From: Arthur Chen <arthur.chen@btcc•com>
To: Jonas Schnelli <dev@jonasschnelli•ch>,
Bitcoin Protocol Discussion
<bitcoin-dev@lists•linuxfoundation.org>
Subject: Re: [bitcoin-dev] BIP 151 use of HMAC_SHA512
Date: Tue, 28 Jun 2016 16:31:51 +0800 [thread overview]
Message-ID: <CAP+0UNKqDknS-w6QyCJ0_ra71YfsDDtSdSBYoguUicW2oNMLvQ@mail.gmail.com> (raw)
In-Reply-To: <577224E8.6070307@jonasschnelli.ch>
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Based on previous crypto analysis result, the actual security of SHA512 is
not significantly higher than SHA256.
maybe we should consider SHA3?
On Tue, Jun 28, 2016 at 3:19 PM, Jonas Schnelli via bitcoin-dev <
bitcoin-dev@lists•linuxfoundation.org> wrote:
> > To quote:
> >
> >> HMAC_SHA512(key=ecdh_secret|cipher-type,msg="encryption key").
> >>
> >> K_1 must be the left 32bytes of the HMAC_SHA512 hash.
> >> K_2 must be the right 32bytes of the HMAC_SHA512 hash.
> >
> > This seems a weak reason to introduce SHA512 to the mix. Can we just
> > make:
> >
> > K_1 = HMAC_SHA256(key=ecdh_secret|cipher-type,msg="header encryption
> key")
> > K_2 = HMAC_SHA256(key=ecdh_secret|cipher-type,msg="body encryption key")
>
> SHA512_HMAC is used by BIP32 [1] and I guess most clients will somehow
> make use of bip32 features. I though a single SHA512_HMAC operation is
> cheaper and simpler then two SHA256_HMAC.
>
> AFAIK, sha256_hmac is also not used by the current p2p & consensus layer.
> Bitcoin-Core uses it for HTTP RPC auth and Tor control.
>
> I don't see big pros/cons for SHA512_HMAC over SHA256_HMAC.
>
> </jonas>
>
> [1]
>
> https://github.com/bitcoin/bips/blob/master/bip-0032.mediawiki#child-key-derivation-ckd-functions
>
>
> _______________________________________________
> bitcoin-dev mailing list
> bitcoin-dev@lists•linuxfoundation.org
> https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev
>
>
--
Xuesong (Arthur) Chen
Senior Principle Engineer
BlockChain Technologist
BTCC
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next prev parent reply other threads:[~2016-06-28 8:31 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-28 2:31 Rusty Russell
2016-06-28 7:17 ` [bitcoin-dev] BIP 151 Eric Voskuil
2016-06-28 8:26 ` Jonas Schnelli
2016-06-28 16:45 ` Eric Voskuil
2016-06-28 18:22 ` Peter Todd
2016-06-28 18:35 ` Eric Voskuil
2016-06-28 20:14 ` Peter Todd
2016-06-28 20:29 ` Eric Voskuil
2016-06-28 20:36 ` Peter Todd
2016-06-28 21:22 ` Eric Voskuil
2016-06-28 21:36 ` Gregory Maxwell
2016-06-28 21:40 ` Cameron Garnham
2016-06-28 22:07 ` Eric Voskuil
2016-06-28 22:33 ` Cameron Garnham
2016-06-28 23:29 ` Eric Voskuil
2016-06-29 0:06 ` Nick ODell
2016-06-28 21:59 ` Eric Voskuil
[not found] ` <CAAS2fgQ0Ocs8hF+pf+fWfkKKhQwxNKpY=JHpb_bwua7neVO8tg@mail.gmail.com>
2016-06-28 23:34 ` Eric Voskuil
2016-06-28 20:06 ` Jonas Schnelli
2016-06-28 23:31 ` Eric Voskuil
2016-06-29 11:17 ` Alfie John
2016-06-30 11:56 ` Eric Voskuil
2016-06-30 12:20 ` Jonas Schnelli
2016-06-30 12:27 ` Eric Voskuil
2016-06-30 12:43 ` Jonas Schnelli
2016-06-30 15:22 ` Eric Voskuil
2016-06-30 16:52 ` Peter Todd
2016-06-30 18:25 ` Eric Voskuil
2016-06-30 19:06 ` Peter Todd
2016-06-30 20:26 ` Eric Voskuil
2016-06-28 19:55 ` Gregory Maxwell
2016-06-28 23:33 ` Eric Voskuil
2016-06-29 1:01 ` Gregory Maxwell
2016-06-30 9:57 ` Eric Voskuil
2016-06-30 13:03 ` Pieter Wuille
2016-06-30 15:10 ` Eric Voskuil
2016-08-31 14:29 ` Pieter Wuille
2016-06-30 13:36 ` Erik Aronesty
2016-06-30 14:47 ` Alfie John
2016-07-02 9:44 ` Chris Priest
2016-06-28 12:13 ` Jonas Schnelli
2016-06-28 17:39 ` Eric Voskuil
2016-06-28 7:19 ` [bitcoin-dev] BIP 151 use of HMAC_SHA512 Jonas Schnelli
2016-06-28 8:31 ` Arthur Chen [this message]
2016-06-29 18:34 ` Jonas Schnelli
2016-06-29 20:13 ` Peter Todd
2016-06-29 20:31 ` Jonas Schnelli
2016-06-29 1:00 ` Rusty Russell
2016-06-29 1:38 ` Arthur Chen
2016-06-29 1:56 ` Ethan Heilman
2016-06-29 6:58 ` Pieter Wuille
2016-06-29 14:38 ` Ethan Heilman
2016-06-29 18:46 ` Jonas Schnelli
2016-07-01 3:25 ` Rusty Russell
2016-07-01 22:42 ` Zooko Wilcox
2016-07-04 1:23 ` Arthur Chen
2016-07-04 1:44 ` Arthur Chen
2016-07-04 6:47 ` Jonas Schnelli
2016-07-04 6:37 ` Jonas Schnelli
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