Provable Security for PKI Schemes

Sara Wrótniak; Hemi Leibowitz; Ewa Syta; Amir Herzberg

Paper 2019/807

Provable Security for PKI Schemes

Sara Wrótniak

Hemi Leibowitz

, The College of Management Academic Studies, Rishon Lezion, Israel

Ewa Syta

, Trinity College, Hartford, CT

Amir Herzberg

, University of Connecticut, Storrs, CT

Abstract

PKI schemes provide a critical foundation for applied cryptographic protocols. However, there are no rigorous security specifications for realistic PKI schemes, and therefore, no PKI schemes were proven secure. Cryptographic systems that use PKI are analyzed by adopting overly simplified models of the PKI, often, simply assuming securely-distributed public keys. This is problematic given the extensive reliance on PKI, the multiple failures of PKI systems, and the complexity of both proposed and deployed systems, which involve complex requirements and models. We present game-based security specifications for PKI schemes, and analyze important and widely deployed PKIs: PKIX and two variants of Certificate Transparency (CT). All PKIs are based on the X.509v3 standard and its CRL revocation mechanism. Our analysis identified few subtle vulnerabilities, and provides reduction-based proofs showing that the PKIs ensure specific requirements under specific models (assumptions). To our knowledge, this is the first reduction-based proof of security for a realistic PKI scheme, e.g., supporting certificate chains.

Metadata

Available format(s): PDF
Category: Public-key cryptography
Publication info: Published elsewhere. To appear in ACM SIGSAC CCS 2024
Keywords: public-key infrastrcture provable-security
Contact author(s): sara wrotniak @ uconn edu
leibo hemi @ gmail com
ewa syta @ trincoll edu
amir herzberg @ gmail com
History: 2024-05-14: last of 8 revisions; 2019-07-14: received; See all versions
Short URL: https://ia.cr/2019/807
License: CC BY

BibTeX

@misc{cryptoeprint:2019/807,
      author = {Sara Wrótniak and Hemi Leibowitz and Ewa Syta and Amir Herzberg},
      title = {Provable Security for {PKI} Schemes},
      howpublished = {Cryptology {ePrint} Archive, Paper 2019/807},
      year = {2019},
      url = {https://eprint.iacr.org/2019/807}
}