That is a super cool idea. Earn badges x, y, and z (badges that are invented and authorized by separate independent parties) to earn the bitcoin.
I think we’d need the badge creators to sign the attribute keys but maybe we can add that to badge onboarding.
aren't they already signed at creation?
The authority needs to generate a key when the badges are assigned IIUC.
Maybe it's possible that it can be derived. I need to research more I think. It also might be simpler than pure ABE because badge holding is boolean vs a specific tier or type of a given badge.
https://github.com/fentec-project/gofe/blob/master/abe/ma-abe.go#L401
