'Enabling Blockchain Innovations with Pegged Sidechains' by Adam Back, Matt Corallo, Luke Dashjr, Mark Friedenbach, Gregory Maxwell, Andrew Miller, Andrew Poelstra, Jorge Timón & Pieter Wuille.
https://blockstream.com/sidechains.pdf nostr:note10cnqsqx3p94twwj8uq5q54m380y08303gv0xy95pev9s6yehwh3qju8y9c