Microsoft's Authenticode model is somewhat simpler than the Communicator model for the end user. Assuming the user doesn't know anything about zones, lots of stuff runs without asking the user for permission; the user is prompted only to approve code generally when the code requests full access, and doesn't already have permission. Less interaction generally means less hassle for the user. You can make more dialog boxes disappear if you check boxes like, "always trust code from this person," and "always trust code from this site," which appear in the window that announces that code is trying to gain permissions. However, spreading trust around so easily just to avoid dialog boxes can have bad consequences.
Authenticode is also simpler for the developer. There's no need for calls to a Capabilities library, meaning you can simply request an access level, as opposed to requesting a set of privileges. However, Netscape is capable of finer-grained access control, which allows the applet to secure only the resources it needs to run without a user feeling the need to give a program complete access to the computer.
Another convenience of Authenticode over Object Signing is that the user only gets prompted at most once per applet. Netscape prompts the user whenever new privileges are requested (which is usually during execution). While the Netscape model is more intrusive, it does afford the user a bit more control over what privilege is granted to an applet.
Copyright ©1999 Gary McGraw and Edward Felten.