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 FileMaker Pro Custom Functions

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ChaosEncrypt ( text ; key )

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  Average rating: 4.5  (31 votes)
  Discuss this Custom Function

Jeremy Bante,

Encrypt text with a chaos-based stream cipher

Sample Input:
ChaosEncrypt ( "The original text" ; "The super-secret key" )
Sample Output:

 Then copy & paste into FileMaker Advanced's Edit Custom Function window.


ChaosEncrypt ( text ; key ) uses chaotic permutations of key to create an encrypted version of text that is extremely difficult to retrieve without the original key. This function uses a pseudo-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.

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

This is my Custom Function and I want to edit it


5 most recent comments | Show all 10 comments

Thanks, Jeremy, for the quick answer. I’m also trying to figure it out and I’ll keep you informed of the results.

Jose, Ferreira
June 01, 2011 2:25am

Have tried this function and am finding it flawed. I encrypted 7000 credit card numbers and some 2% are not encrypted correct. Long or short keys make no difference (although the shorter the key the less gets encrypted correctly).
I've used a key 3 or 4 times the size of a CC number, exactly the same length as a CC , makes no difference. Some numbers in CC's will cause issues for this encryption function.
Using FM13.

Olger, Gold Coast, Australia
July 18, 2014 4:07am

Please do not use this function to encrypt credit card numbers. It has not been subjected to a substantial amount of cryptanalytic scrutiny. Use a more rigorously analyzed and tested algorithm instead, such as AES 256.

Jeremy, USA
July 18, 2014 7:56am

We are trying to use this to encrypt customer and project names to a distributed mobile workforce. The problem is that of the 125 records encrypted, some of the customer names or project names are not decrypting properly. Total error rate is 12 errors. We can't find any pattern in the text that is problematic. Will this work on any and all text?

Steve S, Indiana
November 24, 2014 1:11pm

Steve, I've done a fair amount of testing, but the space of possibilities is too big for me to test everything. Other folks have found issues before related to nuances of text encoding that I was previously ignorant of. I'm not surprised you're running into more. Send me an email (check the scrim link in the header comment) if you're comfortable sharing some examples with me that I can look at in more detail.

That said, you shouldn't be using this function if you need a lot of confidence in the security of your solution. I wrote this encryption scheme for fun because I was bored with work one week; it has not been subjected to significant cryptanalytic scrutiny. You should consider using FileMaker 13s new encryption at rest feature, which is much more secure.

Jeremy, USA
November 24, 2014 6:31pm

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