I have a small request. I am using the encryption and want to know through the ETNA_GetState function whether the authentication was worked. Could there be a new state that flags the fact that authentication failed?
I am not sure to understand what you want. First, on the ETNA side, the encryption NEVER failed. ETNA always encrypt successfully any string. On the php side, if the encryption key is the same, there is no reason for the php script to fail. When the authentication does not work, this is because of a mistake from the user (I know, I did some!). Could you explain me why you are thinking about this?
Does the encryption stop anyone from calling the .php script direct with values? Imagine they want to post to the online scores database, could they do it if the encrpytion is on. What actually gets transmitted?
If the php is using encryption, then it can not receive any arguments without encryption. Because the php will think the arguments are encrypted, it will decrypt it, and of course the arguments will be completely messed up. What is sent to the php is a string of type "3F4503A3E4FE" (encrypted), but if you send "&score=12" without encryption, the php script will mess it up. It's possible to have a php script which understand BOTH encrypted or non encrypted arguments, but this means that encryption is completely useless, as anyone could send normal arguments to the php. ETNA does not allow that.
I hope I was clear enough...