Verifiable Random Functions (VRFs)
draft-irtf-cfrg-vrf-15

(Via drafts-eval@iana.org): IESG/Authors/ISE:

The IANA Functions Operator has reviewed draft-irtf-cfrg-vrf-15 and has the following comments:

We understand that this document (which does not include an IANA Considerations section) doesn't require any registry actions.

If this assessment is not accurate, please respond as soon as possible.

Thank you,

Amanda Baber
IANA Operations Manager

[Ballot comment]
I've reviewed this document (admittedly skimming over the sections on the specific algorithms), and it's a useful and readable guide to VRFs. It is ready for publication as an RFC.

One side note for the RG/editors: the state of implementation may be useful to publish as a snapshot at the time of publication. If the guidance in section 6 to remove the section before publication stands, does the RG maintain pointers to implementation elsewhere (e.g., in a wiki)?

The draft is currently missing the required statements described in RFC 5743 Section 2.1. The boilerplate at the top of page 1 also lists the intended status as standards track, which is not permitted for IRTF drafts. These will need a revised draft to address.

Technical Summary

This document describes several Verifiable Randon Function (VRF) functions, which can be used as a public-key version of a keyed cryptographic hash. The document describes algorithms for VRFs based on Elliptic Curves and RSA. It includes detailed documentation on implementing these algorithms through a framework of cipher suites. The document also provides an overview of the construction's security properties and information about which properties are needed in different scenarios. This document is a product of the Crypto Forum Research Group (CFRG) in the IRTF.

Working Group Summary

The document was adopted back in 2017. It has gone through multiple iterations and improvements after adoption. This includes broadening the scope from Elliptic Curve VRFs to a wider spectrum of VRFs by including an RSA full-domain hash version. This document predated the CFRG hash-to-curve document but has subsequently been adapted to be compatible with the constructions provided in that document. There was a Research Group Last Call for the draft in February 2021.

Document Quality

This document went through an expert review by Chloe Martindale on the Crypto Review panel and extensive review from CFRG participants, including Christopher Peikert, Burt Kaliski, Christopher Wood, Riad Wahby, Antonio Marcedone, Christopher Patton, Hoeteck Wee, and others. There is a reference C++ implementation with test vectors, and there are alternative implementations of different aspects of this draft available in Sage, Python, C, JavaScript, and Rust.

Personnel

Nick Sullivan is the Document Shepherd.
Colin Perkins is the IRTF Chair.