It really highlights the amazing security level of one time pads, that they can be comfortably doing secret announcements on a public radio channel with provably perfect security. (Assuming an adequate PRNG--for such small messages they could easily be using a hardware PRNG; I wonder.) Only issue is that you have to have all of your recipients keep track (and not leak) a pad that is at least as long as the data you intend to send.
mdhb|2 years ago
They are very cumbersome to use in real life, encrypting and decrypting is done by hand, it’s error prone as a result and very slow. Nobody likes using them at all.
The part you mentioned about the keeping track of and not leaking it also isn’t really an issue so much in reality.
What you hear on the radio isn’t actually that sensitive on its own hence why it’s happily sent in the clear without the key material to decipher it.
The pads themselves are however highly guarded secrets, usually passed along via a dead drop, only ever exposed to the minimum of people and designed to be very easy to destroy quickly and are a bit flimsy as a result.
But destroying the pad is a part of the whole “how to receive a message securely” process that they go through so it never exists to be used as evidence beyond the time that it’s actually useful.
Also the people handling them are highly trained and trusted individuals who are extremely motivated to be very sensible while working with them as the entire reason you would use a method like this in particular is usually because you will be tortured and shot if discovered.
This is ironically also why it doesn’t make sense usually for that person to have access to and know how to use a shortwave radio. If you get caught with that equipment your fate might be the same either way.
Some fun trivia: the British as far back as the 50s I believe did have some success where they had developed a system that allowed them to essentially use direction finding techniques but for radios that were tuned to a specific frequency even if they weren’t transmitting. It was known as Operation Rafter and is on Wikipedia.
One more example I’ll throw out there if you want to read a cool story is an account of how the ANC (the political group associated with Nelson Mandela) developed their own covert communications system with a lot of similar properties when they were trying to overthrow the apartheid government in South Africa during the 80s and 90s.
It’s a great read https://omalley.nelsonmandela.org/index.php/site/q/03lv03445...
MOARDONGZPLZ|2 years ago
One other note here is that OTPs don’t have to be distributed in this manner. An OTP can use something already distributed and readily available to end users, such as a Gideon Bible or something (making sure to get the right edition, printing, etc) that everyone in a hotel room has access to. The key is having access to something, making sure it’s long enough for the series of messages to be encoded/decoded, and that no one else knows what it is.
rawling|2 years ago
There's no need for that to be true.
ezconnect|2 years ago