Message-ID: <1c32b9c17a7a3ad6646994335c69155b65ac4f8f.camel@timruffing.de>
From: Tim Ruffing <crypto@timruffing.de>
To: bitcoin-dev@lists.linuxfoundation.org
Date: Wed, 11 Oct 2023 22:52:52 +0200
In-Reply-To: <56677685-619a-691f-d5bc-54b69fdb6ed2@bip324.com>
References: <56677685-619a-691f-d5bc-54b69fdb6ed2@bip324.com>
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Cc: Dhruv M <dhruv@bip324.com>
Subject: Re: [bitcoin-dev] Refreshed BIP324
Precedence: list

Hello,

We'd like to announce two recent updates to BIP324 ("Version 2 P2P
Encrypted Transport Protocol"). Some of these changes affect semantics
and some are backwards-incompatible.

While we are not aware of any implementations of BIP324 except the one
in Bitcoin Core (see https://github.com/bitcoin/bitcoin/issues/27634 ),
the purpose of the email is to inform anyone involved in other
implementation efforts. At this point, we don't expect any further
backwards-incompatible changes.

https://github.com/bitcoin/bips/pull/1496 did multiple small changes:
 * Incoming v1 connections are now detected based on first 16 bytes
   they sent (instead of 12), which improves accuracy. If the incoming
   v1 connection appears to come from a wrong network (due to non-
   matching "network magic" bytes), responders may now drop the
   connection immediately.
 * The BIP330 message types have been dropped from the short encodings
   list in the BIP. It feels like it shouldn't be BIP324's goal to
   predict future protocol improvements.

https://github.com/bitcoin/bips/pull/1498 introduced a backwards-
incompatible change:
 * The garbage authentication packet is removed by merging it with the
   version packet. This simplifies the protocol implementation by
   consolidating the states and removing the special case of "ignoring
   the ignore bit." The freedom to choose the contents of the garbage
   authentication packet has also been removed, leading to easier
   testing and implementation.

We also did some editorial improvements. The most recent revision of
the BIP324 can be found at:=C2=A0

https://github.com/bitcoin/bips/blob/master/bip-0324.mediawiki

Best,
Dhruv, Tim, and Pieter

On Sat, 2022-10-08 at 12:59 +0000, Dhruv M wrote:
> Hi all,
>=20
> We have refreshed the proposal for BIP324, a new bitcoin P2P protocol
> featuring opportunistic encryption, a mild bandwidth reduction, and
> the
> ability
> to negotiate upgrades before exchanging application messages. We'd
> like
> to invite community members to review the BIP[1] and the related
> Bitcoin
> Core
> code[2].
>=20
> The proposal has a rich history[3]. The big changes since the last
> public
> appearance[4] are:
>=20
> * Elligator-swift encoding for the pubkeys in the ECDH exchange to
> obtain a pseudorandom bytestream
> * x-only ECDH secret derivation
> * Transport versioning that allows for upgradability
> * Trafic shapability using decoy packets and a shapable handshake
> * Complete rewrite of the BIP text
>=20
> We look forward to your review and comments.
>=20
> -Dhruv, Tim and Pieter
>=20
>=20
> [1] BIP Pull Request: https://github.com/bitcoin/bips/pull/1378
>=20
> [2] All historical and current PRs:
> https://bip324.com/sections/code-review/
>=20
> [3] https://bip324.com/sections/bip-review/
>=20
> [4] https://gist.github.com/dhruv/5b1275751bc98f3b64bcafce7876b489
>=20
>=20
>=20