Thanks to Lazycat's great idea. He told us how to use the CallWindowProc API to run machine code. So I wrote some codes in Sphinx C--, and run them in AutoIt.   Here are MD5, SHA1, CRC32, RC4, and BASE64 algorithm in the attachment. (My CRC32 Code is a bit faster then Lazycat's version) SHA1_MD5_RC4_BASE64_CRC32.zip If someone needs other algorithm, please let me know, and I will try my best. If you are looking for SHA2 or AES, here and here.   2008/08/02 Update Note: Corrected Block TEA (XXTEA) block cipher is added. Take a look at Wikipedia for detail. SHA1_MD5_RC4_BASE64_CRC32_XXTEA.zip 2008/08/24 Update Note: Add a parameter $LineBreak to _Base64Encode(). This function will break output line in every 76 characters by default. Thanks to trancexx. SHA1_MD5_RC4_BASE64_CRC32_XXTEA.zip 2008/09/27 Update Note: Optimize machine code in _Base64Encode() and _Base64Decode(). Fix _Base64Encode() crash problem. Thanks to trancexx. SHA1_MD5_RC4_BASE64_CRC32_XXTEA.zip