You're going to need Beege's Base64 UDF and Ward's AES UDF. Beege's Base64 UDF - Base64.au3 Original Thread: https://goo.gl/H1QqEG Ward's AES UDF - AES.au3 Original Thread: https://goo.gl/zQdASR Ward's UDF is amazing, but I felt the need to make a few "Helper" functions to make things easier. _Encrypt() and _Decrypt(), accepting 1 parameter and using a randomly generated IV for encryption, making the end encryption string dynamic and never the same. It pulls the IV from the first 16 characters of an encrypted string for the _Decrypt() routine. EncryptionExample.au3 Now for the PHP goodies! First, we have a required include Encryption.php which was compiled by me. And, finally, an example of the PHP side of things. EncryptionExample.php /EncryptionExample.php?Action=Decrypt&Text=W4NAKRzuuTOfl9pAE8kSUgMYcuosvbUy58GR9w46U8w= Should output something like this: