Garrison: A Novel Watchtower Scheme for Bitcoin.

In this paper, we propose Garrison, which is a payment channel with watchtower for Bitcoin. For this scheme, the storage requirements of both channel parties and their watchtower would be O(log(N)) with N being the number of channel updates. Furthermore, using properties of the adaptor signature, Garrison avoids state duplication. It means both parties store the same version of transactions for each state and hence the number of off-chain transactions does not exponentially increase with the number of applications built on top of each other in the channel. Moreover, the new proposal avoids punish-per-output pattern, meaning that all outputs of a revoked state can be claimed using a single revocation transaction. Garrison can be implemented without any update in Bitcoin script.