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Author Topic: [ANN] bitaddress.org Safe JavaScript Bitcoin address/private key  (Read 110026 times)
casascius
Mike Caldwell
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December 09, 2012, 04:55:12 PM
 #341

I would also like the qr code be left at the original size, for easier scanning. Along with printing the back of the bill with the provided pattern I
Request rejected! ;-)
The reason for plotting SMALLER QR codes in the first place was to be able to cover the QR code with above sized hologram that can be purchased easily. With the original sized QR code that is not possible, because even larger square holograms are not readily available on the market  - the largest standard sizes are 1 inch and 1.125 inch, to what I know (and if they were available, even larger ones would not look nice).

About the ease of scanning: The 15 mm size is well enough for scanning. I tried it out myself: I printed out QR codes of smaller sizes as well (and I have a rather old and cheap laser printer Brother MFC-7820N), and my cheap smartphone "Samsung Galaxy Ace" could scan it very well down to a size of 11 mm, so there is a 36% margin in size for the 15 mm chosen! Also the error protection was good: When I drew a few lines across the 15 mm QR code, the smartphone was still able to detect the right code, so I am convinced that 15 mm is a good choice. And if it still does not work to scan it, you have still the plain-text private key in the sealed pocket as fall-back, so ...

...again - everything is thought out very well! :-)

I thought I saw a checkbox that re-enabled the original size when I played with it and this wasn't even an issue?  By the way, thanks for this fantastic contribution to the community!  This alone takes paper notes a huge leap ahead.

Just thought I'd provide some input: that 36% margin in size is dependent on a lot of things that are not guaranteed.  The smaller the code, the more damage if something happens to it.  Laser toner is notorious for flaking off certain kinds of paper when creased or for no reason at all.  Someone else's printer may have poorer print quality than yours, or may have an ink cartridge that leaves black or white streaks, or may be using a print technology (e.g. dye sublimation) that makes beautiful photographs but has a hard time with black-to-white edge transitions.

On the other hand you might have a perfectly readable QR code but a user can't read it because his mediocre smartphone can't focus on the code as close as it needs to be for the smaller dots to be made out.  Quite simply, there are advantages to letting the QR code occupy the available space rather than leaving white space the user doesn't want on the assumption that there's no advantage to do it any other way.

Companies claiming they got hacked and lost your coins sounds like fraud so perfect it could be called fashionable.  I never believe them.  If I ever experience the misfortune of a real intrusion, I declare I have been honest about the way I have managed the keys in Casascius Coins.  I maintain no ability to recover or reproduce the keys, not even under limitless duress or total intrusion.  Remember that trusting strangers with your coins without any recourse is, as a matter of principle, not a best practice.  Don't keep coins online. Use paper wallets instead.
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December 09, 2012, 09:16:50 PM
 #342

I second what Mike is saying. A full size qr code, covered with a full size plaintext square of the privkey would be excellent. Everything would be taped on both sides with clear tape that is the width of the bill, and a black paper square sandwiched in between. The fully-taped in bill would be more durable than the plain paper/hologram combo, and with pattern printing on the back it should be safe enough for the small amounts of bitcoins likely to reside on them. I for one am not going to go the hologram route. Oh, also, it would be nice to have a cutting guide a couple of mm larger than the pattern itself to make it easier to cut the bill open with scissors and reveal the qr code/privkey when the time comes to redeem it.

All that's required is to mod the file to not print the privkey in plaintext on the bill with the big qr, and have it print a same-size plaintext privkey box on the side. I've no idea how hard it would be to do this though.

Michael, it would be great to see this. If it's not too much trouble, could you come up with a secondary version of your mod to fulfill these requirements? Pretty please? Smiley


Thanks!

PS: I want to hand out a bunch of these for Christmas Smiley

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December 09, 2012, 10:41:25 PM
 #343

Here is a totally legitimate reason why one might want to print bills out of known private keys.

I frequently give out 0.1 BTC with restaurant tips and to strangers.  But I know that much of the time they will probably just throw them away.  It would be nice to only give up 0.1 BTC to those strangers who really end up wanting it.  It makes it more affordable to give bitcoins to everyone, and gives them a reason to find out what bitcoins are right now, before the voucher expires.

In such a scenario, it's reasonable to put an expiration date on the voucher.  The terms of expiration are that the voucher expires if they don't redeem it, but if they do anything with it (such as send it to their own wallet), then the bitcoins never expire.  Then after the expiration date, you just swipe all the unclaimed bitcoins back into your wallet.

Being able to paste a list of pre-generated private keys makes that really easy, because eventually you'll need that same list to import into the wallet of your choice.

Companies claiming they got hacked and lost your coins sounds like fraud so perfect it could be called fashionable.  I never believe them.  If I ever experience the misfortune of a real intrusion, I declare I have been honest about the way I have managed the keys in Casascius Coins.  I maintain no ability to recover or reproduce the keys, not even under limitless duress or total intrusion.  Remember that trusting strangers with your coins without any recourse is, as a matter of principle, not a best practice.  Don't keep coins online. Use paper wallets instead.
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December 09, 2012, 11:26:19 PM
 #344

That's a great idea Mike! I've been thinking about just giving people bitcoins but I've been held back by the thought that I'm wasting my money. This way, if the bill doesn't get spent by dec 31st 2013, I'll sweep all that's left back to my wallet print new ones and hand them out again. Great, great tip! Bitcoin Faucet offline, IRL Smiley

Michael, another feature request if I may: could you set the spacing between the 3 bills on the page a little bit wider? just 5 milimetres more, it's going to make it far easier to tape, thanks. I can't wait to get started.

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December 10, 2012, 03:32:25 AM
 #345

I've been thinking about just giving people bitcoins but I've been held back by the thought that I'm wasting my money. This way, if the bill doesn't get spent by dec 31st 2013, I'll sweep all that's left back to my wallet print new ones and hand them out again. Great, great tip! Bitcoin Faucet offline, IRL Smiley

If you don't value that 0.1 BTC and are willing to give it away, then why should the person who receives it believe this piece of paper from a complete stranger would be something of any value either?

I recently experimented with a couple different approaches for this.

One that I tried just once failed but I plan to try it again with better results.  What I wanted to do was to let the person "do work" to earn the funds.   About the only "work" I could think of was bitZino blackjack or roulette.  After the person plays a few rounds, they get the payout (I'll withdraw it to their paper bitcoin).  

My first attempt at this failed because I didn't have good enough internet connectivity when trying to demonstrate it.   (My next try I might use http://KingCo.in instead for the form of "work" with someone at random as there is no need for that person to know how to play blackjack and KingCoin's game is more visually entertaining.)

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December 10, 2012, 03:46:44 AM
 #346

I've been thinking about just giving people bitcoins but I've been held back by the thought that I'm wasting my money. This way, if the bill doesn't get spent by dec 31st 2013, I'll sweep all that's left back to my wallet print new ones and hand them out again. Great, great tip! Bitcoin Faucet offline, IRL Smiley

If you don't value that 0.1 BTC and are willing to give it away, then why should the person who receives it believe this piece of paper from a complete stranger would be something of any value either?

I recently experimented with a couple different approaches for this.

Maybe they will say WTF is this and Google it.  Or maybe they won't.  I figure if they don't, in the end, all I'm out is 1/3 of a piece of paper.  They also might shove it somewhere, and 3 months later hear about bitcoin from somebody else, and realize "Oh wait I have some of that".

Just because I give something away doesn't mean I don't value it, it just means I'm willing to share.  If I tip with bitcoin, it's usually on top of a normal fiat tip.  I already tip well for good service anyway (20-25%), here in Utah that's relatively exceptional (seems any time I go out with anybody, everyone's got it wired in their brain how to calculate 15% to the penny), so I have little reason to believe that people would assume me giving it away meant it must be worthless.

Companies claiming they got hacked and lost your coins sounds like fraud so perfect it could be called fashionable.  I never believe them.  If I ever experience the misfortune of a real intrusion, I declare I have been honest about the way I have managed the keys in Casascius Coins.  I maintain no ability to recover or reproduce the keys, not even under limitless duress or total intrusion.  Remember that trusting strangers with your coins without any recourse is, as a matter of principle, not a best practice.  Don't keep coins online. Use paper wallets instead.
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December 10, 2012, 08:50:12 AM
 #347

That's a great idea Mike! I've been thinking about just giving people bitcoins but I've been held back by the thought that I'm wasting my money. This way, if the bill doesn't get spent by dec 31st 2013, I'll sweep all that's left back to my wallet print new ones and hand them out again. Great, great tip! Bitcoin Faucet offline, IRL Smiley
That was exactly the idea of my sample screenshot that I had posted here (look what is printed in the center of the bitcoin note Smiley  )  --> https://bitcointalk.org/index.php?topic=43496.msg1383041#msg1383041

Michael, another feature request if I may: could you set the spacing between the 3 bills on the page a little bit wider? just 5 milimetres more, it's going to make it far easier to tape, thanks. I can't wait to get started.
I did fulfill your other request with the larger QR code - now everybody has the choice. I also and introduced colors for the denominations and optional "glowing" effect behind these denominations. I also overhauled the GUI again quite a bit. For example, Now there are "?" buttons everywhere with lots of explanations.

Unfortunately, for this unfortunate and unnecessary narrow spacing between the bills I did not find the corresponding setting in the source code. Maybe I am just too tired... Note that I am an absolute beginner in JavaScript, I learned everything while doing it - in the end any programming language is built on logic, so it is possible... takes  time though...

I will post the update in a few minutes...

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December 10, 2012, 09:02:40 AM
 #348

Here is a totally legitimate reason why one might want to print bills out of known private keys.

I frequently give out 0.1 BTC with restaurant tips and to strangers.
Great idea to give out tips! I had the idea with expiring bitcoin vouchers already, see my post #318, but I did not quite know were I as a private person could apply it. But tipping (also) with bitcoins (in the form of expiring vouchers of course) in restaurants etc. is an excellent idea!

By the way, yesterday I met with two friends in a pub. For one of them, I handed over the casascius coins to him that I ordered for him together with my own order (and which he was very happy about of course). And then, I also put this bitcoin-demo-note on the table, and this triggered a good discussion also with friend #3 (who is not into bitcoin yet). It is fascinating that having something tangible in one's hand is just a different thing than just having the bitcoins electronically. It gives another level of inspiration and triggers much more vivid discussions, because, while you are discussing, you can take the coin or the bill in the hand, turn it around, feel it, see it, it is simply inspiring. I guess this lies in human nature.

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December 10, 2012, 09:39:15 AM
 #349

Next update - 3rd version - and probably my last one!




Only change of the content of the zip file is the HTML file - other files like documentation have not been updated (not necessary).

Changes:
* Fixed the alignment to right-align for the number at the top-right.
* Added the option of printing a larger priv key QR code that can also be sealed
   (but not with hologram then, since such large holograms don't exist)
* Added support (tooltips onMouseOver for the thumbnails to find the right RGB color codes if you do not want to print BLACK denominations. Colored numbers matching the color scheme of the note's design look just so much better.
* Added optional "glowing" feature, also matched to the color scheme (see screen shot above, the orange "glowing" behind the numbers).
* Overhauled the GUI
* Help buttons with detailed explanations are now everywhere around.
* Tool tips on mouse over of the thumbnails...
* Again more "intelligent" behavior when the private key and address do not match or are
  invalid - both in terms of dialogs and actual behaviour.

@ all: I think that's all from my side now. I cannot spend that much time for the future. I am sure it is very useful for the community.

@ pointbiz/bitaddress.org: I think you can assume that I will not do any major changes any more, and no changes at all after christmas and next year at least for quite a while. So if you intend to work on merging it into the mainstream, you can be assured that I will not "interfere" next year with yet another update... ;-)


PS: And here is the link to the latest 3rd version (9.8 MB): http://dl.dropbox.com/u/18219492/Bitcoin/bitaddress-org_Michael_S_enh_v3-zip.zip

UPDATE 30 Nov 2013: Get Version 10 (GPG signed zip file) of my tool with mBTC denomination support and some cleanups! (11.8 MByte)

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December 10, 2012, 03:35:52 PM
 #350

That's quite good! Here's  what my notes might look like:




Thanks again!
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December 10, 2012, 05:03:07 PM
 #351

Nice.

Note: For the top-right denomination, you may try out:

<font size=6>0.25</font><font size=1>__</font>

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December 10, 2012, 05:09:24 PM
 #352

You could set the default user-definable text to just, "This voucher will expire on December 31, 2099".

This will look a lot cleaner.  The far-in-the-future date says to the user, "you can replace this text by typing something else here" implicitly, instead of explaining it to them in more words than needed.  And if they print that date, then no harm no foul!

Companies claiming they got hacked and lost your coins sounds like fraud so perfect it could be called fashionable.  I never believe them.  If I ever experience the misfortune of a real intrusion, I declare I have been honest about the way I have managed the keys in Casascius Coins.  I maintain no ability to recover or reproduce the keys, not even under limitless duress or total intrusion.  Remember that trusting strangers with your coins without any recourse is, as a matter of principle, not a best practice.  Don't keep coins online. Use paper wallets instead.
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December 11, 2012, 08:58:22 AM
 #353

I could not resist. here is yet another update, version 4. I think all the user requests of the previous posts are taken into account, and more than that (that you did not think of yet, maybe)!

It has lots of new useful feature, and I also fixed artifacts of some of the rear-side designs and also slightly improved the text content at that occasion. All in the new zip container, as usual:
http://dl.dropbox.com/u/18219492/Bitcoin/bitaddress-org_Michael_S_enh_v4-zip.zip

UPDATE 30 Nov 2013: Get Version 10 (GPG signed zip file) of my tool with mBTC denomination support and some cleanups! (11.8 MByte)

First the screenshot, then what is new...:



Don't worry about the yellow and red traces, this is just the result of the (optional!) overlaid watermark demo file, one new feature in version 4! You can define any file to function as a watermark file, thereby personalizing your own prints (don't publish your watermark file digitally of course!). This should make counterfeiting more difficult, as opposed to the situation if everybody uses exactly the same design.

More new feature (hope I don't forget any):
  • BTC address QR code can now optionally defined to show not only the address, but the complete blockexplorer.com or blockchain.info URL of that address. This makes it MUCH easier for newbies, and also much faster for experts, to look up the balance of the bitcoin note with a smartphone, because upon scanning a URL, the browser will automatically pop up and you see the balance instantly without doing anything!
  • The colors of the face values (denominations) at the bottom left and top-right are now automatically changed if you select a different design. This is very nice! The colors match the color scheme of the respective design and are therefore well suited. You can still set your own color of course and can also deactivate that feature if you want. (also remember the "glow" feature from version 3. Personally, I prefer having it activated at the top-right and deactivated at the bottom-left, like in the screenshot above.)
  • Text templates are prepared for a number of different purposes that the bitcoin note can be used for. Just see yourself. I invented some fully fictional names to illustrate the use, like Ronny Paulus, Henry Fiat, Abrahamovic L., Jonny B. Cashedy or the Jekyll & Isle Ltd. Company  Wink Feel inspired to print bitcoin notes for your own purposes.
  • Finally I found out where in the source code to change the vertical gap between the 3 prints per page (I just had to replace one "height: auto;" by "height: 290px;")! Now it should be easier to cut them out, they are not that close any more!
  • Rear-side designs overhauled and improved - improved content and artifacts removed (too narrow line spacing cut off the lower parts of letters like y, g, etc.)
  • In the GUI, the "Activate Advanced Design Features" checkbox did not always do what the user supposed it to do in version 3. Now I re-organised the GUI without changing the function of that checkbox, such that now everything is logical and reasonable.

I thing now I am really done - this was my last one!

PS: I think the whole tool is intuitive, and in most cases the "?" buttons are not really needed by the average user. However, should one user lack some information or wants some deeper insight, he/she will in all probability find the needed (deeper) information behind the respective "?"-Help-Button.

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December 12, 2012, 05:25:58 AM
 #354

I still could not resist. here is yet another update, version 5 6 6b --> NOW 10.

UPDATE: Version 6 with small improvement in inter-browser-interoperability for the load/save feature.

UPDATE 30 Nov 2013: Get Version 10 (GPG signed zip file) of my tool with mBTC denomination support and some cleanups! (11.8 MByte)

My main concern was that there are so many settings now that one would like to save the complete set of settings in the GUI.
--> Now, you can!
Also, I added some German-language stuff (text templates and reverse-side-"INFO"-design).

Changes in Version 5:

HTML File:
* Added a feature to save and load all the settings on the "Paper Wallet" tab.
* Added German language templates for the text to be displayed on the note

Zip-container:
* some sample settings text files included that contain complete GUI settings - can be loaded
  into the GUI with the HTML file's new feature by simple copy-paste into the GUI's "settings"
  text box.
* Added reverse side German language designs of the bitcoin note for the version
  with the infos for newbies.
* Version history included

Screenshot Version 5:



I think now I am REALLY done - this was my VERY last one!

Delta-Screenshot of Version 6:


Change in Version 6:
* Final fix of a browser-interoperability problem (affects mutual exchange of setting strings
  on Linux between [old] firefox and Opera). Background:
  - On Linux, Opera saves line-breaks to \r\n, not to \n, when saving settings to the text box
    and copying to clipboard.
  - However, old firefox on Linux converts \r\n to \n\n when loading settings from the text box.
  This implies that then saving settings in an Opera instance of this tool and loading them back
  into firefox, all line breaks will get converted to TWO successive line breaks!
  This version of the tool is able to autodetect this situation 100% reliably and correct it
  automatically, without the user taking any notice of it. Behaviour will always be correct!
  Note: In version 5 of this tool there was a similar check implemented already, but it required
        some user interaction to remove the extra line breaks, and "false alarms" were sometimes
        possible.
* NOTE: The Parameter settings format has changed between versions 5 and 6!
        If you have created some setting files with version 5 and want to use them in version 6,
        edit them in a text editor as follows:
        1) At the very beginning of the string,
           replace <-VERSION5-> by <-VERSION6-><-MICHASNEXTPARA->
        2) Add one line break just after "<-VERSION6->", i.e. before the first <-MICHASNEXTPARA->

Change in Version 6b (mainly bugfixes):
* saving the GUI state of one of the selection boxes failed due to a copy-paste error in the
  source code. Fixed.
* The load/save of the GUI settings now by default keeps the "private keys"/"btc addresses"
  fields untouched. Some dialog still allows you to deviate from this new default behavior (the dialog
  only appears when applicable, so you do not get bothered by extra dialogs in the normal case).
* spelling errors and sub-optimum layouts fixed in a few of the selectable text templates.

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December 12, 2012, 08:06:39 PM
 #355

[...]
  • BTC address QR code can now optionally defined to show not only the address, but the complete blockexplorer.com or blockchain.info URL of that address. This makes it MUCH easier for newbies, and also much faster for experts, to look up the balance of the bitcoin note with a smartphone, because upon scanning a URL, the browser will automatically pop up and you see the balance instantly without doing anything!
[...]

but it makes loading more difficult. three qr codes???

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December 12, 2012, 08:16:12 PM
 #356

[...]
  • BTC address QR code can now optionally defined to show not only the address, but the complete blockexplorer.com or blockchain.info URL of that address. This makes it MUCH easier for newbies, and also much faster for experts, to look up the balance of the bitcoin note with a smartphone, because upon scanning a URL, the browser will automatically pop up and you see the balance instantly without doing anything!
[...]

but it makes loading more difficult. three qr codes???
Not three QR codes. Still two. It is an "either or"
--> See the prev. post in the screenshot, it shows such an example. No problem to scan them when printed out on paper - I tried with smartphone and tablet. The QR code pixels are even larger than in case of the priv. code in the small variant:

Relative QR code pixel sizes:
- Defaut bitaddress.org = 2.5
- BTC addres when incl. full URL of blockchain.info or blockexplorer.com: 1.75
- Priv QR code in the small variant: 1.4 (smallest size implemented)
- Still readable with Galaxy Ace smartphone: 1.1

PS: in most applications, it is not the idea to add funds to that address, but rather to take the funds from that address (like voucher). So having the "http://etc" inside the QR code is a win in user comfort when checking the balance. The drawback is that if someone wants to add funds to that address with a smartphone app like "bitcoinspinner", he/she needs to copy the address out of the URL string after scanning. But as said, that's not the idea in most cases.
And anyway - that feature is OPTIONAL. It is still possible to print the old-fashioned QR code (this is even the default).


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December 13, 2012, 11:26:34 PM
 #357

FYI: I added "version 6b", which fixes a small bug in the GUI settings saving.

Moreover it improves the load/save behavior w.r.t. the "priv keys"/"btc addresses" fields, plus spelling error corrections in text templates etc. I found this useful when using the tool myself for generating my first real bitcoin vouchers.

I added the download link (html file only this time) in my post #354 above (the post where I announce version 6).

Just replace the "v6" html file with the newer version "v6b" and you'll be ok - load/save formats and GUI layout are identical.

PS: My first btc vouchers from own production with cheap b&w laser printer:


(if you wonder why I chose the first and not the last day of a month as expiry date, have a look at the BTC address at the bottom-right of the photo Smiley)

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December 14, 2012, 04:54:47 PM
 #358

[...]
  • BTC address QR code can now optionally defined to show not only the address, but the complete blockexplorer.com or blockchain.info URL of that address. This makes it MUCH easier for newbies, and also much faster for experts, to look up the balance of the bitcoin note with a smartphone, because upon scanning a URL, the browser will automatically pop up and you see the balance instantly without doing anything!
[...]

but it makes loading more difficult. three qr codes???
Not three QR codes. Still two. It is an "either or"
--> See the prev. post in the screenshot, it shows such an example. No problem to scan them when printed out on paper - I tried with smartphone and tablet. The QR code pixels are even larger than in case of the priv. code in the small variant:

Relative QR code pixel sizes:
- Defaut bitaddress.org = 2.5
- BTC addres when incl. full URL of blockchain.info or blockexplorer.com: 1.75
- Priv QR code in the small variant: 1.4 (smallest size implemented)
- Still readable with Galaxy Ace smartphone: 1.1

PS: in most applications, it is not the idea to add funds to that address, but rather to take the funds from that address (like voucher). So having the "http://etc" inside the QR code is a win in user comfort when checking the balance. The drawback is that if someone wants to add funds to that address with a smartphone app like "bitcoinspinner", he/she needs to copy the address out of the URL string after scanning. But as said, that's not the idea in most cases.
And anyway - that feature is OPTIONAL. It is still possible to print the old-fashioned QR code (this is even the default).


exactly. QR codes are readable the best when they are aligned to full pixel/dot sizes. e.g. 6 dots per module.


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December 14, 2012, 05:05:40 PM
 #359

Ultimately I believe smartphone apps expecting to scan a bitcoin address should be tolerant of seeing a bitcoin address decorated with a URL, a URI, or pretty much anything.  They should be smart enough to see it's a string with a valid Base58Check-encoded substring... and should extract the substring and process just it.  This is easy for a program to do with confidence.

The whole idea of needing 3 QR codes is something I'd suggest making an option that most people won't need but some people will.  Ironically, despite having the opinion that "most people won't use this", I'm one of the people who will want it, because I value being able to scan bitcoin addresses with my USB handheld wedge wherever I want, and in many places, I won't want a URL cluttering it up.

Companies claiming they got hacked and lost your coins sounds like fraud so perfect it could be called fashionable.  I never believe them.  If I ever experience the misfortune of a real intrusion, I declare I have been honest about the way I have managed the keys in Casascius Coins.  I maintain no ability to recover or reproduce the keys, not even under limitless duress or total intrusion.  Remember that trusting strangers with your coins without any recourse is, as a matter of principle, not a best practice.  Don't keep coins online. Use paper wallets instead.
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December 15, 2012, 05:50:36 AM
 #360

exactly. QR codes are readable the best when they are aligned to full pixel/dot sizes. e.g. 6 dots per module.

If your intent is to print a QR code, your best bet is to render it in a vector format (SVG, EPS, etc.) and let the printer scale it. The pixels will end up getting rendered as a grid of black and white squares, which can be scaled up/down to any size without losing quality.

My note generator script includes code that renders QR codes to EPS. Rendering to SVG isn't too different from that.

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