From subhra.mazumdar1993 at gmail.com Mon Jan 27 04:23:16 2020 From: subhra.mazumdar1993 at gmail.com (Subhra Mazumdar) Date: Mon, 27 Jan 2020 09:53:16 +0530 Subject: [Lightning-dev] Reduce the amount of collateral locked by scripts for transferring funds in lightning network In-Reply-To: References: Message-ID: Hi ZmnSCPxj, It is stated in the paper "Atomic multi-channel updates with constant collateral in bitcoin-compatible payment-channel networks" and I am quoting verbatim (page 11) (last email still waiting moderator approval) "Phase I: Setup. The first phase requires to freeze the coins available at each channel involved in the protocol. Doing this naively (i.e., locking the complete balance in the channel at once) would lock more coins than required, unnecessarily increasing the collateral in the protocol. Instead, during the setup phase, the balance at each payment channel is split in two, effectively creating thereby two sub-channels: one sub-channel is set with the coins required for the present protocol session, while the other one is set with the remaining coins, which can then be freely spent. In the illustrative example shown in Figure 4.2, the setup phase starts with the user A collaborating with user B to create the transaction Tx A setup , where they split the 10 coins they have in the channel in two sub-channels: one sub-channel with 8 coins to be used in the rest of the protocol session and one sub-channel with the rest (i.e., 2 coins). This transaction is signed by both users so that it can be eventually enforced on-chain if required. The rest of the users behave analogously. Note that operations at each channel in this phase of the protocol can be carried out in parallel." Does this sound good ? On Mon, Jan 27, 2020 at 9:41 AM Subhra Mazumdar < subhra.mazumdar1993 at gmail.com> wrote: > Hi ZmnSCPxj, > It is stated in the paper "Atomic multi-channel updates with > constant collateral in bitcoin-compatible payment-channel networks". I am > attaching the screenshot of the paragraph which mentions about locking the > amount which is required for payment transfer and not the entire channel > fund. > > On Mon, Jan 27, 2020 at 6:15 AM ZmnSCPxj wrote: > >> Good morning Subhra, >> >> This does not seem to make sense? >> For a payment that is less than the channel funds on your side, only that >> amount is locked behind an HTLC, and the rest remains useable for other >> HTLCs. >> >> What exactly are you referring to? >> >> Regards, >> ZmnSCPxj >> >> > Hi, >> > I was wondering when parties apply condition on fraction of >> channel fund for ensuring successful payment, entire channel fund is held. >> Is it possible to lock just partial amount of fund of a payment channel and >> leave the rest to be used by some another payment request ? Concept of >> subchannels of a single channel has been suggested in "Atomic multi-channel >> updates with constant collateral in bitcoin-compatible payment-channel >> networks" >> https://scholar.google.com/scholar?cluster=40566801298747858&hl=en&as_sdt=2005&sciodt=0,5 >> but I am still in doubt what happens during closing of subchannel ? >> > -- >> > Yours sincerely, >> > Subhra Mazumdar. >> >> >> > > -- > Yours sincerely, > Subhra Mazumdar. > > -- Yours sincerely, Subhra Mazumdar. -------------- next part -------------- An HTML attachment was scrubbed... URL: