Paper 2018/185

A privacy-preserving method for temporarily linking/revoking pseudonym certificates in vehicular networks

Marcos A. Simplicio Jr., Eduardo Lopes Cominetti, Harsh Kupwade Patil, Jefferson E. Ricardini, Leonardo T. D. Ferraz, and Marcos Vinicius M. Silva


Vehicular communication (V2X) technologies are expected to become increasingly common in the future. Although they enable improvements on transportation safety and efficiency, the large scale deployment of V2X requires addressing some challenges. In particular, to prevent abuse by drivers and by the system itself, V2X architectures must: (1) ensure the authenticity of messages, which is usually accomplished by means of digital certification; and (2) preserve the privacy of honest users, so owners of non-revoked certificates cannot be easily identified and tracked by eavesdroppers. A promising design to address these requirements is the Security Credential Management System (SCMS), which is currently among the main candidates for protecting V2X communications in the United States. Even though SCMS provides efficient, scalable and privacy-preserving mechanisms for managing V2X-oriented certificates, in this article we show that its certificate revocation process can be further enhanced. Namely, we present two birthday attacks against SCMS's revocation process, both of which degrade the system's security as time passes and more certificates are revoked. We then describe an alternative design to prevent such security degradation with minimal computational overhead. In complement to these security gains, we also describe a mechanism for improving the flexibility of the revocation procedure, allowing certificates (as well as their owner's privacy) to be temporarily revoked in an efficient manner. This should be useful, for example, to implement suspension mechanisms or to aid in investigations by law-enforcement authorities.

Note: The manuscript has been submitted to IEEE Trustcom 2018 (

Available format(s)
Cryptographic protocols
Publication info
Published elsewhere. MINOR revision.2018 17th IEEE International Conference On Trust, Security And Privacy In Computing And Communications/ 12th IEEE International Conference On Big Data Science And Engineering (TrustCom/BigDataSE)
Vehicular communicationssecuritypseudonym certificatesrevocable privacylinkability
Contact author(s)
mjunior @ larc usp br
2020-04-21: revised
2018-02-20: received
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Creative Commons Attribution


      author = {Marcos A.  Simplicio Jr. and Eduardo Lopes Cominetti and Harsh Kupwade Patil and Jefferson E.  Ricardini and Leonardo T.  D.  Ferraz and Marcos Vinicius M.  Silva},
      title = {A privacy-preserving method for temporarily linking/revoking pseudonym certificates in vehicular networks},
      howpublished = {Cryptology ePrint Archive, Paper 2018/185},
      year = {2018},
      doi = {10.1109/TrustCom/BigDataSE.2018.00182},
      note = {\url{}},
      url = {}
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