This is constructive criticism. Thank you! I completely missed that I could hand the merchant string to a friend with a bank account and have them sign it. Pre

This is constructive criticism. Thank you! I completely missed that I could hand the merchant string to a friend with a bank account and have them sign it. Pretty obvious in retrospect! Its not perfect, but maybe reasonable enough to prevent resale by using a salted hash of the users ip. Wrt hash linking, theres chaums blind signature thing which looks solid. It feels like a cheap enough, private enough, and reliable enough solution is that can be rolled out in under 6 months is in this neighborhood; maybe this provides something to trigger someone who can do it to do it.