public inbox for bitcoindev@googlegroups.com
 help / color / mirror / Atom feed
From: William Yager <will.yager@gmail.com>
To: Pavol Rusnak <stick@gk2.sk>
Cc: Bitcoin Dev <bitcoin-development@lists.sourceforge.net>
Subject: Re: [Bitcoin-development] [RFC] Proposal: Base58 encoded HD Wallet root key with optional encryption
Date: Wed, 12 Mar 2014 15:49:43 -0500	[thread overview]
Message-ID: <CAG8oi1Mac8TozHaVQF_BWLFp_EdA_VF3aEs1aALhA3Wpvmfusw@mail.gmail.com> (raw)
In-Reply-To: <5320C6C7.9040602@gk2.sk>

[-- Attachment #1: Type: text/plain, Size: 1352 bytes --]

On Wed, Mar 12, 2014 at 3:42 PM, Pavol Rusnak <stick@gk2.sk> wrote:

> On 03/12/2014 09:37 PM, William Yager wrote:
> > (that group of people includes me), PBKDF2-HMAC-SHA512 is very easy to
> > implement even on devices that only have a few kB of RAM, and even though
> > our number of rounds is very aggressive (2^16 and 2^21), it will still
> run
> > in reasonable time even on very slow embedded ARM processors.
>
> To give you some numbers: TREZOR (120MHz ARM) does 1024 rounds of
> PBKDF2-HMAC-SHA512 in around 1 second.
>
> So 2^16 is around one minute, 2^21 is around half an hour.
>
>
Precisely. And since the target of this BIP is generally storage wallets
(just like BIP 0038), we figured these were reasonable time scales for
encryption/decryption on slow devices.

Let's say you're implementing a Raspberry Pi based cold wallet printer.
Having the user wait 10 seconds to several minutes is not unreasonable for
a one-time activity, especially when at least this much time is used to
generate entropy, print the wallet, etc.

The same goes for phones. If you're importing a heavily encrypted wallet
into your device, the user won't mind waiting a few seconds or even a few
minutes.

Plus, as an added bonus, the amount of time it will take to encrypt/decrypt
is highly deterministic, so it's easy to add a nice progress bar to a UI.

Will

[-- Attachment #2: Type: text/html, Size: 1892 bytes --]

  reply	other threads:[~2014-03-12 20:49 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <op.w0hd2nthyldrnw@laptop-air>
2013-07-19 18:15 ` [Bitcoin-development] [RFC] Proposal: Base58 encoded HD Wallet master seed with optional encryption Jean-Paul Kogelman
2013-07-22 13:14   ` Mike Hearn
2013-07-22 14:33     ` Jean-Paul Kogelman
2013-07-22 21:37     ` Jean-Paul Kogelman
2013-11-16  2:47       ` Gregory Maxwell
2013-11-16  3:09         ` Jean-Paul Kogelman
2013-12-26 11:48           ` Jean-Paul Kogelman
2014-03-12  3:17             ` [Bitcoin-development] [RFC] Proposal: Base58 encoded HD Wallet root key " Jean-Paul Kogelman
2014-03-12 13:11               ` Pavol Rusnak
2014-03-12 15:45                 ` Jean-Paul Kogelman
2014-03-12 15:55                   ` Pavol Rusnak
2014-03-12 16:49                     ` Gary Rowe
2014-03-12 18:00                       ` William Yager
2014-03-12 19:35                       ` Jean-Paul Kogelman
2014-03-12 19:41                         ` Gary Rowe
2014-03-12 19:26                     ` Jean-Paul Kogelman
2014-03-12 19:39                       ` Pavol Rusnak
2014-03-12 19:55                         ` William Yager
2014-03-12 20:04                           ` Pavol Rusnak
2014-03-12 20:10                             ` William Yager
2014-03-12 20:24                               ` Pavol Rusnak
2014-03-12 20:37                                 ` William Yager
2014-03-12 20:42                                   ` Pavol Rusnak
2014-03-12 20:49                                     ` William Yager [this message]
2014-03-12 21:08                                 ` Jean-Paul Kogelman
2014-03-12 21:15                                   ` William Yager
2014-04-22  0:05 William Yager
2014-04-24 19:39 ` William Yager

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=CAG8oi1Mac8TozHaVQF_BWLFp_EdA_VF3aEs1aALhA3Wpvmfusw@mail.gmail.com \
    --to=will.yager@gmail.com \
    --cc=bitcoin-development@lists.sourceforge.net \
    --cc=stick@gk2.sk \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
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