Today we have first-eligible-height (nLockTime), and mempool expiration 
measured from this height would work for the goals being discussed, no 
fork or protocol rev.

With first-eligible-height and last-eligible-height, creator could 
choose a lifetime shorter than the max,  and in addition, lock the whole 
thing until some point in the future.


On 8/6/2014 9:15 AM, Jeff Garzik wrote:
> A fork is not necessarily required, if you are talking about 
> information that deals primarily with pre-consensus mempool behavior.  
> You can make a "network TX" with some information that is digitally 
> signed, yet discarded before it reaches miners.
>
>
> On Wed, Aug 6, 2014 at 11:42 AM, Peter Todd <pete@petertodd.org 
> <mailto:pete@petertodd.org>> wrote:
>
>     -----BEGIN PGP SIGNED MESSAGE-----
>     Hash: SHA256
>
>
>
>     On 6 August 2014 08:17:02 GMT-07:00, Christian Decker
>     <decker.christian@gmail.com <mailto:decker.christian@gmail.com>>
>     wrote:
>     >+1 for the new field, overloading fields with new meaning is
>     definitely
>     >not
>     >a good idea.
>
>     To add a new field the best way to do it is create a new,
>     parallel, tx format where fields are committed by merkle radix
>     tree in an extensible and provable way. You'd then commit to that
>     tree with a mandatory OP_RETURN output in the last txout, or with
>     a new merkle root.
>
>     Changing the tx format itself in a hard-fork is needlessly
>     disruptive, and in this case, wastes opportunities for improvement.
>     -----BEGIN PGP SIGNATURE-----
>     Version: APG v1.1.1
>
>     iQFQBAEBCAA6BQJT4kzQMxxQZXRlciBUb2RkIChsb3cgc2VjdXJpdHkga2V5KSA8
>     cGV0ZUBwZXRlcnRvZGQub3JnPgAKCRAZnIM7qOfwhamzCAC+zRaXRodP63+ke3K+
>     Viapiepvk4uIOlqxqtMB2O0zWcyu2+xCJDiRPykK/6HLDBeFDEC9/dGK8++Lovl6
>     //qZ340LOPFlgT2kYy9E5h/yX469fhtsWhBCv2K47fWwkMS0S/0r4SQnCkbt2R2c
>     4dQjkoldhw6rNMBTUmwvhSlL30KsT/msWTZiX7DW/YjfOzezEJzy+mYyKp9Sk7ba
>     1fOiBXORk7mNOs7sTYTvje3sqEGpGTOLP08cY/RCEvl6bG8mHkPqwiojq+3biHFP
>     RsoBVu1f5cbnU7Wq0gPNdVnQssnEQDadyTX8gT0Wze7PuVyaZT2mXFZBKzSHuLy2
>     sJKN
>     =oPSo
>     -----END PGP SIGNATURE-----
>
>
>
>
> -- 
> Jeff Garzik
> Bitcoin core developer and open source evangelist
> BitPay, Inc. https://bitpay.com/
>
>
> ------------------------------------------------------------------------------
> Infragistics Professional
> Build stunning WinForms apps today!
> Reboot your WinForms applications with our WinForms controls.
> Build a bridge from your legacy apps to the future.
> http://pubads.g.doubleclick.net/gampad/clk?id=153845071&iu=/4140/ostg.clktrk
>
>
> _______________________________________________
> Bitcoin-development mailing list
> Bitcoin-development@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/bitcoin-development