Printing Keys and using OCR (was: Proofreadable base64)

[Brian Smith]

Peter Palfrader wrote:
> Nice idea.  When trying to find decent backup methods for my 
> new Tor identity key I cam accross this thread.
> 
> I played all day with ocr and friends.  In the course I wrote 
> a small script that does what you suggest.  I tried to keep 
> it small enough to print it along with whatever data you have 
> - I clearly failed there.
> But other than that it works nicely.
> 
> That didn't work out so well at  first
> - gocr had real trouble distinguishing zeroes and the 
> letter D like Delta. 

Why not use a 2D barcode like a QR code? A QR code will hold most
typical keys, is easy for machines to read, is small, and has redundancy
features that allow it to work even if you hole-punch or black out part
of the code.

See http://www.denso-wave.com/qrcode/aboutqr-e.html

- Brian