Talk:Ghostwriter System/@comment-5982125-20131214190722

They would obviously provide, included in the literature - the code-books and such - with the machine, a diagram of what the keys mean, so that someone who's not trained to use the machines can make a hash of it as long as they know the Ghosthand code [and if they're an officer, they have to know how, so they can read their orders]. All the literature for the machines is printed in red water-soluble ink on thin pink paper so it's very easily destroyed: all you have to do is get it wet, and it will also burn up almost instantly. The books are bound in red card stock that's treated to be very rapidly flammable so that all you have to do is get your lighter - every soldier has one, they're all issued with these fancy blued steel zippo lighters - and burn one corner of the cover and it'll all go up in flames. The books' covers are wrapped in plastic since they're so delicate (yes, Saranwrap was invented in 1933), so just rip the plastic off and set it on fire.

The biggest problem with it all is that there are SO MANY different settings on the cypher machines and all the settings except the positions of the drive wheels have to match for the machines to work. They're not random. Every modification on every letter is completely controlled so that when an encoded message is passed through a machine that's configured the same as the one that encoded it, it comes out of the machine uncoded. So there's a very complicated system of channels and settings that is used by the different operators. That way, if the encryption settings for one machine is compromised, the enemy won't know any of the others --- and every hour, they modify the settings, so unless the enemy also has a copy of the Codebooks and Orders of the Day, as soon as the hour is up, they will no longer be able to decypher messages using the settings of their captured machine even on the same channel, since they won't know how the settings will have changed. Granted, cracking that same channel again will still be easier, since they only introduce a few modifications on an hourly basis ... but even still, the settings change completely the next day and the enemy is back to square one. Assuming the enemy can gain access to an intact Ghostwriter Machine, it will help them, but there are so very many possibilities that it would take forever to make any real progress in totally cracking the code. And even then, there are just too many settings... the best they could do would be to spend several years to produce a table of what letter becomes what new letter with EVERY POSSIBLE COMBINATION OF SETTINGS. Which would lead to a gigantic table of thousands of different substitution combinations that would have to be consulted exhaustively to decrypt every single message, because they wouldn't know the configuration of the machine that sent the message. And it would be a lot easier for the Americans to simply introduce new sets of rotors with different wiring combinations or make other simple alterations to render those tables of combinations that the enemy has incorrect.

The Enigma machines were designed to be effective even when the enemy was aware of the wiring configuration of the rotors (i.e. if the primary encryption method for the Enigmas was compromised). But in reality, that wasn't really the case --- having the substitutions (i.e. what letters become converted to what other letters by the rotors when the rotors are in a given set of positions) known compromised reduced the permutations from 10^114 to 10^23. The Ghostwriter machines have so many other features that, even if the enemy knows the wiring configurations of the rotors, it will still be extremely difficult to crack. I doubt the Blechly Park people would be able to crack the Ghostwriter code even if they knew the wirings of the rotors. They might figure out some of the channels, but there are so many modifiable features that knowing 1 or 2 channels won't help all that much. Without having access to the codebooks and encryption keys, they'd be at a loss. Without knowing the rotor wirings, not even the Blechly Park people would be able to figure it out.

Basically, the reason the Enigma machines didn't work in practice is because they were just modifications of the rotor machines used by pretty much every other country at the time, and the designers of the Enigma didn't expect anyone would try such an exhaustive brute force approach as the Blechly Park operation. The Ghostwriter machines are designed to be effectively immune to being completely compromised by a brute force approach. Whether they actually are, well, that's not said --- but as far as the Americans are aware, nobody has cracked it yet.