MATTR Grotto Networking This document defines an extension to the BBS Signature scheme that supports blind digital signatures, i.e., signatures over messages not known to the Signer. Discussion Venues This note is to be removed before publishing as an RFC. Discussion of this document takes place on the Crypto Forum Research Group mailing list (cfrg@ietf.org), which is archived at https://mailarchive.ietf.org/arch/browse/cfrg. Source for this draft and an issue tracker can be found at https://github.com/cfrg/draft-irtf-cfrg-bbs-blind-signatures.