public inbox for bitcoindev@googlegroups.com
 help / color / mirror / Atom feed
From: jl2012@xbt•hk
To: bitcoin-dev@lists•linuxfoundation.org
Subject: [bitcoin-dev] The use of tx version field in BIP62 and 68
Date: Sat, 08 Aug 2015 14:51:17 -0400	[thread overview]
Message-ID: <bcebe52e7f66f2065d48e089d773156b@xbt.hk> (raw)

BIP68 rules and some of the BIP62 rules are applied only if the tx 
version is >=2 and >=3 respectively. Therefore, it is not possible to 
create a tx which follows BIP62 but not BIP68. If we introduce v4 tx 
later, BIP62 and BIP68 will all become mandatory.

Some rules, e.g. "scriptPubKey evaluation will be required to result in 
a single non-zero value" in BIP62, will cause trouble when we try to 
introduce a new script system with softfork.

I suggest to divide the tx version field into 2 parts: the higher 4 bits 
and lower 28 bits.

BIP62 is active for a tx if its highest bits are 0000, and the second 
lowest bit is 1.

BIP68 is active for a tx if its highest bits are 0000, and the third 
lowest bit is 1.

So it will be easier for us to re-purpose the nSequence, or to take 
advantage of malleability in the future. If this is adopted, the 
nSequence high bit requirement in BIP68 becomes unnecessary as we could 
easily switch it off.

The low bits will allow 28 independent BIPs and should be ample for many 
years. When they are exhausted, we can switch the high bits to a 
different number (1-15) and redefine the meaning of low bits. By that 
time, some of the 28 BIPs might have become obsoleted or could be 
merged.

(I'm not sure if there are other draft BIPs with similar interpretation 
of tx version but the comments above should also apply to them)


             reply	other threads:[~2015-08-08 18:51 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-08-08 18:51 jl2012 [this message]
2015-08-08 18:56 ` Mark Friedenbach
2015-08-08 19:18   ` jl2012

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=bcebe52e7f66f2065d48e089d773156b@xbt.hk \
    --to=jl2012@xbt$(echo .)hk \
    --cc=bitcoin-dev@lists$(echo .)linuxfoundation.org \
    /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