One-time-pad - The Diigo Meta page

• 12 Feb 14
  

  greenup greenup

  • If  these rules are applied correctly, the one-time  pad can be proven unbreakable (see Claude  Shannon's "Communication Theory of Secrecy  Systems"). Even infinite computational power  and infinite time cannot break one-time pad  encryption, simply because it is mathematically  impossible. However, if only one of these rules  is disregarded, the cipher is no longer  unbreakable.

     
     
    • The key is at least as  long as the message or data that must be  encrypted.
     
    • The key is truly random  (not generated by a simple computer  function or such)
     
    • Key and plaintext are  calculated modulo 10 (digits), modulo 26  (letters) or modulo 2 (binary)
     
    • Each key is used only  once, and both sender and receiver must  destroy their key after use.
     
    • There should only be two  copies of the key: one for the sender and  one for the receiver (some exceptions  exist for multiple receivers)
     
     

    Important note: one-time pads  or one-time encryption is not to be confused with  one-time keys (OTK) or one-time passwords  (sometimes also denoted as OTP). Such one-time  keys, limited in size, are only valid for a  single encryption session by some  crypto-algorithm under control of that key. Small  one-time keys are by no means unbreakable,  because the security of the encryption depends on  the crypto algorithm they are used for.
  • One-time pad encryption is only  possible if both sender and receiver are in possession of  the same key.
• 13 Aug 09
  

  Jonathon Richter

  onetimepad spies games

• 04 Apr 08
  

  Robert Talbert

  cryptography crypto encryption delicious-import

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