I've decided to make an addon that will provide users with an option to encrypt the data that they save, so they will need to provide the password to retrive the data.

I'm not that good with encryption, but I know some basics.

I'd appriciate any examples, or tips (note: I don't want to need to use a DLL).

Thanks in advance.

Example just in case:

3 or 4 people use the same computer, same mIRC, ect.
#1 dosen't want the others to use his data, but he has no way of encrypting it. (I.E a auto-id script, with his password stored.)
#2 finds out #1's password and 'acts' like he is #1 and messes some things up.

With the script, #1 could encrypt the data, and hinder #2 or any of the others from using his auto-id (just the data would need to be encrypted.

That still wouldn't be fool proof. Anyone that's able to look at the script code, could easily figure out how to backtrack it, and get the actual password. Windows allows you to set different logins that's able to protect your files. Don't share window logins, and you should be fine, unless one of the users has administrative rights. And if that's the case, don't store your passwords.

I am aware of that, but in the case of one being an administrator, that is the purpose of the script.
It could also redownload the .mrc file that handles the password each time (and delete it after its done) to prevent it from being modified (assuming that the script wouldn't exeed a few KBs, could also archive it).

You can encrypt files using something as simple and pkzip just password the files

If u want to do it all in scripting, then you could just allow them to enter a password, then xor the file using the byte values of the password (or a hashed value from it)