The official BitcoinPaperWallet.com thread -- updates and news.

[canton]

New design looks great!

Thanks, and again thanks for your extremely useful feedback.

For anyone who doesn't quite see how the new design addresses yellowcoin's "pull out the fold with stickytape" hack, here's how the new design folds up In Real Life



Now the two strips of tamper-evident tape stick to all 3 panels of the fold, preventing it from being snuck out.

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[Malawi]

Time to send another one to Karl Marx for testing?

[NoL1m1tZ]

IDK if it was still a question, but I would like to confirm that all of your QR codes worked for me. Secondly I think this is really cool, keep up the good work man.

[pointbiz]

I love this idea and what you've done with it. It's nice to have the private key hidden when carrying it in your wallet and being reasonably sure it hasn't been tampered with when you put your wallet on a table. They can be carried with you so not all your BTC is on your mobile phone (online). And you can use them to transfer BTC to other trusted parties who will know they should sweep the funds within a short time span.

Here is a link to a similar concept I proposed:
https://bitcointalk.org/index.php?topic=51978.0

I wonder if your method can be tweaked by just using tape instead of tamper resistant stickers. Obviously it's less secure but might be good enough for lower BTC amounts.

[canton]

I wonder if your method can be tweaked by just using tape instead of tamper resistant stickers. Obviously it's less secure but might be good enough for lower BTC amounts.

Definitely still works with regular tape, especially if you're mostly concerned about casual tampering (wallet on the table) as opposed to dedicated fooling around with liquid solvents and heat guns.

To this end:

#1: Today I soft-launched https://bitcoinpaperwallet.com which not only provides the wallet generator (in-browser two-sided printing) but also features security tips, and allows you to purchase custom holograms using bitcoin. Wallet generator is open-source and can run entirely offline as it's based on bitaddress.org.

#2: Somewhat unrelated, but I entered a variation of my design for a *non-folding* project organized on bitcointalk.org. These paper wallets will be professionally printed (any you'll only home-print the keys/QR codes.) Have a look and vote for whichever design appeals most to you: https://tricider.com/en/brainstorming/poxx

[ripbitinstant]

Very cool! Works well.

The calibration didn't align the front and back 100%, but it probably has to do with the printer rather than the design. I just had to cut the edge a little closer. All this did was uncenter the Bitcoin symbol over the private key, although it was entirely visible. I used Zoom: 3, Shift: 7 if that helps anybody else.

Any chance there will be an option to specify the size? Would that mess up the Zoom/Shift settings? I think it would be cool to have it the same size as paper currency, but I suppose paper currency has different sizes throughout the world.

Great stuff

[canton]

The calibration didn't align the front and back 100%. I used Zoom: 3, Shift: 7 if that helps anybody else.

With any combination of zoom/shift settings, did you manage to get the calibration page to print out perfectly *centered* (horizontally centered, that is?) That's the factor that influences how accurately the front/back line up. For zoom 3 / shift 7, what browser / OS were you using?

If anyone reading this thread is scratching their heads, this is what we're talking about:



So far I've had the best success with Safari, pretty good with Firefox & IE, possibly some problems with Chrome.

Any chance there will be an option to specify the size? Would that mess up the Zoom/Shift settings? I think it would be cool to have it the same size as paper currency, but I suppose paper currency has different sizes throughout the world.

Not yet. I'll think about that some, like a "master zoom" function. However the resulting wallets wouldn't size properly for the tamper-evident tape I sourced -- so you'd be obligated to use regular tape.

[pointbiz]

Another security idea is to use a printer which support on-site Printing, eg you put a Picture or PDF on a USB or SD card, and then you print with the printer "stand alone".

Many printers today have the capatibility to print files from a USB or SD card.

Since the computer cannot know which off-line stand-alone printer you use, the risk of getting a "fake firmware update" is negligible. Many printers also have a sequence that needs to be triggered Before it will accept a firmware upload via USB/SD, so its completely secure. For example Power on the printer with the firmware update USB/SD inserted. So never turn on the printer with a SD or USB inserted to be on the safe side.


For a leak to sucessfully travel from your printer to internet, the printer would have to "infect" the usb with a autorun software containing the private key AND a "payload" that transmits the private key home. And for such infection to exist in the printer, it would have to travel from computer to printer via USB/SD, and for that to happen, the printer must be able to receive software updates arbitary via USB and the computer needs to know the exact model of your printer.

+1

Brilliant!

Offline computer using Chrome printing to PDF... PDF saved to SD card... SD card inserted in printer.

[pointbiz]

#1: Today I soft-launched https://bitcoinpaperwallet.com which not only provides the wallet generator (in-browser two-sided printing) but also features security tips, and allows you to purchase custom holograms using bitcoin. Wallet generator is open-source and can run entirely offline as it's based on bitaddress.org.

Looks great. Can't wait to print some.

[ripbitinstant]

The calibration didn't align the front and back 100%. I used Zoom: 3, Shift: 7 if that helps anybody else.

With any combination of zoom/shift settings, did you manage to get the calibration page to print out perfectly *centered* (horizontally centered, that is?) That's the factor that influences how accurately the front/back line up. For zoom 3 / shift 7, what browser / OS were you using?

Chrome / Windows 8.

So far I've had the best success with Safari, pretty good with Firefox & IE, possibly some problems with Chrome.

I'll see if I can try another browser soon.

Not yet. I'll think about that some, like a "master zoom" function. However the resulting wallets wouldn't size properly for the tamper-evident tape I sourced -- so you'd be obligated to use regular tape.

It was just a thought. It may not be doable. It's awesome as is Since carrying it around in your wallet sort of defeats the purpose, my thought is probably bad, but maybe a function then to print a "public" bill that has only the public key and doesn't fold... that way you can carry it around without worrying that your funds will be stolen, even if your (physical in real life) wallet is. Both (the "secret" bill and "public" bill) would be able to print on one sheet of paper.

Anyway, just spitballing. I think it's really cool already. Cheers!

[teff]

The calibration didn't align the front and back 100%. I used Zoom: 3, Shift: 7 if that helps anybody else.

With any combination of zoom/shift settings, did you manage to get the calibration page to print out perfectly *centered* (horizontally centered, that is?) That's the factor that influences how accurately the front/back line up. For zoom 3 / shift 7, what browser / OS were you using?

If anyone reading this thread is scratching their heads, this is what we're talking about:

https://i.imgur.com/fZlxoaK.png

So far I've had the best success with Safari, pretty good with Firefox & IE, possibly some problems with Chrome.

Any chance there will be an option to specify the size? Would that mess up the Zoom/Shift settings? I think it would be cool to have it the same size as paper currency, but I suppose paper currency has different sizes throughout the world.

Not yet. I'll think about that some, like a "master zoom" function. However the resulting wallets wouldn't size properly for the tamper-evident tape I sourced -- so you'd be obligated to use regular tape.

Using Chrome / Windows 8 printing on a HP CLJ, the zoom and shift didn't seem to do anything at all, but the extra bleed on the back was adequate to make it a reasonable fit, here is the bleed after been cut with the details from the calibration page behind, maybe it just needs extending on that leading edge at the right of the picture

https://i.imgur.com/MfDirzr.jpg?1

[exor674]

First of all and I say this again... GREAT JOB!!!
I love the design and your website is great too!
Now to the constructive criticism:

I made my first paper wallet using your web site. There are no concerns there, it worked flawlessly, I used Safari and I used an ink-jet printer and the design is a work of art but I printed the wallet in photo/presentation paper which it's not a problem since I figured the paper is sturdy, makes the design look better and I believe it's more durable. That being said, the paper is not designed to be folded!!! to my surprise, the paper slightly broke when I folded (see photo here https://dl.dropboxusercontent.com/u/72382452/Photo%20Apr%2023%2C%2012%2038%2031%20PM.jpg)
So my concern is the private key in the inside of the fold. Could you find a gracious way to split the private key so the folding area does not tamper with the characters? I'm concerned about the folding messing with the characters and making them unreadable.
I'm sure this issue is not only associated to photo paper but any kind of paper since the fibers are broken when you fold a piece of paper.
I know the QR code is fine, but I'd feel better having redundancy (QR & actual private key)
Anyways, my 2cts for your design.

Great work again!

I believe this is why the textual private keys aren't lined up so any damage will damage different parts of the key. See https://i.imgur.com/4Pmh5lp.jpg ( grr, had the wrong link here before I decided to remove the half letters to simulate more damage ) -- [ printed wallet, cut the flap in half, and removed any half letters ( simulating a pretty huge space of damaged textual key -- and honestly, I really doubt damages from a fold will damage exactly one letter ) ] -- QR code removed because I'm feeling silly and havehad 0.05BTC sitting on that address if anyone can recover the private key.

[ripbitinstant]

I believe this is why the textual private keys aren't lined up so any damage will damage different parts of the key. See https://i.imgur.com/4Pmh5lp.jpg ( grr, had the wrong link here before I decided to remove the half letters to simulate more damage ) -- [ printed wallet, cut the flap in half, and removed any half letters ( simulating a pretty huge space of damaged textual key -- and honestly, I really doubt damages from a fold will damage exactly one letter ) ] -- QR code removed because I'm feeling silly and have 0.05BTC sitting on that address if anyone can recover the private key.

I'm re-reading this and now I'm undecided. I first thought it was a bounty. Is it?

[exor674]

I believe this is why the textual private keys aren't lined up so any damage will damage different parts of the key. See https://i.imgur.com/4Pmh5lp.jpg ( grr, had the wrong link here before I decided to remove the half letters to simulate more damage ) -- [ printed wallet, cut the flap in half, and removed any half letters ( simulating a pretty huge space of damaged textual key -- and honestly, I really doubt damages from a fold will damage exactly one letter ) ] -- QR code removed because I'm feeling silly and have 0.05BTC sitting on that address if anyone can recover the private key.

I'm re-reading this and now I'm undecided. I first thought it was a bounty. Is it?

Well, it *was*: https://blockchain.info/address/15mNseGxoTxq3yWeR6utULoeQdWuJYSgNy

[ripbitinstant]

I believe this is why the textual private keys aren't lined up so any damage will damage different parts of the key. See https://i.imgur.com/4Pmh5lp.jpg ( grr, had the wrong link here before I decided to remove the half letters to simulate more damage ) -- [ printed wallet, cut the flap in half, and removed any half letters ( simulating a pretty huge space of damaged textual key -- and honestly, I really doubt damages from a fold will damage exactly one letter ) ] -- QR code removed because I'm feeling silly and have 0.05BTC sitting on that address if anyone can recover the private key.

I'm re-reading this and now I'm undecided. I first thought it was a bounty. Is it?

Well, it *was*: https://blockchain.info/address/15mNseGxoTxq3yWeR6utULoeQdWuJYSgNy

Okay. That was me. I just wanted to make sure I was actually allowed to steal it. But I guess I'm derailing this thread a bit. Sorry.

[P_Shep]

I'd do something like this, where the middle two QR codes are actually randomly generated nonsense data.

[Terk]

I'd do something like this, where the middle two QR codes are actually randomly generated nonsense data.

This. Great idea. I'd also add some message on the bogus codes to avoid confusion:

[P_Shep]

Also on the other side of the paper too, behind the actual private key.

[canton]

Also on the other side of the paper too, behind the actual private key.

For fun, maybe instead of QR codes, random dot stereograms Seriously though, I thought of doing bogus QR codes but I was afraid of usability issues for novices... maybe if there's a real obvious "NOT HERE" type mark. I'll think about this some more.

[bitcoinminer]

This is a really cool thread, idea, and execution.  I may have use for these in the near future

If I could make one small suggestion, put a web address somewhere on the template for basic instructions, so I can give to a newbie and they can learn everything they need to, like bitcoin.org or whatever.