What happens if I code sign an applet with a valid certificate which has expired in the meantime?
Netscape’s tools won’t let you sign an applet with an expired certificate. However, Navigator will treat an applet signed with a currently-expired certificate the same as an applet signed with a still-valid certificate. Microsoft’s tools allow you to attach an unforgeable timestamp to your archive. Archives which were timestamped and signed with valid certificates will be treated as secure even after the certificate expires; archives that were not timestamped or were timestamped after the certificate had expired will be reported as suspect.