Laan's steps..

from:http://www.actionscript.org/forums/showthread.php3?p=942890

After some googling, I found some opinions about obfuscaters by Amayeta and Kindisoft. Developers say kindisoft’s secureSWF works better and I bought a personal version for my projects.

secureSWF does nothing at all and its price is $99. Kindisoft offers code obfuscation only for $199. Too much for this kind of software.

Now i’m going to get my money back and i’m testing other obfuscators’ demo versions.

Eramsoft Flash Secure Optimizer ($50) – renames identifiers and classes to numbers with “_”. Good, my game is working. (By the way, the game is a simple platformer). Sometimes encrypted file crushes last Sothink SWF Decompiler.

irrFuscator (flash+flex, $102 or $222) doesn’t rename classes, and obfuscated game sends tons of errors.

toKaos ($120) encrypts fla and mxml, not swf. Waste of time.

Dcomsoft SWF Protector ($40-$300) does not obfuscate at all! Just crushes Sothink SWF Decompiler.

.DoSWF ($10, $15 or $60) does something strange with my swf’s structure (see attachments). Sothink crushes and can’t extract anything, even images and sounds! Game works properly.

To sum up:
IMHO, asian guy with his AIR-based DoSWF is the winner. It costs only 10-15 dollars and works very well. None of the other programs can hide SWF’s resources.