[tor-access] Specification for bypassing CAPTCHAs using blinded tokens

Hi everyone,

I've been interning at Cloudflare for the past 3 months and have been working on developing an implementation of the blinded tokens spec that George and Filippo developed a while back.

We've updated aspects of the original spec, the newest spec can now be viewed here: https://github.com/cloudflare/challenge-bypass-specification. We're happy to hear comments from any of you on the design and on the capacity of the solution for preserving anonymity.

We've managed to build a test copy of the protocol along with an extension that carries out the required operations. The extension is not completely finished yet, but we're looking towards making that open source as well when it is done.

Thanks, Alex