store API response data in first page and access in another page after reloading the page Polymer

I get a sign in Response on the first page which I store in a Javascript local variable and I will pass the same data to the second page it works fine until I reload the second page, but when I reload,the data which I got from the first page is destroyed.Storing the entire response-data in local storage is not good practice,If I store that data in session storage even anyone can modify data, So where we can store secured response data which I need in entire application and also which will not destroy when page is reloaded?