Last modified on Feb 10, 2017

Goals

  • The RSE needs to perform several computational steps to check whether a received Basic Safety Message (BSM) has been sent by a revoked EE
  • This document lists the corresponding requirements

Assumptions

The RSE received a CRL as defined in Use Case 6: CRL Download.

Process Steps

  1. Optional: RSE expands the CRL and calculates the linkage values for the current i-period based on the CRL entries (linkage seeds) of the CRL pseudonym certificate section. This only applies if the RSE wants to verify received BSMs. 
  2. Whenever RSE receives a new unknown OBE identification certificate, RSE will calculate the certificate digest of that unknown certificate and check whether the CRL lists it
    1. If yes, then RSE discards the received certificate
    2. Otherwise, RSE accepts the received certificate as verified
  3. Optional: Whenever RSE receives a new unknown certificate, it checks whether the linkage value of that unknown certificate is listed in RSE's expanded CRL (from Step 1)
    1. If yes, then RSE discards the received certificate
    2. Otherwise, RSE accepts the received certificate as verified
  4. Optional: Before the end of each i-period, RSE will: 
    1. Update its expanded CRL and calculate the linkage value for the next i-period
    2. Remove entries from the expanded CRL that belong to revoked devices that ran out of certificates, if a CRL entry indicated that the revoked device does not have any more valid certificates. Note that the RSE may not immediately remove such entries, but add a safety buffer. 

Not Doing

  • For POC and CV Pilots, RSE application certificates are not listed on CRLs but revocation is enforced by not renewing certificates. At a later stage, this might be changed. 
  • In that case, the following requirement needs to be added: If RSE recognizes itself on the CRL, the RSE will stop sending over-the-air DSRC messages related to the indicated PSID/SSP. This also applies if RSE recognizes that the ECA, that issued RSE's enrollment certificate, or the PCA that issued RSE's certificates, has been revoked.