Re: [bitcoin-dev] [BIP-draft] CHECKSEQUENCEVERIFY - An opcode for relative locktime

[jl2012@xbt.hk]

Gregory Maxwell via bitcoin-dev 於 2015-08-23 21:01 寫到:

> 
> Seperately, to Mark and Btcdrank: Adding an extra wrinkel to the
> discussion has any thought been given to represent one block with more
> than one increment?  This would leave additional space for future
> signaling, or allow, for example, higher resolution numbers for a
> sharechain commitement.
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I think this comment is more related to BIP68 instead of OP_CSV? Without 
further complicating the BIP68, I believe the best way to leave room for 
improvement is to spend a bit in tx nVersion to indicate the activation 
of BIP68. I have raised this issue before with 
http://lists.linuxfoundation.org/pipermail/bitcoin-dev/2015-August/010043.html 
However, it seems Mark isn't in favor of my proposal

The idea is not to permanently change the meaning of nSequence. 
Actually, BIP68 is "only enforced if the most significant bit of the 
sequence number field is set." So BIP68 is optional, anyway. All I 
suggest is to move the flag from nSequence to nVersion. However, this 
will leave much bigger room for using nSequence for other purpose in the 
future.

AFAIK, nSequence is the only user definable and signed element in TxIn. 
There could be more interesting use of this field and we should not 
change its meaning permanently. (e.g. if nSequence had 8 bytes instead 
of 4 bytes, it could be used to indicate the value of the input to fix 
this problem: https://bitcointalk.org/index.php?topic=181734.0 )