Bitcoin Forum

I'm advertising for BitcoinStore.com, because I'm quite pleased with this particular product and you can buy it from there with BTC.  I've recently become more concerned about malicious printers (http://www.informationweek.com/security/vulnerabilities/samsung-printers-have-hidden-security-ri/240142715), so I wanted to have a small, cheap printer to go with my crappy offline laptop.  In the past, I used an existing printer temporarily disconnected from the internet and connected via USB, because printers aren't supposed to be able to remember anything.  That Samsung vulnerability made me think otherwise...

So here it is: the HP Deskjet 1000/j110A (https://www.bitcoinstore.com/hp-deskjet-j110a-inkjet-printer-color-4800-x-1200-dpi-print-plain-paper-print-desktop.html).  It cost a whole 0.79 BTC including shipping.  It's small, it's light, and it works with Ubuntu 10.04 with pre-installed drivers*, and it comes with quite a bit of ink.  I suspect these printers are just old and being sold at "below value" to make room for newer products.

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HP Deskjet J110A Inkjet Printer - Color - 4800 x 1200 dpi Print - Plain Paper Print - Desktop
http://dl.dropbox.com/u/1139081/BitcoinImg/offline_printer.jpg (https://www.bitcoinstore.com/hp-deskjet-j110a-inkjet-printer-color-4800-x-1200-dpi-print-plain-paper-print-desktop.html)

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*NOTE: The default driver selected for this printer in Ubuntu is wrong.  When it asks you which driver to use, select "HP", then DesignJet 110 (NOT "Deskjet").  Do not print a test page, since it will waste a ton of your precious ink!  Test it by printing a backup!

*NOTE2: This printer does not come with a USB device cable.  BYOUSB.

Does anyone still make dot matrix printers?

They are still made for specialty purposes like printing checks and govt forms.  However remember the spent ribbon on a dot matrix printer contains a reverse image of what is printed.  Unless you intend to keep the printer and ribbon secure and destroy all spent ribbons it is a pretty easy method to exploit.

Yes, but nowadays they are considered high-end devices. The main market is secure printing of multi-carbon-copy forms. The impact printing process and ballpoint pen handwriting are difficult to forge and easy to discover forgery attempts, even using automated processing of optically scanned forms.

Edit: D&T made a good point about ribbons. I've never seen or used a dot-matrix or daisy-wheel printer with carbon-copy-paper ribbons. The ones I've used were all using woven-fabric ink ribbons that are impossible to read from unless you print only repeated patterns (which is not impossible).

Edit2: In addition to the insecurities described in the article linked by etotheipi there are another problems with multifunction devices: many of them have large amounts of memory that is made nearly-nonvolatile by a capacitor or battery backup. It could store hundreds or thousands of simple, text-only pages for later retrieval.

A cheapie printer used with the OS-provided drivers is probably the best choice.

Interesting that your BitcoinStore link doesn't work for me... not sure why.  It just brings me to their homepage.

https://www.bitcoinstore.com/hp-deskjet-j110a-inkjet-printer-color-4800-x-1200-dpi-print-plain-paper-print-desktop.html

His URL was without https and www, so it must be the server cfg

Epson makes dot matrix printers. Really, the dangers of getting an infected off the shelf printer from your favorite computer store is small. Especially if you never intend to connect it to any other computer.

It is really a shame to buy a brand new printer, and be forced to destroy it after printing a few pages.

A brand new ribbon on Epson dot matrix printers (typical LX-300 II) is about $3 ? You can destroy that after printing 3000 pages (or when the ink starts to fade.)

Just keep your printer physically secure. Or if you are that paranoid, don't use a printer. Hand write your paper back up.

This won't be much of an issue.  I started reworking the paper backup page, and added PrinterSafe™ which encrypts the backup that is printed, and then has you write down the 64-bit encryption key ON the paper backup.  This encryption key is generated with the same keystretching as the wallet encryption, which means that, even though 64-bits doesn't seem like a lot, it will take the attacker like 0.25 sec and 8MB per guess. 

This should be sufficient for keeping your printer in the dark.

I woudln't mind a slightly better name... PrinterMask, PrinterSafe... PrintSafe?

I think the word "safe" in your "PrinterSafe" might be misleading. It is not safe if they don't have or lose the key. Using the word "Encrypted" somewhere might make more sense.

PrintEncrypt
EncryptedPrint

Maybe

SafeEncrypt
SafePrint

The "Perfect offline printer" for Armory is the Bullzip PDF Printer. :D :D

https://bitcointalk.org/index.php?topic=194570.msg2052281#msg2052281

It is indeed easier to copy. Any PDF printer will do actually. A screen capture works almost as well, but then it's a picture. I believe the point of the printed backup is so that you can place it somewhere physically safe, and without needing a computer, you can read it, or type it back in.

I have the HP Deskjet J110A that I got from bitcoinstore.com.  However, I cannot get it to print.  I got minimal love from the ubuntu forums because 10.04 is no longer supported.  https://answers.launchpad.net/ubuntu/+source/hplip/+question/236577  I got very excited yesterday when I read Alan's post regarding using the DesignJet 110 drivers.  Unfortunately I'm not finding any DesignJet 110 drivers listed.  Can anyone offer any thoughts?  I've already written out my backups by hand by both myself and my wife and verified that they are correct, but I'd rather not rely on either of our handwriting.  Thanks. 

[tinfoilhat]
Even though this is an offline printer, just don't be forgetting which central banking and oil cartel dynasty is a significant Hewlett Packard investor. Never. Ever. Put it online. If it breaks, break the EEPROM and/or flash chips, with a hammer. Then out to the landfill. Safe than sorry and all that.
[/tinfoilhat]

No doubt other printer manufacturers have less than wholesome investors about whom there is less readily available FUD and tinfoil coated spicy stories. I wonder when we'll be able to 3D print 2D printers.... I wonder when we'll be able to 3D print sheets of paper comprising individually coloured dots of pulp that rival the resolution and colour range of a 2D printer printed by 3D printer....  

Wouldn't it just be better to buy a cheapo printer from ebay, used, and literally never connect it to the net?

Also, never resell that used printer, or find a way to securely erase its memory.

"SecurePrint" is part of the new release.  It should ease some nerves about this.

@Hukfinne: I used that exact printer with my offline 10.04-32bit system about 6 months ago.  It is definitely there in the default installation (and I just checked again in my 10.04 VM).  Are you sure you were looking at the HP drivers and not some sublist (i.e. it's just "DesignJet 110", not "Color DesignJet 110")? 

etotheipi,

  Thanks, but no joy.  I just double checked, and it's not there.  This makes sense since my error message is "Unable to locate models.dat file".  On the HPLIP site it lists a models.dat file name of "deskjet_1000_j110_series", but I'm unclear where to find the file online and where to put it on my offline computer. 

  I'm running 32bit ubuntu 10.04 on an Aspire One.  Ubuntu gives me one option of using a ppd file. 

It's your lucky day!   I figured out how to export it from my clean 10.04 system.  It should be OS-agnostic, so I don't think it matters what system ultimately uses it.

I just put uploaded it to our new S3 storage space, and linked it for you right here!

HP DesignJet 110 PPD file (CDNJ500) (https://s3.amazonaws.com/bitcoinarmory-media/HP-DesignJet_110-cdnj500.ppd)

 :D Weird coincidence. Bought a printer a few months ago to replace a failed one. Guess which one...

etotheipi,

  Not only are you so awesome as to have made Armory, but your providing the ppd file enabled my printer to work. 

Within the "Add Printer" dialog, there should be the option to select the driver yourself.  Go to "System"->"Administration"->"Printing".  Then "+Add Printer".  It will "search for drivers", but even when you're online it will usually ask you to specify the make and model.  In your case, click on "HP" then continue.  Then under "Choose Driver", there are quite a few "Deskjet" options, though not 1050 specifically, but the 1000 may work.

Alternatively, you can try to find a .ppd file.  The .ppd is all you need, and instead of "selecting a driver", you just load the .ppd. 

I hope that helps.

Yes that's what I originally did and it did not find it. I tried Design Jet 1050.. that didn't work and then I just tried what you suggested (Deskjet 1000) and it still doesn't work.

How would I find a .ppd file?

It looks like HPLIP is the way to go for your printer.  I didn't see a lot of success stories when googling it.  Apparently the reason HPLIP works is because it ships all the PPD files.  Perhaps you only need to install it on another system and then find the PPD in the installed directory, then copy it over.

Also 12.04 might be better.

Thanks for the help. I will try the hplip and report back with results.

I downloaded the hplip and installed it on my Ubuntu 10.04. I selected the correct .ppd but it still gave me a CUPS error. I kept playing around with the default "select driver list" and finally got one to work with my printer "HP Deskjet 1050". The driver that worked for me was "HP Deskjet 995".

I wonder if these issue has been discussed: On many operating systems, not only network printers but local printers also have printer spools witch cache print jobs. Are those spools purged in regular and predictable manner? Can somebody malicious who gained access to the machine recover printed paper wallet from such a spool?

I've tried to find an answer to this but haven't found any definite one.

Just wondering, is there any user history of someone who lost their keys through printer hacking?

Well, just like "correct horse battery staple" is a burnt passphrase now, it has its own interesting implications to have two pages of people writing about which exact printer they'll use, where they buy it, and to announce to print unencrypted paperwallets with Bitcoins on them. Long time "Hero members" all over the place. Those with the highest desire to really secure those coins.
Just sayin'!
:-P

Seriously, there were more complicated attacks in the past than that "hey, let's break into their warehouse and put that bug into all of those printers!". Or intercept all shippments.
Ah, screw that, they'll simply find out who we are and use rubberhose decryptography. Meh.

Ente

edit:
I don't know how I got here. I don't even have a computer!
Beatcoin? Whatdoesthatmean?

Yeah, mine is carved in granite and buried somewhere. Any cheap printer will do as long as that printer never leaves your possession or is completely offline, as it should be.