Paper as a backup method

We, programmers, sometimes have to work with text encoding . But there is another type of coding that we perform constantly and so quickly that we do not notice this and forget about it. I'm talking about visual coding - recognizing the characters of the alphabet that you are doing right now while reading this text . For machines with optical character recognition, the characters of the alphabet are no different from any other incoming data stream, except that we are machines in this case.

But how effective is the alphabet as a way to encode data? Consider several different technologies for the visual presentation of data that can be seen on paper or on a monitor:

IBM 5081 punch card : up to 80 letters and numbers

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Maxicode : up to 93 letters and numbers

Data Matrix : up to 2,335 letters and numbers

QR Code : up to 4,296 letters and numbers

Aztec Code : up to 3,067 letters and numbers

High Capacity Color Barcode : varies in the number of colors and recording density; up to 3,500 characters per square inch

Printed text page: approximately 10,000 characters per page


Paper with its usual use is completely ineffective. Huge space is wasted. And this is where programs like PaperBack appear :

PaperBack is a free program that allows you to save valuable files on plain paper as a big bitmap. If you have a good laser printer with a resolution of 600 dpi, then you can write up to 500,000 bytes of uncompressed data on one paper sheet.

You may ask: “Why?” Why do we need to make backups on paper, when there are so many other possibilities for this? CD-R, DVD + R, memory cards, flash cards, hard drives, tape for tape drives, disks for ZIP Drive, file servers on the network, magneto-optical disks and even 8-inch double-sided floppy disks formatted for DEC PDP-11? The answer is very simple: why not need it. But on the other hand, just by looking at a CD or magnetic tape, you cannot tell if the data is counted from it. You will need to insert them into the appropriate device, if you have one, and try to read them.

But with paper everything is different. Remember punch cards? For years, they have been used as primary storage media for source code. Yes, punch cards when working with programs with a length of 100 thousand lines of code were, frankly, not very convenient. But, hell, because only real programmers dared to write such huge programs in those years! And used punch cards could be used as paper for notes. Widespread also received tape. Moreover, even the strangest character encodings on punch cards, such as CDC or EBCDIC , could well be read by a person (I mean real programmers).

Of course, the bitmaps that PaperBack generates are also human-readable (using any decent microscope). Just kidding You still need a scanner.

Like many of the other visual coding technologies listed above, PaperBack provides:

• Compression - to increase the amount of recorded data;
• Redundancy - in case when part of the image is damaged or unreadable for some other reason;
• Encoding - in order to protect the image from unauthorized reading.

All this technology may seem rather strange. After all, the only thing that we, poor unhappy human recognizing machines, can more or less freely recognize is just the alphabet. And when we take a sheet of paper and begin to write on it with a digital “alphabet”, then it becomes much more difficult to read than ordinary ASCII text.

But there is at least one reasonable way to use all of this. A certified paper key . And for this, there is even a special program, PaperKey :

Paper has no purpose to safely store data. For this there is an infinite number of other ways. And data backup to paper also cannot be a substitute for regular backup (to CD-R, DVD-R, tape, etc.). But then it can be used to store secret keys in case all-other-ways-haven't worked. Most of the modern media does not guarantee the storage of data is really long (years and decades). When a CD-R drive and / or tape drive and / or USB key and / or hard disk with a secret key are unreadable, paper can be used to recover the secret key.

For paper, preservation for 100 years is not something special. Quality paper and good ink can be stored for hundreds of years, even in not the best conditions.

Another advantage of paper is that a person can read it. Not all backup methods can be read after 50 years, so even if you have a backup, buying a device to read it can be a daunting task. I doubt that this will happen in the near future with a CD-R, too many of them have been released, but the backup industry is full of technologies that are now dead.

Computer data formats and storage methods come and go. That is why so many archival materials survive only in the simplest forms of existence, such as plain ASCII text. So, depending on your goals, a combination of simple digital coding and good old-fashioned, reliable, and very much time-tested plain paper may still make sense.