This proposal improves liveness guarantees for custodial ecash mints with on-chain reserves. It allows a mint operator to delegate control of mint reserves to third-party mint operators in a non-interactive way.
While the mint is in operation, it maintains unilateral control over the mint reserves. However, if the mint becomes unresponsive, the delegate mint can take over control of the funds and process withdrawals for the original mint's users.
A mint can delegate to multiple other mints. If a set of mints all act as delegates for eachother, they collectively inherit 1-of-n liveness properties. As long as one mint in the set is able to remain online, the users of all mints in the set are able to redeem their funds.
