Using Insecure lines

Hiding the message with a crypto key
Page #435 of Chapter: Crypto-for-the-rest-of-us

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If you can't hide the fact that you send a secret message, and you have no secure channel available, then resort to insecure channel, and protect your message by reshaping it so that only a key holder can extract its meaning.

Ideally you may want to:

  • Hide the method used to reshape the message (process the plaintext to its ciphertext) -- obscurity

  • Use a method that does not allow the key to be deduced from the ciphertext (equivocation)

  • Otherwise: use a method that would require too much time and effort to deduce the key from the ciphetext (eroding intractability)
  • * Version CE-H6703 (SERVER) Crypto Academy