From: Kalle Rosenbaum <kalle@rosenbaum•se>
To: "Jorge Timón" <jtimon@jtimon•cc>
Cc: bitcoin-dev <bitcoin-dev@lists•linuxfoundation.org>
Subject: Re: [bitcoin-dev] [Bitcoin-development] BIP for Proof of Payment
Date: Sun, 26 Jul 2015 23:13:49 +0200 [thread overview]
Message-ID: <CAPswA9yYOzehfd=UxV+EmNOSZnY9nif2Y1GZ_FEy7r5UdzGA0g@mail.gmail.com> (raw)
In-Reply-To: <CABm2gDrickFojwmUi7GqAhSW5K0yTa_59VjKrY+wAXEq1MYUoA@mail.gmail.com>
(Resending to the new bitcoin-dev list after sending to the old list)
2015-07-25 21:34 GMT+02:00 Jorge Timón <jtimon@jtimon•cc>:
> Then why do you assume they have a policy limit that not even bitcoin core
> itself maintains (the default limit was moved from 42 to 83 [counting the
> op_return and pushes])?
>
> The policy check is not a consensus rule. Other implementations may have
> another default or not have a limit at all.
Thank you for pointing this out.
That's right. Bitcoin core now support 80 bytes data by default. And
yes, I was wrong in assuming 40 bytes policy in all implementations,
even if 40 bytes was the limit in bitcoin core at the time of writing
the BIP.
If there's a need to increase the size of the nonce, for example to
128 bits instead of the 48 bits as designed in BIP 120, then we can of
course do that, either now or in a subsequent version of PoP.
As noted before though, a longer nonce also means bigger QR codes
generated from the BIP 121 URIs. So I think that 48 bits is a good
tradeoff right now. And as stated in BIP120, a server generating PoP
requests should try to detect brute force attacks, or at least delay
the response (containing the nonce) by some 100 ms or so.
Do you think we need a bigger nonce? In that case, why?
If PoP later becomes an extension of BIP70, then there is no such size
constraint on the nonce, since it will be part of some kind of (e.g.)
PopRequest message and not contained in a QR encoded URI.
/Kalle
next prev parent reply other threads:[~2015-07-26 21:13 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-06 14:35 Kalle Rosenbaum
2015-06-06 14:47 ` Pieter Wuille
2015-06-06 15:05 ` Kalle Rosenbaum
2015-06-06 15:13 ` Pieter Wuille
2015-06-06 16:20 ` Kalle Rosenbaum
2015-06-06 16:10 ` Tom Harding
2015-06-06 17:00 ` Kalle Rosenbaum
2015-06-06 21:25 ` Kalle Rosenbaum
2015-06-06 22:01 ` Luke Dashjr
2015-06-15 9:21 ` Kalle Rosenbaum
[not found] ` <CAPg+sBiWykR6RaHhbyYQbL=A5t1TmHgEmS_sC7jj9d3SUTMO9g@mail.gmail.com>
[not found] ` <CAPswA9zycU0pwZKaHU9J3Tvg=ovLJ8TZ9OH6ebTPONaRaiOE8g@mail.gmail.com>
2015-06-15 10:00 ` Pieter Wuille
2015-06-15 11:59 ` Kalle Rosenbaum
2015-06-16 14:31 ` Pieter Wuille
2015-06-16 19:22 ` Kalle Rosenbaum
2015-06-16 19:25 ` Pieter Wuille
[not found] ` <CAPswA9yFUAqFyNBFBnnwpT=B9RcdNssdjz-_KWbX5GuLM5Uyxw@mail.gmail.com>
2015-06-16 19:48 ` Pieter Wuille
2015-06-17 9:51 ` Kalle Rosenbaum
2015-06-21 14:39 ` Kalle Rosenbaum
[not found] ` <CAPswA9w8QaWV72UuGnitWWeDTr5MPKvzwrD5udmq_FQke-NGAQ@mail.gmail.com>
2015-07-24 6:55 ` [bitcoin-dev] " Kalle Rosenbaum
2015-07-27 8:14 ` Sriram Karra
[not found] ` <CABm2gDrickFojwmUi7GqAhSW5K0yTa_59VjKrY+wAXEq1MYUoA@mail.gmail.com>
2015-07-26 21:13 ` Kalle Rosenbaum [this message]
2015-07-27 9:08 ` Jorge Timón
2015-07-27 11:21 ` Kalle Rosenbaum
2015-06-16 5:26 ` Tom Harding
2015-06-16 12:12 ` Kalle Rosenbaum
2015-06-16 12:31 ` Kalle Rosenbaum
2015-06-16 14:05 ` Tom Harding
2015-06-16 16:22 ` Kalle Rosenbaum
2015-06-06 15:18 ` Luke Dashjr
2015-06-06 15:23 ` Pieter Wuille
2015-06-06 15:32 ` Peter Todd
2015-06-06 16:35 ` Kalle Rosenbaum
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='CAPswA9yYOzehfd=UxV+EmNOSZnY9nif2Y1GZ_FEy7r5UdzGA0g@mail.gmail.com' \
--to=kalle@rosenbaum$(echo .)se \
--cc=bitcoin-dev@lists$(echo .)linuxfoundation.org \
--cc=jtimon@jtimon$(echo .)cc \
/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