
Part of the Communications in Computer and Information Science book series (CCIS, volume 554)


When deploying asymmetric cryptography robust ways to reliably link a public key to a certain identity have to be devised. The current standard for doing so are X.509v3 certificates. They are used in HTTPS and SSH as well as in code-, e-mail-, or PDF-signing. This widespread use necessitates the need for an efficient way of revoking such certificates in case of a compromised private key. Two methods are currently available to deal with this problem: the older Certificate Revocation Lists (CRL), and the newer Online Certificate Status Protocol (OCSP). In this work we perform a practical evaluation of how different software like web-browsers or PDF viewers deal with OCSP, in particular when the OCSP server cannot be reached. We find widely varying behavior, from silently accepting any certificates to completely blocking access. In addition we search an existing data-set of X.509v3 HTTPS certificates for revocation information, finding that almost 85 % of them contain neither CRL nor OCSP information, thereby rendering any practical revocation attempt nearly useless.


OCSP CRL X.509v3 Browser Evaluation 



Manuel Koschuch is being supported by the MA23 - Wirtschaft, Arbeit und Statistik - in the course of the funding programme “Stiftungsprofessuren und Kompetenzteams für die Wiener Fachhochschul-Ausbildungen”.


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Copyright information

© Springer International Publishing Switzerland 2015

Authors and Affiliations

  1. 1.Competence Centre for IT-Security, FH Campus WienUniversity of Applied SciencesViennaAustria

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