Access webstorage from outside

I try to set a score to webstorage, I tried both local storage and session storage.

I would like to set the score, redirect the page and then access the session/local variable using javascript.

It should be like SessionStorage.getItem("score")

but not working, anyone?

Local Storage is domain-based.

I think it needs to create new plugin which allows cross domain using XAuth.

If the new page is still on your domain, you can access it through Javascript using session storage with the same key names as used in C2.