I have a hidden input on my form, and my JavaScript code writes there dynamically generated string based on the user behavior on the page.

Later, I access to that inpput via server side code.

**Many users will be using this page at the same time**, so what about thread safety ?

I mean, could it be possible that userA has an access to that string generated by userB ? Or maybe server will read that string from each user's Web Browser ?