From: William Swanson <swansontec@gmail•com>
To: James Poole <james@microtrx•com>
Cc: Bitcoin Dev <bitcoin-development@lists•sourceforge.net>
Subject: Re: [Bitcoin-development] Bip 32 Question
Date: Fri, 12 Jun 2015 12:42:46 -0700 [thread overview]
Message-ID: <CABjHNoR=jrXixMdsESugw=ZgAVc87gJck48ozLT7XcFr4+Zr_g@mail.gmail.com> (raw)
In-Reply-To: <CAN4RR9gRQCEkns21OTCpWmGOftFXbR-cLWuJX805iPjGATmLyQ@mail.gmail.com>
The `n` is the curve order, as shown here:
https://en.bitcoin.it/wiki/Secp256k1
This step is necessary to keep you on the curve. The
secp256k1_ec_privkey_tweak_add function from libsecp256k1 handles this
automatically, but if you use OpenSSL or some non-EC math library, you
probably have to do it yourself.
-William
On Fri, Jun 12, 2015 at 11:22 AM, James Poole <james@microtrx•com> wrote:
> Looking at the BIP32 definition, I hit a line that I would appreciate
> clarification on.
>
> https://github.com/bitcoin/bips/blob/master/bip-0032.mediawiki
>
> Under the section "Private parent key → private child key" there is a step:
>
> "The returned child key ki is parse256(IL) + kpar (mod n)."
>
> Can someone help me understand what "n" is in the context of this algorithm?
> I very well could be looking right at it, but wanted to double check if I am
> missing something.
>
> Thanks,
> James
prev parent reply other threads:[~2015-06-12 19:42 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-12 18:22 James Poole
2015-06-12 19:42 ` William Swanson [this message]
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