Signed JavaScript

Netscape Navigator 4 and later versions support digitally signed scripts that can request privileges, and, subject to user approval, lift certain security restrictions while executing. A digital signature allows the browser to securely establish the author of a signed JavaScript program (see [N98]). Cryptographically signed scripts are not yet very popular, partly because average users find it hard to grasp the privilege-granting process or the implications of granting a particular privilege.

For future versions of browsers we propose to integrate code signing into our model, by having specific security policies that go into effect if a signed script is downloaded from a particular site. For example, a Fidelity policy for the user's interaction with the brokerage house might allow reading and writing files in a specific directory, so that the user can study his account offline.