How retro can you get?

It seems that secrets are not necessarily... well, secret any more.  Computers can be hacked, hard drives can be copied, files can be decrypted.  So the Russian secret service have come up with an innovative idea - they are reverting to typewriters! They can't be hacked because they don't store data and as every typewriter produces an individual pattern of type, any document can be traced back to the machine that created it.  The old ideas are sometimes the best you see.