From: Jonas Schnelli <dev@jonasschnelli•ch>
To: Elichai Turkel <elichai.turkel@gmail•com>,
Bitcoin Protocol Discussion
<bitcoin-dev@lists•linuxfoundation.org>
Subject: Re: [bitcoin-dev] New BIP - v2 peer-to-peer message transport protocol
Date: Mon, 17 Jun 2019 18:20:32 +0200 [thread overview]
Message-ID: <76890B69-2004-41C4-B4E7-0C5D070142C3@jonasschnelli.ch> (raw)
In-Reply-To: <CALN7hCKheiE374S6wOMJSTufmuQFxa-d_0x_aJbEPT=KuDc0nw@mail.gmail.com>
[-- Attachment #1: Type: text/plain, Size: 1032 bytes --]
Hi Elichai
> About the nonce being 64bit. (rfc7539 changed it to 96bit, which djb later calls xchacha)
>
> You suggest that we use the "message sequence number" as the nonce for Chacha20, Is this number randomly generate or is this a counter?
> And could it be reseted without rekeying?
The in BIP324 (v2 message transport protocol) proposed AEAD, ChaCha20Poly1305@Bitcoin [1], uses a „message sequence number“. There is no such thing as random nonce described in the BIP (hence the term „sequence number“). The message sequence number starts with 0 and the max traffic before a rekey must occur is 1GB. A nonce/key reuse is conceptually impossible (of course implementations could screw up at this point).
Using XChaCha20 with the possibility of a random nonce could be done, but I don’t see a reason to use it in our case since the usage of a sequence number as nonce seems perfectly save.
[1] https://gist.github.com/jonasschnelli/c530ea8421b8d0e80c51486325587c52#chacha20-poly1305bitcoin-cipher-suite
[-- Attachment #2: Message signed with OpenPGP --]
[-- Type: application/pgp-signature, Size: 833 bytes --]
next prev parent reply other threads:[~2019-06-17 16:26 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-17 2:06 Elichai Turkel
2019-06-17 16:20 ` Jonas Schnelli [this message]
2019-06-17 17:13 ` Elichai Turkel
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=76890B69-2004-41C4-B4E7-0C5D070142C3@jonasschnelli.ch \
--to=dev@jonasschnelli$(echo .)ch \
--cc=bitcoin-dev@lists$(echo .)linuxfoundation.org \
--cc=elichai.turkel@gmail$(echo .)com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox