Brian Dunning's FileMaker Custom Functions

ChaosDecrypt ( cipherText ; key )

Decrypt text enciphered by the ChaosEncrypt() function

  Average rating: 4.1 (35 votes) Log in to vote

Jeremy Bante   Jeremy Bante

https://github.com/jbante/

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  Sample input:
ChaosDecrypt ( "蔿괴㼀ኒጏ륮縤ᖙ㇤ヰꣿ톃鋦⛤簘" ; "The super-secret key" )
  Sample output:
The original text

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

Uses chaotic permutations of the key to create an decrypted version of cipherText that was created by the ChaosEncrypt() function. This function uses a psuedo-chaotic stream cipher algorithm adapted to the constraints of FileMaker custom functions.

This function has not been subjected to rigorous cryptanalysis, and the author does not warranty the security of encrypted text.

Newer versions of this function are very unlikely to be backwards compatible.

 

Comments

Bob Stuart   Bob Stuart, Noosa, Queensland, Australia
Jan 21, 2011
Nice work, Jeremy, but in encrypting and decrypting this text: PLEASE READ THIS LICENSE CAREFULLY BEFORE USING THIS SOFTWARE. BY USING THIS SOFTWARE, YOU AGREE TO BECOME BOUND BY THE TERMS OF THIS LICENSE.

I could only get it to go this far:
PLEASE READ THIS LICENSE CAREFULLY BEFORE USING THIS SOFTWARE. BY USING THIS SOFTWARE, YOU AGREE TO BECOME BOUND BY THE TERMS躠틗ᣠ辶駉駓馠駌駉駃駅駎駓駅馮

If it could Encode/Decode a larger chunk, it would be REALLY useful to me.

Regards,

Bob Stuart
Think Data
Noosa
Queensland
Australia.
bobstu@thinkdata.com.au
 
Jeremy Bante   Jeremy Bante, San Mateo, CA, USA
Jan 21, 2011
It looks like you found a bug in the creation of the decryption keystream. Thank you for catching this. I'll look in to it this weekend, and let you know when I have it fixed.
 
Jeremy Bante   Jeremy Bante, San Mateo, CA, USA
Jan 23, 2011
Fixed it! It turned out to be a problem with handling composite characters, and didn't have anything to do with the length at all.
 
Olly   Olly, London, UK
Jan 25, 2011
Very cool. Esp for FMGO.

Thanks for these Jeremy.
 
P Sanchez   P Sanchez, Jacksonville, FL
May 17, 2011
encryption works well. When I use the decryption using the same key, I get this...爵

any ideas?
 
Jeremy Bante   Jeremy Bante, San Mateo, CA
May 17, 2011
Would you be willing to send me the original text and your key, so I can take a closer look at it? http://scr.im/jbantetsg
 
P Sanchez   P Sanchez, Jacksonville, FL
May 17, 2011
just a made up SSN# 001-22-3333 and the key was 10 (record ID). I was just testing this in the script, so I kept it real simple.
 
P Sanchez   P Sanchez, Jacksonville, FL
May 17, 2011
I should specify that the script is basically, set variable of $value; ChaosDecrypt and then a set field step to set this $value into my field.
 
Jeremy Bante   Jeremy Bante, San Mateo, CA, USA
May 17, 2011
So are you encrypting "SSN# 001-22-3333", "001-22-3333", or "001223333"? I wont get a chance to look into this until tonight, but I'll let you know what I find and update this page with any fix I come up with.
 
Paula Sanchez   Paula Sanchez, JACKSONVILLE
May 17, 2011
Yep. I tried both with and without the dashes. Neither worked on the decryption. Not sure if I am doing something wrong or not...
 
Jeremy Bante   Jeremy Bante, San Mateo, CA, USA
May 23, 2011
For the public record, Paula and I looked into the issue, and it turned out that there was nothing wrong with the function.
 
Brian Donovan   Brian Donovan, Mexico
Feb 21, 2015
very good code! excellent! found no bugs will post if I do!
 

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Note: these functions are not guaranteed or supported by BrianDunning.com. Please contact the individual developer with any questions or problems.

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