Hey everyone. I am trying to make an instant messenger and I am worried about security. Currently I have all the messages in a "msgs" directory and each user has a txt file named username.txt and anyone can access anyones I need some way to have it so if someone goes directly into one of the text files they cant see what it says or mess with it. The same thing for the file with the passwords (all in one file) like a small code I can add to my scripts that will encrypt and another that can decrypt. If ANYONE can help make sure you E-MAIL me because I might not be able to check back at this forum so PLEASE e-mail me. THANKS!!! miketwalker@cfl.rr.com

Sorry I don't understand. How can they get "into" a text file?

Installations:http://www.wiredon.net/gt/

By simply going to the url that the text file is at like http://www.theurl.com/whatever.txt They can see everything in there but if I can encrypt everything being written such as messages it will be a bunch of coding so they wont understand what is in the file. But in the same fashion I need to be able to decrypt it for when the user comes in so they can read the messages. Do you see what I mean now?

When the program creates the .txt files, just have it set permissions 755. Then no one can view them. Just use something like this:

chmod(0755,$filebeingcreated);

The thing is, what happens when the user logs in to there messenger account and wants to see what is in that text file because that text file has there messages.

It will still be able to read the file. Why don't you just test it? Chmod one of the user files to 755 and then log in as that user and read your messages...

Another thing, do you know how to encrypt and decrypt though I mean for the passwords in the users file as added security.