Hey everyone, I just wanted to post an update about the status of
Piper, the paper wallet generator and printer. We've changed the design of the paper wallets to a new one created by Jason Sawtelle. A picture is below:
We've also added some new features. Piper now has 2 modes: Remember mode and Forget mode. When Piper is in remember mode, all private/public keypairs will be stored on Piper's internal memory. If you plug in a USB flash drive, Piper will automatically copy the stored keys to the flash drive. When Piper is in forget mode, the keypairs will not be stored and the keys will exist only on the actual paper themselves. The mode can be selected with a switch on the top of the unit. This video shows a demo of that functionality, and also the new wallet design as well:
http://youtu.be/v5jmFJN1_csWe upgraded our paper to one with a 7 year image life (assuming the paper is stored in cool, dry office filing type conditions). We're also working on a new foldable design tailored for use with tamper-proof holographic stickers, as an option. You can always use your own printer with Piper's USB port, if you like.
Finally, we are proud to announce that Piper has passed the 26 tests of randomness from the Dieharder suite (
http://www.phy.duke.edu/~rgb/General/dieharder.php) We tested /dev/urandom with every test rated "good" or higher in the Dieharder suite and Piper passed them all (except for the RGB Generalized Minimum Distance Test which is clearly broken since it reports a p-value of 0.00000 and fails on every other system we could get our hands on as well). Since Piper uses vanitygen to generate it's keypairs, and vanitygen uses /dev/urandom for it's random seed, we can say that the keys generated by Piper are safe. Piper actually has a hardware random number generator built into the SoC that it uses to ensure that it has sufficient entropy to generate cryptographic keys. Piper comes with the shell script used to run the Dieharder tests, so you can test your own unit if you like. Here's the results of a run of all 26 tests:
http://piperwallet.com/dieharder-results.txtThe enclosure design was sent to the manufacturer today and I should be receiving a prototype enclosure towards the end of the week, so I'll post pics when it comes in the mail.
Thanks for your support, everyone! More info can be found in the FAQs here:
http://www.piperwallet.com