Secret diplomatic message deciphered after 350 years
(nationalarchives.gov.uk)60 points by robin_reala 2 days ago
60 points by robin_reala 2 days ago
If quantum computing would progress just like in the last 30 years it may take 300 years before it can be useful.
It was quite common to have a codebook that might list several numbers or words used to substitute for places, individuals, actions, etc.
These also existed for corporate entities. A concern might have their own codebook such that the telegraph office would not be privy to their internal business.
They would also use codebooks as a type of compression, since the telegraph company charged less for sending English words as opposed to enciphered characters, and obviously, there are many uncommon words that could substitute for longer common phrases.
https://en.wikipedia.org/wiki/Codebook
https://en.wikipedia.org/wiki/Commercial_code_(communication...
I sat through a briefing last week about quantum encryption and the threat that quantum computing poses to encryption in use today. It was stressed that nation states are hoovering up encrypted data now in order to decrypt later with quantum computing. Much the same way America decrypted old soviet encrypted data. I wonder if it will take as long and if anyone will still be alive to make use of that data.