Registration Authority

IEEE offers Registration Authority programs or registries which maintain lists of unique identifiers under standards and issue unique identifiers to those wishing to register them. The IEEE Registration Authority assigns unambiguous names to objects in a way which makes the assignment available to interested parties.

ACPCTREEID (ACPCTID): IEEE Std 1609.2.1™

IEEE Std 1609.2.1 specifies a mechanism for certificate management known as Activation Codes for Pseudonym Certificates (ACPC). Within this system, entities known as Certificate Access Managers (CAMs) create structures known as binary trees. The binary trees are used to derive access codes for the end entities managed by the CAM such that each access code is unique to a particular end entity and is used to decrypt that end entity’s certificates for a particular time period. The end-entity determines which access code to use based on a unique identifier within the tree, assigned by the CAM. The tree is assigned an identifier, known as the AcpcTreeId, which is globally unique within the entire system of devices that use IEEE Std 1609.2.1. The unique assignment of AcpcTreeId values is managed by the IEEE Registration Authority (IEEE RA). This form allows applications to request between 1 and 16 AcpcTreeId values.

For more details, see IEEE Std 1609.2.1 or the tutorial


Registration Fees

Product Fees
IEEE Std 1609.2.1 AcpcTreeId US $700
IEEE does not accept requests for applicant-specified identifiers.

Application Information

Please search our public AcpcTreeId listing to determine whether your company or any parent/subsidiary companies already own an AcpcTreeId assignment. If your Organization has already been issued an assignment, please email us to obtain contact information for the Administrator of the assignment.

  1. Complete and submit the AcpcTreeId application (PDF) by fax or mail. Applications expire after 30 days.
  2. Any questions regarding your application will be sent to the REQUESTOR.
  3. Applications are reviewed within 90 days and additional clarification may be required by our review committee.
  4. Once the application has been approved, it will be processed within 7 business days. Assignment details are sent to the primary applicant upon approval or rejection.

Related Standards

This assignment applies to the IEEE 1609.2.1-2020 - IEEE Standard for Wireless Access in Vehicular Environments (WAVE) - Certificate Management Interfaces for End-Entities

The application and AcpcTreeId assignees have an obligation and responsibility to manage the assigned ACPCTREEID and to minimize unused AcpcTreeIds.