From: "Michael Grønager" <gronager@mac.com>
To: Watson Ladd <wbl@uchicago.edu>
Cc: bitcoin-development@lists.sourceforge.net
Subject: Re: [Bitcoin-development] Proposal for a new opcode
Date: Mon, 5 Mar 2012 15:14:07 +0100 [thread overview]
Message-ID: <6A095CA9-8A01-4578-A660-CED02B24F215@mac.com> (raw)
In-Reply-To: <CACsn0cne5An+SyKDf9w4o4Secn7C9wqqbG7ff0HB3Dvk-XxHRg@mail.gmail.com>
Sounds interesting, however, even after a couple of days, I cannot see how you maintain protection against double spend using OP_CHECKEXPSIG. It is not until you redeem the OP_CHECKEXPSIG transaction that you reveal which former transactions that was involved?
I guess I am missing a point here?
/M
On 02/03/2012, at 20:57, Watson Ladd wrote:
> Dear all,
> I am proposing a new opcode for the purposes of anonymous
> transactions. This new opcode enables scripts to be given proof that
> the receiver can carry out or has carried out a previous transaction.
> I'm currently working on a paper that discusses using this opcode for
> anonymous transactions.
>
> Name: OP_CHECKEXPSIG
> Stack before: <sig><pk><hash>
> Stack after: T/F, where is true if sig is a ECDSA signature under pk
> for the hash hash. (Hash is the hash of a message).
> Uses: Preexisting digital cash techniques relied on keeping track of a
> list of turned in notes to forbid double spending. Using
> OP_CHECKEXPSIG we can instead pass the script that gives the nth note
> value proof that the notes {1,...n-1} were turned in and are distinct.
> This enables a coupling of the strong double spend protection of
> Bitcoin with traditional digital cash's strong anonymity.
>
> Sincerely,
> Watson Ladd
>
> ------------------------------------------------------------------------------
> Virtualization & Cloud Management Using Capacity Planning
> Cloud computing makes use of virtualization - but cloud computing
> also focuses on allowing computing to be delivered as a service.
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next prev parent reply other threads:[~2012-03-05 14:14 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CACsn0c=P1veYnmXe4E3qU0OC=Xr9Aw6Fy=6Zm0sUAaSBEDvpMA@mail.gmail.com>
2012-03-02 19:57 ` [Bitcoin-development] Fwd: Proposal for a new opcode Watson Ladd
2012-03-03 17:55 ` Gavin Andresen
2012-03-05 14:14 ` Michael Grønager [this message]
2012-03-07 0:05 ` Gregory Maxwell
2012-03-07 0:42 ` Watson Ladd
2012-03-21 19:54 ` Gregory Maxwell
[not found] ` <CACsn0cmfwuBpFTTMZ9psOoTKb3ovmAdb=VTSYQ7LJaf8+YzTUg@mail.gmail.com>
2012-03-21 22:02 ` [Bitcoin-development] " Watson Ladd
2012-03-22 0:49 ` Gregory Maxwell
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