Brian Dunning's FileMaker Custom Functions

Rot13 ( Text )

Easy ROT 13 encoding/decoding function. Uses Recursion.

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Christian Jaeger   Christian Jaeger
contact: cjaeger @
Hannover, Germany

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  Sample input:
Rot13("alea iacta est")
  Sample output:
nyrn vnpgn rfg

  Function definition: (Copy & paste into FileMaker's Edit Custom Function window)

ROT13 (Caesar-Cipher by 13 chars) is a cipher commonly used in Usenet postings. The term cipher itself might be a bit misleading: The ROT13-algorithm is based on a rotation of all alphabetic characters by 13. Speaking in computer terms the ASCII-values of the letters are incremented or decremented by 13.

In addition to ROT13, ROT5 is often used to encrypt digits, which means that every digit is rotated by 5.

The beauty of the ROT13 is that you can use the same formula to decrypt. This encryption method is found often on Usenet, and you can use it to hide somethings from your kids (if they are under 8 years of age) ;-)



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