.Actionscript code inside swf cannot be encrypted . The flash player reads the code and then executes it on runtime. An encrypted code cant be readable by flash player. There are some software's that can modify variables and functions inside the code so that its hard to read and understand but again this is not something foolproof. There is no guarantee that your code will work perfectly after that.

There are some ways mentioned in a similar thread :
http://askmeflash.com/qdetail/1362/protect-swf

Thanks for ur answer Greg. I agree with you, What do u think about

http://www.amayeta.com/software/swfencrypt/trial/

I am intend to buy this...pls suggest me...


Thank you

I would recommend you to first use the trial product and see if your files work fine after encryption. This is also not a 100% secure solution, as I said its not possible to make it 100% secure but you can just make it hard to read. This is what this software is also doing.I have not used it personally so can't tell you how successful it is.As they have say , if the files encrypted by there software cannot be decompiled by most decompilers available in market then it will help a lot. See this link from there website.

http://www.amayeta.com/support/faqs/?id=1

Thanks Greg...

I like DcomSoft's SWF Protector 3 Works against 100% of everything I have thrown at it. Amayeta is expensive. You can test a free version here http:/www.dcomsoft.com