Yeah. i've looked into that and still am. It looks very promising, but i don't really understand it up to a level where i'd be able to confidently explain it in a fashionable way yet.
Blinded bearer certificates (bb-certs) are a
very old and fairly simple technology, though for some reason it's never seen widespread use. It basically allows a "bank" to issue tokens which can be transferred 100% anonymously. These tokens could be something like "IOU 1 BTC", or they could indicate other things like "whoever holds this token is entitled to a bitcointalk.org copper membership". Unlike Monero or Wasabi, bb-cert transactions aren't merely mixing coins around to make the transaction graph (hopefully-)prohibitively difficult to follow: transaction histories simply can't exist at all. A bb-cert system would also be very scalable -- easily scaling to Visa-level volumes --, and with instant confirmation of transactions. The main downside is that it's fundamentally centralized, since each cert has to be
issued by some entity (though this entity could be a multisig arrangement).
I wrote a little article
here with several example use-cases. Note that since I wrote that:
- I learned that Cloudflare implemented an anti-captcha bb-cert thing in the form of
Privacy Pass, which is really cool, though it doesn't work perfectly yet and it seems that there isn't that much attention on this.
- Someone started working on
hookedin, which is a project for a complete bb-cert-based BTC payments system, though it's in the very early stages of development and isn't really usable yet.
I suggested bb-certs to ChipMixer in 2017, but they weren't at that time interested. (Not too surprising, since I wasn't offering to create it for them, an easy-to-deploy solution doesn't exist yet, and ideas are a dime a dozen.)