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Insights The Monographic Substitution Cipher: From Julius Caesar to the KGB - Comments

  1. Mar 13, 2016 #1

    bapowell

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    Last edited: Apr 2, 2016
  2. jcsd
  3. Mar 13, 2016 #2
    Superb Insight!
     
  4. Mar 14, 2016 #3

    anorlunda

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    Well done, I learned a lot. Thank you for the education.

    It might be worthwhile to mention that good encryption practice would be to keep the message as short as possible to make statistical analysis more difficult. In the extreme, shortened plaintext morphs into code and encryption becomes unnecessary.
     
  5. Mar 18, 2016 #4
    On the other hand, if an attacker can control parts of the plaintext, compression can leak information as explained here: http://security.stackexchange.com/a/19914
     
  6. Mar 18, 2016 #5

    anorlunda

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    I didn't have compression in mind. Nevertheless, the tactic you mention is clever. I'm reminded of the old "Spy Versus Spy" cartoons from Mad Magazine.:wink:
     
  7. Mar 19, 2016 #6
    But your scheme is a form of compression, since the encoded text gets shorter.

    Anyway, just wanted to point out that getting encryption right is hard, so many things one have to consider.

    And yes, the various side channels and so on they manage to exploit is impressive and does indeed feel like Spy vs Spy :)
     
  8. Mar 19, 2016 #7

    anorlunda

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    I just remembered the canonical example of that, Heil Hitler.
     
  9. Mar 19, 2016 #8

    nsaspook

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    Chosen-plain/ciphertext attacks and hardware side channels are the bacon and eggs of Cryptanalysis.
     
    Last edited: Mar 19, 2016
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