On Mar-26, SuperTestnet
introduced a new protocol for two-party payment channels. He called the protocol
HedgeHog. The dev says that Hedgehog channels are similar to lightning channels but with a few comparative benefits.
Let me explain how I understood it based on the sources, the links to which are provided above. If I am wrong, please correct me.
The main difference between HedgeHog and Lightning lies in replacing pre-signed transactions with transactions revocable via connectors. HedgeHog allows for offline money transfers using connector outputs. The validity of a transaction is determined by the existence of a UTXO, which is an input into that transaction.
Within HedgeHog channels, it's possible to create pools of coins (allocating shares in the channel to pool participants on a federated basis):
- As long as at least one pool key holder is honest, the pool cannot steal users' funds.
- Adding a user to the pool does not require on-chain transactions.
- Money transfers within the pool do not require anyone to pay a commission.
- Users have the ability to issue off-chain vouchers, which are valid for anyone, even non-members of the pool. Vouchers can be transferred in any convenient way (via email, on paper, etc.). Receiving satoshis through such a voucher does not require the recipient to have incoming liquidity, as the check effectively transfers a share in the common channel, and liquidity in it does not change during check operations.
The pool is a multisig n-of-n. Its weakness is that all key owners must be online for the pool to function. That's why in case of dishonest behavior by federation members, one honest participant can halt the pool. In this case, all funds in it will have to be withdrawn on-chain.
It can be said that the pool is something like a sidechain, but unlike the well-known Liquid sidechain, where 11 out of 15 federation members can agree to seize others' bitcoins, here everyone will have to agree. Without consensus, disposing of others' funds is impossible.
Transfers between HedgeHog and Lightning Network are possible.
Overall, the idea is commendable. Currently, HedgeHog only operates in Mutiny Signet. But, it seems that nothing prevents it from eventually being deployed on the main network.
