From jlrubin at mit.edu Mon Nov 29 23:32:12 2021 From: jlrubin at mit.edu (Jeremy) Date: Mon, 29 Nov 2021 15:32:12 -0800 Subject: [Lightning-dev] Half-Delegation & Chaperones for Decker Channels Message-ID: Just a minor curiosity I figured was worth mentioning on the composition of delegations and anyprevout... DA: Let full delegation be a script S such that I can sign script R and then R may sign for a transaction T. DB: Let partial delegation be a script S such that I can sign a tuple (script R, transaction T) and R may sign T. A simple version of this could be done for scriptless multisigs where S signs T and then onion encrypts to the signers of R and distributes the shares. However, under such a model, if T is signed by S with AnyPrevOut, then T is now arbitrarily rebindable. Therefore let us define more strictly: DC: Let half-delegation be a script S such that I can sign a tuple (script R, transaction T) and R may sign T and revealing T/R does grant authorization to any other party. The signer of R could choose to sign with APO, in which case they make the txn rebindable. They could also reveal the private keys for R similarly. For "correct" use, R should sign with SIGHASH_ALL, binding the transaction to a single instance. Observation: a tuple script R + transaction T can, in many cases, be represented by script R || CTV. Corollary: half-delegation can be derived from full delegation and a covenant. Therefore delegation + CTV + APO may be sufficient for making chaperone signatures work, if they are desired by a user. Remarks: APO's design discussion should not revisit Chaperone signatures (hopefully already a dead horse?) but instead consider how APO might compose with Delegation proposals and CTV. -- @JeremyRubin -------------- next part -------------- An HTML attachment was scrubbed... URL: