Re: [Lightning-dev] Impact of eltoo loss of state

2021-07-27 Thread Jeremy
Just my 2 cents: I think worrying about the size of a resolution during a contested close scenario (too much) is not worth it. Encoding the state needed (e.g., in op_return or whatever) is the safest option because then you guarantee the availability of the closing transaction data in the protocol

Re: [Lightning-dev] Impact of eltoo loss of state

2021-07-27 Thread ZmnSCPxj via Lightning-dev
Good morning aj, and list, > > I don't think you can reliably hide that you forgot some state? Thinking a little more --- *why* do we need to hide that we forgot some state? The reason is that if your peer learns you forgot state, the peer can pass off obsolete state onchain, thereby stealing

Re: [Lightning-dev] Impact of eltoo loss of state

2021-07-27 Thread ZmnSCPxj via Lightning-dev
Good morning cdecker, aj, and list, > . In addition we can store the same data with multiple peers, ensuring that > as long as one node is behaving we're good. Depending on size limits of the stored data, it may be possible to use some kind of erasure coding so that at least k of n peers need

Re: [Lightning-dev] Impact of eltoo loss of state

2021-07-20 Thread Anthony Towns
On Wed, Jul 14, 2021 at 04:44:24PM +0200, Christian Decker wrote: > Not quite sure if this issue is unique to eltoo tbh. While in LN-penalty > loss-of-state equates to loss-of-funds, in eltoo this is reduced to > impact only funds that are in a PTLC at the time of the loss-of-state. Well, the idea

Re: [Lightning-dev] Impact of eltoo loss of state

2021-07-20 Thread Christian Decker
We'd likely be using an HMAC to ensure the integrity of the data returned by peers, so we'd only have to guard against them returning an older version, which in eltoo. Furthermore by retrieving the blobs on reconnect regardless of whether we need them or not we can verify that peers are behaving co

Re: [Lightning-dev] Impact of eltoo loss of state

2021-07-15 Thread Martin Habovštiak
What would happen in 2) if the node has data but the peer returned an incorrect state? On Wed, Jul 14, 2021, 20:13 Christian Decker wrote: > Not quite sure if this issue is unique to eltoo tbh. While in LN-penalty > loss-of-state equates to loss-of-funds, in eltoo this is reduced to > impact onl

Re: [Lightning-dev] Impact of eltoo loss of state

2021-07-14 Thread Christian Decker
Not quite sure if this issue is unique to eltoo tbh. While in LN-penalty loss-of-state equates to loss-of-funds, in eltoo this is reduced to impact only funds that are in a PTLC at the time of the loss-of-state. We have a couple of options here, that don't touch the blockchain, and are therefore r

Re: [Lightning-dev] Impact of eltoo loss of state

2021-07-12 Thread Jeremy
Another option would be to somehow encrypt this data in, say, an OP_RETURN for any update transaction for each participant (perhaps worth breaking update symmetry for efficiency on this...) that way if an update ever happens on a state you don't have you can use your static key to decrypt the relev

Re: [Lightning-dev] Impact of eltoo loss of state

2021-07-12 Thread Jeremy
Without an exact implementation, one thing you could do to fix the lost state issue would be to make the scripts something like: [` CLTV DROP PKu CHECKSIGVERIFY GETLOCKTIME BIP32DERIVE CHECKTRANSACTIONSIGNEDFROMSTACK`, `2016 CSV DROP PK_si CHECKSIG`] In order to upgrade to state M>= N+1 you'd ha

[Lightning-dev] Impact of eltoo loss of state

2021-07-12 Thread Anthony Towns
Hello world, Suppose you have some payments going from Alice to Bob to Carol with eltoo channels. Bob's lightning node crashes, and he recovers from an old backup, and Alice and Carol end up dropping newer channel states onto the blockchain. Suppose the timeout for the payments is a few hours awa