2 ms·

Of courses, a OTP would be better. But there are problems with generating them (I doubt a bingo ball would be fast enough) and then you've got a courier problem

Of courses, a OTP would be better. But there are problems with generating them (I doubt a bingo ball would be fast enough) and then you've got a courier problem (hope your courier isn't a spy), etc. With a newspaper, you just have to supply a date, which can be memorized. BTW, I've used dice rolls to generate passwords, but the dice would always fall off my desk and roll into an inaccessible corner, and I soon tired of that. It also only worked for 6 digits! So I switched to a real RNG.

mannykannot 1y ago
The point that your scheme requires just one date to select single newspaper as a key for one U-boat per patrol underscores how feasible it would be for an organization with the resources of the German navy to generate the same sized random keys, your personal experience with key generation notwithstanding. As for key interdiction, it would have to be at massive scale, as having a handful of random keys does not enable industrial-scale decryption, which is what the allies needed (and had, some of the time) for signals intelligence to be useful against U-boats. In contrast, the leaking of one date would compromise the entirety of the communications conducted under it (i.e., at least those for one U-boat for the duration of the patrol), especially given that German newspapers were readily available in neutral and occupied countries. OTPs are, in fact, way more resistant to espionage than your newspaper scheme. The failure of the location-shifting scheme (as mentioned in my previous post) to stop the allies interdicting rendezvous, despite its periodic changes, also suggests that one date per patrol is not going to be good enough. We have reached the point where the alleged superiority of your newspaper scheme hangs on the tendency of dice to roll off your desk!

2 ms·

Of courses, a OTP would be better. But there are problems with generating them (I doubt a bingo ball would be fast enough) and then you've got a courier problem

by WalterBright 1y ago

mannykannot 1y ago
The point that your scheme requires just one date to select single newspaper as a key for one U-boat per patrol underscores how feasible it would be for an organization with the resources of the German navy to generate the same sized random keys, your personal experience with key generation notwithstanding. As for key interdiction, it would have to be at massive scale, as having a handful of random keys does not enable industrial-scale decryption, which is what the allies needed (and had, some of the time) for signals intelligence to be useful against U-boats. In contrast, the leaking of one date would compromise the entirety of the communications conducted under it (i.e., at least those for one U-boat for the duration of the patrol), especially given that German newspapers were readily available in neutral and occupied countries. OTPs are, in fact, way more resistant to espionage than your newspaper scheme. The failure of the location-shifting scheme (as mentioned in my previous post) to stop the allies interdicting rendezvous, despite its periodic changes, also suggests that one date per patrol is not going to be good enough. We have reached the point where the alleged superiority of your newspaper scheme hangs on the tendency of dice to roll off your desk!