Re: Planing a browser plugin. Worried about cookie security.
Sounds like you're going about designing your security wrong.
How do you plan on implementing it? How will it be used in your plugin? If you can give us a diagram or chart maybe me or someone else can help you. You don't have to reveal your plugin to us but some knowledge of how stuff works could help.
On your issue about interception. Anything can be intercepted. Spoofing is possible also. It's unlikely though. But security through obscurity is never a good thing.
Windows: A thirty-two bit extension and GUI shell to a sixteen bit patch to an eight bit operating system originally coded for a four bit microprocessor and sold by a two-bit company that can't stand one bit of competition.