11–20 of 144 posts
And (more or less) that’s how the Enigma was cracked. Turns out starting weather report with ‘weather’ every single time is not a good idea.
Interesting. I liked the explanations in the accepted answer. This rule especially,“Never repeat in the clear the identical text of a message once sent in cryptographic form, or repeat in cryptographic form the text of a message once sent in the clear.” As a child I learned about codes from a library book. Fascinated with one-time pads, I convinced a friend to try a correspondence. We exchanged a few messages, and th…
I recall that Ovaltine goes better with decoded messages.
Does this also apply if someone were to do the following: Receive encrypted transmission -> unencrypt it -> need to pass it on, so re-encrypt it and pass it on? I would imagine that the paraphrasing wouldn't be necessary in this case because it isn't quite as useful to compare two encrypted versions of the text versus an encrypted version and an unencrypted version (also I feel like there is some risk of a game of 't…
> Never repeat in the clear the identical text of a message once sent in cryptographic form, or repeat in cryptographic form the text of a message once sent in the clear And (more or less) that’s how the Enigma was cracked. Turns out starting weather report with ‘weather’ every single time is not a good idea.
Interesting. I liked the explanations in the accepted answer. This rule especially,“Never repeat in the clear the identical text of a message once sent in cryptographic form, or repeat in cryptographic form the text of a message once sent in the clear.” As a child I learned about codes from a library book. Fascinated with one-time pads, I convinced a friend to try a correspondence. We exchanged a few messages, and th…
>> the juice wasn’t worth the squeeze I recall that Ovaltine goes better with decoded messages.
Tangentially related — sending everyone in a company a slightly different document can help catch the person leaking confidential documents to the press.
Tangentially related — sending everyone in a company a slightly different document can help catch the person leaking confidential documents to the press.
Does this also apply if someone were to do the following: Receive encrypted transmission -> unencrypt it -> need to pass it on, so re-encrypt it and pass it on? I would imagine that the paraphrasing wouldn't be necessary in this case because it isn't quite as useful to compare two encrypted versions of the text versus an encrypted version and an unencrypted version (also I feel like there is some risk of a game of 't…
No. As explained in the SO answer, the worry is that the enemy will have been able to decrypt one or the other of your messages, at which point the identical underlying plaintext will help them crack the second cypher.
If they have already gained the ability to decrypt today’s messages from station A in cipher A, and can therefore recover the plaintext of those messages; if they then find a message of the same length sent from station B in cipher B they can guess that that might be the same message, reverse engineer the key and maybe then decrypt all the messages being sent from station B in cipher B today.
> Never repeat in the clear the identical text of a message once sent in cryptographic form, or repeat in cryptographic form the text of a message once sent in the clear And (more or less) that’s how the Enigma was cracked. Turns out starting weather report with ‘weather’ every single time is not a good idea.
Or ending it with the same salute involving the name of the leader, for that matter.