Cryptography 101

  • By Melissa Salpietra
  • Posted 07.01.07
  • NOVA scienceNOW

You can make a message secret in countless different ways. One common way is to use a substitution cipher, in which one letter is substituted for another. Another is to employ a transposition cipher, in which the letters change position within the message. In this interactive, explore examples of a substitution cipher and two kinds of transposition cipher.

Launch Interactive

Learn different ways to make a message secret.



© NOVA/WGBH Educational Foundation

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