public inbox for bitcoindev@googlegroups.com
 help / color / mirror / Atom feed
From: "David A. Harding" <dave@dtrt•org>
To: Andrew Poelstra <apoelstra@wpsoftware•net>
Cc: Matthew Zipkin <pinheadmz@gmail•com>,
	Ethan Heilman <eth3rs@gmail•com>,
	Bitcoin Development Mailing List <bitcoindev@googlegroups.com>
Subject: Re: [bitcoindev] Signing a Bitcoin Transaction with Lamport Signatures (no changes needed)
Date: Mon, 06 May 2024 18:11:48 -1000	[thread overview]
Message-ID: <93b8ed39b0aa3955eb9cb99f9fc5aae9@dtrt.org> (raw)
In-Reply-To: <ZjkqIzPSFLc0GJJ1@camus>

On 2024-05-06 09:06, Andrew Poelstra wrote:
> You can implement ECDSA. It will just take a *lot* of opcodes.

I'll accept that as a given, but how do you know that a given ECDSA 
signature actually commits to the transaction that contains it if 
OP_CHECKSIG only operates on fixed-size schnorr signatures?

Is this what you're describing: if the controlling signature is a 
lamport signature that commits to an ECDSA signature, it's safe to 
disclose the private key for the ECDSA signature; when you don't have to 
worry about private key disclosure, it's safe to construct a schnorr 
signature that uses the same private key, nonce, and message commitment 
as the ECDSA signature; if that schnorr signature makes OP_CHECKSIG 
return true, then you know the message is the current transaction?

That still leaves me confused.  If ECDSA can be implemented within 
tapscript, then I would expect that schnorr could also be implemented 
within tapscript; that gives you an OP_CSFS equivalent.  If being able 
to implement ECDSA in tapscript allows introspection, then I would 
expect implementing schnorr in tapscript would allow introspection; that 
gives you an OP_CAT equivalent.  If you have OP_CSFS and OP_CAT, you 
have covenants and there's no need for lamport signatures or ECDSA.

Apologies for my remaining confused in the face of something that's 
probably obvious,

-Dave





-- 
You received this message because you are subscribed to the Google Groups "Bitcoin Development Mailing List" group.
To unsubscribe from this group and stop receiving emails from it, send an email to bitcoindev+unsubscribe@googlegroups•com.
To view this discussion on the web visit https://groups.google.com/d/msgid/bitcoindev/93b8ed39b0aa3955eb9cb99f9fc5aae9%40dtrt.org.


  parent reply	other threads:[~2024-05-07  8:43 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-04-29  0:30 Ethan Heilman
2024-04-30 12:32 ` Matthew Zipkin
2024-04-30 13:25   ` Ethan Heilman
2024-04-30 14:21   ` Andrew Poelstra
2024-04-30 20:43     ` Ethan Heilman
2024-05-01  3:46       ` Antoine Riard
2024-05-01 20:02         ` Ethan Heilman
2024-05-06  7:39     ` David A. Harding
2024-05-06 16:48       ` Andrew Poelstra
2024-05-06 18:56         ` David A. Harding
2024-05-06 19:06           ` Andrew Poelstra
2024-05-07  0:55             ` Antoine Riard
2024-05-07 16:05               ` Ethan Heilman
2024-05-07  4:11             ` David A. Harding [this message]
2024-05-07 14:34               ` Andrew Poelstra
2024-05-09  0:31     ` Ben Carman
2024-05-09 12:46       ` Andrew Poelstra
2024-05-11  2:53         ` Antoine Riard

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=93b8ed39b0aa3955eb9cb99f9fc5aae9@dtrt.org \
    --to=dave@dtrt$(echo .)org \
    --cc=apoelstra@wpsoftware$(echo .)net \
    --cc=bitcoindev@googlegroups.com \
    --cc=eth3rs@gmail$(echo .)com \
    --cc=pinheadmz@gmail$(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