Timeline for Using one-way hash functions as the encryption method
Current License: CC BY-SA 3.0
7 events
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| Sep 3, 2013 at 17:55 | history | edited | D.W. | CC BY-SA 3.0 |
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| Sep 3, 2013 at 17:26 | comment | added | Richie Frame | "the" would be an example of a crib. It allows you to derive the meaning of part of the plaintext. Weather reports almost always started with the same thing, and that allowed derival of the key knowing the scheme. In this scheme, cribs are way more effective, since Enigma encrypted words differently within the message. | |
| Sep 3, 2013 at 15:35 | comment | added | Ilmari Karonen | @jj57: Having an Enigma machine just tells you how the scheme works, not what key was used to encrypt a given message. A modern, secure encryption scheme would not have been affected in any way by an attacker obtaining an encryption device, or even a detailed schematic of one. See Kerckhoffs' principle for details. | |
| Sep 3, 2013 at 10:41 | comment | added | jj57 | They cracked the Enigma code because they got a hold of an Enigma machine. Also their randomness produced by operators was insufficient, there were procedural flaws, operator mistakes, laziness, neglect of the need to introduce systematic changes of encoding parameters, crib-dragging and capturing of key tables and hardware. That's how Allied cryptanalysts were able to be so successful. | |
| Sep 3, 2013 at 9:31 | comment | added | Richie Frame | "If an attacker decrypted the word the it is not that useful to understanding the remaining content or intent of message." Actually, that is how the allies cracked the German Enigma code during WW2. That and knowing the scheme, which they partially reverse engineered. | |
| Sep 3, 2013 at 8:19 | comment | added | jj57 |
Sure the word the might be encrypted the same way, but I specifically mentioned it should be avoided using common words like that in messages. Even if this is a big clue to cryptanalysts as you say, how does it help them decipher the message? If an attacker decrypted the word the it is not that useful to understanding the remaining content or intent of message. All other words may have more or less the same chance of occurring. This doesn't help an attacker given they know nothing about the length of each word either seeing all encrypted words are the same length.
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| Sep 3, 2013 at 7:29 | history | answered | D.W. | CC BY-SA 3.0 |