HD Wallets have a flaw that revealing a private key and its parent master public key will reveal its parent master private key. (Described here[1] and here[2]).

Isn't there a similar concept with master public key and master private key that does not suffer from this issue. (Does not have to be ECDSA. I just want a deterministic private-public keypair generator that can publish its master public key).

[1] https://bitcoinmagazine.com/8396/deterministic-wallets-advantages-flaw/

[2] https://eprint.iacr.org/2014/998.pdf (chapter 3)

I decided to sell ipadpeek.com domain for Bitcoins in case anyone is interested.

It has 80k monthly visitors, almost of all them are somehow related to iOS/iPhone/iPad because of the content.

Price: 100 BTC.

I created a minimalistic and deterministic version of Bitcoin address generator (from Electrum Master Public Key).

It's based on php-ecc by Matyas Danter and mpkgen by Chris Savery.

The main difference from these two is that it's cleaned up significantly and therefore you need to require just one 7 kB PHP file.
It also requires GMP extension (no BCMath this time), so it's a little bit faster than php-ecc which uses an abstraction layer on top of GMP and BCMath.

I also ported the code to:
* Python - you'll need to have gmpy package installed.
* Ruby - you'll need to have ffi rubygem installed.

The code is MIT licensed and lives here: https://github.com/prusnak/addrgen

I hope this will enable all of you to create your own tipping platforms, eshops and crowdfunding pages. (Most of the software dealing with deterministic wallets was written in Python up to now).

Donations are welcome at 1PuRV7zVXrajGxHJ6LJLccgDYz4hNcVPfS

Thanks!

We just released coinmap 2.0!

https://medium.com/@satoshilabs/the-king-is-dead-long-live-the-king-57beba6f65f6

Try it out at https://coinmap.org/

[print out paper offline Bitcoin wallets]

Hi all!

I would like to introduce a weekend project we did with my friend Split. PaperCoin is a website that provides a very simple way for people to print out paper offline Bitcoin wallets. Once folded, the private key is hidden inside while the address is still visible from the outside. It's a great way for introducing your friends to Bitcoin. All cryptography and PDF creation happens in Javascript in your browser and nothing is sent back to server. You can even download the source code (yes, it's open source!) and run the software locally, if you wish.

Enough babbling, go to http://papercoin.org/ and try for yourself! :-)

This is how the output page and folded wallet look like:



Feedback, ideas and patches are appreciated, of course!

Hi!

I would like to propose the following HTML meta tag for Bitcoin donations. If this idea is accepted, one could create a browser extension that shows the bitcoin icon in the URL bar and user can simply donate to the website by clicking on it (which will launch bitcoin client with pre-filled address).

example:

<meta name="bitcoin" content="1BitkeyP2nDd5oa647AjvBbbwST54W5Zmx" />

What do you think about that? Does it make sense to you?

[monochromatic]

Hi all!

We are in a need of catchy logo for Trezor: Bitcoin Hardware Wallet - see http://trezor.bitcoin.cz/ for more info (atm redirects to its thread on this forum).

Rules:

• submissions must be posted to this thread before Friday 25th January 20:00 UTC
• submissions must contain graphical logo and the text "trezor" or "Trezor" or "TREZOR" (text can be part of the graphical logo)
• submissions must be monochromatic (i.e. containing only black and white color)
• submissions must contain a link to either a SVG vector file (preferred) or a high resolution bitmap (at least 1000x1000 pixels)
• we reserve the right not to pick any submission
• we reserve the right to edit the chosen submission to fit our needs
• by participating in the contest you agree that you waive all your rights related to the logo and that we can use it for our product

Some additional info:
The brand logo should associate security, reliability, something safe, not easy to break, strongness, power. It can also associate treasure, things of high value. It should feel strong, safe and reliable, heavy and secure. It should differentiate from other bitcoin related brand names.

Thank you for your time and effort!