From 7cc25bfea8b3e00be90f02fda6d1b7b401682eda Mon Sep 17 00:00:00 2001
From: Dr Maxim Orlovsky <orlovsky@pandoracore.com>
Date: Mon, 15 Nov 2021 10:25:50 +0100
Subject: [PATCH] Bifrost: multipeer channel draft

---
 lnpbp-0053.md | 74 +++++++++++++++++++++++++++++++++++++++++++++++++++
 lnpbp-0055.md |  2 +-
 2 files changed, 75 insertions(+), 1 deletion(-)
 create mode 100644 lnpbp-0053.md

diff --git a/lnpbp-0053.md b/lnpbp-0053.md
new file mode 100644
index 0000000..3f93a25
--- /dev/null
+++ b/lnpbp-0053.md
@@ -0,0 +1,74 @@
+```
+LNPBP: 0053
+Layer: OSI Application (i7)
+Vertical: Lightning network protocol
+Title: Muli-peer payment channels for Bifrost
+Author: Dr Maxim Orlovsky <orlovsky@lnp-bp.org>
+Comments-URI: https://github.com/LNP-BP/lnpbps/pulls/97
+Status: Draft
+Type: Standards Track
+Created: 2021-11-14
+Finalized: not yet
+License: CC0-1.0
+```
+
+## Abstract
+
+## Background
+
+## Motivation
+
+## Design
+
+## Specification
+
+### Messaging
+
+
+### Funding transaction
+
+Transaction containing multiple inputs, each of which MUST signal S2C commitment type.
+
+Output descriptor: `tr(musig(KEY_LOCAL_FUNDING, KEY_REMOTE_FUNDING))`
+
+
+### Commitment transaction
+
+Input:
+- Spends funding output
+- nSeq: `0x80800000 + COMMITMENT_NO & 0xFFFF` (signals S2C DBC)
+- Witness stack:
+  - `KEY_LOCAL_FUNDING + KEY_REMOTE_FUNDING`
+  - `SIG*(KEY_LOCAL_FUNDING + KEY_REMOTE_FUNDING)`
+  where * denotes optional presence of sign-to-contract commitment
+
+Outputs:
+- "To local": `tr(KEY_REVOCATION, and_v(v:pk(KEY_LOCAL),older(SELF_DELAY)))`
+  * `KEY_LOCAL`: proposed by the local node
+  * `SELF_DELAY`: proposed by the remote node, may be rejected by local
+- "To remote": `tr(musig(KEY_LOCAL, KEY_REMOTE), and_v(v:pk(KEY_REMOTE),older(REMOTE_DELAY))`
+  * `KEY_LOCAL`: proposed by the local node
+  * `KEY_REMOTE`: propsoed by the remote node
+  * `REMOTE_DELAY`: proposed by the local node, may be rejected by remote
+- "Anchor": `tr(musig(KEY_LOCAL, KEY_REMOTE), {v:pk(KEY_LOCAL), v:pk(KEY_REMOTE)})`
+  * `KEY_LOCAL`: proposed by the local node
+  * `KEY_REMOTE`: propsoed by the remote node
+  * The ooutput must contain a fixed amount of satoshis above dust limit proposed by
+    the node adding this output to the channel proposal
+
+
+## Compatibility
+
+## Rationale
+
+## Reference implementation
+
+## Acknowledgements
+
+## References
+
+## Copyright
+
+This document is licensed under the Creative Commons CC0 1.0 Universal license.
+
+## Test vectors
diff --git a/lnpbp-0055.md b/lnpbp-0055.md
index caee153..6b90b11 100644
--- a/lnpbp-0055.md
+++ b/lnpbp-0055.md
@@ -121,7 +121,7 @@ The input of *HTLC spending transactions* spends *offered HTLC* (for *HTLC timeo
   - 0 for HTLC-success
   - `CLTV_EXPIRY` for HTLC-timeout
 - Input:
-  - nSeq: `SELF_DELAY` (must be odd to use P2C deterministic bitcoin commitments)
+  - nSeq: `SELF_DELAY` (must be even to use P2C deterministic bitcoin commitments)
   - control block: `0xC0/0xC1 <first branch tapleaf-hash>`
   - rest of witness stack for *HTLC-success*:
     - `KEY_HTLC_LOCAL`