I'm going to give a short talk (and even a little practical demonstration) of PathCoin. Later hopefully a more tech deep dive side session. Looking forward to it.
[SPEAKER ANNOUNCEMENT]
[ANUNCIO DE ORADOR]
Adam Gibson aka waxwing is a Bitcoin privacy researcher and developer of Joinmarket, a CoinJoin implementation aimed at improving the privacy and fungibility of bitcoin transactions while giving users the option to earn yield on their bitcoin by providing coinjoin liquidity as a maker.
For more info & tickets 🎟👉
https://adoptingbitcoin.org/2023/speakers/adamgibson
Adam Gibson alias waxwing es un investigador de la privacidad de Bitcoin y desarrollador de Joinmarket, una implementación de CoinJoin destinada a mejorar la privacidad y fungibilidad de las transacciones de bitcoin al tiempo que ofrece a los usuarios la opción de obtener rendimiento de su bitcoin proporcionando liquidez coinjoin como creador.
Para más información y entradas 🎟👉
https://adoptingbitcoin.org/2023/speakers/adamgibson
Las entradas para los salvadoreños cuestan 21 $.
Discussion
https://gist.github.com/AdamISZ/b462838cbc8cc06aae0c15610502e4da ?
That was an interesting read. The single biggest limitation is probably the inability to "skip" part of the path. Otherwise you could repeat the same participants M times, to get arbitrary transfers (with an eye-watering (M * N)^2 efficiency lol).
I was also thinking a bit about spend efficiency, you can probably do better than tap-leaf-per-case (which wasn't explicitly stated, but sort of implied) by compressing multiple CSVs into one tap leaf.
And then finally, I wonder if the "vertical" portion of signature sharing could be compressed by pre-sharing them all, and having some adapter which is constant between them? (guy with only a vague, intuitive understanding of signature adapters)
Just realized my third point probably relies on a construct that doesn't exist, encumbering a musig partial signature with an adapter... but it still seems like sig_A2..AN could be pre-shared as sig'_A2..AN, and alice would send Bob k instead of sig_A2..sig_AN. *hand waves again* You math people figure it out ;-)
Oh that part is for sure a thing, i.e. using adaptors specifically in a musig setting (it works better that way because the adaptor owner is forced to use the pre agreed aggregated nonce). That's how adaptors are used here and in adaptor based atomic swaps etc. Unless maybe I misunderstood what you're saying.
Re tap leaf per case, I realised while coding it that it makes most sense to just have 5 musig signing sessions, on the same aggregated key, rather than 5 tapleafs.
Re: jumping steps, look at my recent post history. With a minir relaxation of 'offlineness', hopping steps on the path is pretty viable.