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Showing 13 of 13 results by exor674
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Board Service Announcements
Re: Criticize my tamper-proof paper wallet design... and steal 0.1 BTC if you can.
by
exor674
on 09/05/2013, 19:21:45 UTC

PS: If you decide not to buy a laser printer, there are some ways you can make your inkjet-printed wallets more water-resistant. I'll be posting a report on this soon as I'm in the process of testing a bunch of different products/solutions.


I'm slightly curious how well it'd work to do a three-pass print and not a two-pass. ( which makes this even closer to the other project, but... )

Print the front and back in color without the QR codes on some printer [ color laserjet, color inkjet? I wonder how it'd work if those ink could bleed when wet when the QR code couldn't? ], and then print the QR codes on a cheaper black and white laser printer.

This would probably also work for your "super paranoid" option, without having to buy a nice color laserjet and only use it for wallets.

[ However, I imagine the pain this would be to align and calibrate across two different printers ]
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Board Service Announcements
Re: Criticize my tamper-proof paper wallet design... and steal 0.1 BTC if you can.
by
exor674
on 23/04/2013, 21:12:59 UTC
I believe this is why the textual private keys aren't lined up so any damage will damage different parts of the key. See http://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
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Board Service Announcements
Re: Criticize my tamper-proof paper wallet design... and steal 0.1 BTC if you can.
by
exor674
on 23/04/2013, 18:16:46 UTC
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 http://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.
Post
Topic
Board Project Development
Re: [BOUNTY: 10+BTC] Open Source (CC) Paper Wallet Kit for safe offline coin storage
by
exor674
on 22/04/2013, 17:44:30 UTC
Can you please submit a design that matches the agreed template and layout exactly?

Done! I don't think the margins are ideal in the template (important content unnecessarily close to the paper edge) -- and I think it's a mistake to omit the public key from the backup stub -- but I've submitted a revised design that strictly conforms to the template.

https://tricider.com/en/display/104330?wicket:pageMapName=wicket-4


It would probably be an easy fix in the design [ add a white box ], but I'm curious if inkjet printers would be content overprinting the design for the textual public key.

I'm not sure the level of permeability of printing press ink [ or what process aanthonop plans on using ]. ( While I do have access to professionally printed things I wouldn't mind ruining, I do not have access to an inkjet to test )

Post
Topic
Board Games and rounds
Re: BTCJam forum name verification
by
exor674
on 20/04/2013, 20:56:32 UTC
I want to link my Bitcointalk name with BTCJam's. Verification code: b514d254-1c20-493b-aaf6-2385b130eaeb
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Board Service Announcements
Re: Criticize my tamper-proof paper wallet design... and steal 0.1 BTC if you can.
by
exor674
on 20/04/2013, 04:00:38 UTC
I wonder what QR code generator you use, because I didn't think it was possible to get QR codes to misread

Hmm, I hope this is just a blurring/resolution issue from taking a screenshot and then shrinking the size and applying JPG. I'm using the same code and QR generator as bitaddress.org -- the only fundamental difference is the web interface, CSS/HTML and the background art.

Here's a non-downscaled sample. Would you see if the sample below reads correctly 10/10 for you? The QR codes when printed are quite sharp. Significantly sharper than this JPG.

http://i.imgur.com/03MhJNI.jpg

Couldn't get that one to read garbled even when I tried vile things with it ( rotating the camera, off-axis, etc... ) so was probably the blurriness.
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Board Service Announcements
Re: Criticize my tamper-proof paper wallet design... and steal 0.1 BTC if you can.
by
exor674
on 20/04/2013, 02:46:07 UTC
I worked on about 5 or 6 variations last night before I hit on this one which isn't significantly more difficult to cut out with scissors. In my own tests, this new shape overcomes this exploit while still using the original design that calls for two strips of 2" x .625" tamper-evident tape. (When you fold this new design up, the tape now sticks to all three "panels" in the folded area so the innermost panel can't be snuck out.)

Thanks again yellowcoin for the excellent experiment.

http://i.imgur.com/Cx4Tg8V.jpg

PS: Yes, those are live keys, but there's nothing stored in them this time. Yet. Smiley

I wonder what QR code generator you use, because I didn't think it was possible to get QR codes to misread [ either they'll scan, or it'll fail ]. Because, out of like 8 tries, I've read "1264FsZE5Fkc7TcsP1qg4PTcVi3^VYMgrA" off that QR code twice.

I do think that new design is a good compromise between cutting difficulty and the issue with sneaking the panel out, though.
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Topic
Board Service Discussion
Re: blockchain.info wallet - moved between wallet message
by
exor674
on 19/04/2013, 19:46:44 UTC
Post
Topic
Board Beginners & Help
Re: Transfer issues from bitfloor to blockchain.info
by
exor674
on 19/04/2013, 04:07:36 UTC
Looks like it all went in a bunch about 12 hours later. Or maybe it was blockchain.info that was having problems? I could not access their wallet for a day afterwards.

Yeah. Blockchain.info had some downtime last night.
Post
Topic
Board Beginners & Help
Re: My Bitcoins are gone in blockchain and i don't have any support.
by
exor674
on 19/04/2013, 04:04:24 UTC
1,021 BTC is a lot different than 1.021 BTC

Note that some regions use , instead of . for a decimal place seperator.
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Topic
Board Beginners & Help
Re: How do you trade Bitcoins for Litecoins?
by
exor674
on 19/04/2013, 03:55:44 UTC
Yes they do.
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Topic
Board Beginners & Help
Re: I'm new here...
by
exor674
on 19/04/2013, 03:50:23 UTC
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Topic
Board Beginners & Help
Re: all gone
by
exor674
on 19/04/2013, 03:43:15 UTC
What is all gone?  Huh