A KEYGEN element allows a form to be submitted with key encryption, where the server expects a form to be packaged with an encrypted key. The client browser must have a digital certificate installed. The user sees two results of including the KEYGEN element inside a FORM element. First, a select list of available encryption key sizes is rendered in the form where the KEYGEN element appears. When the user submits the form, the user may see one or more security-related dialogs for confirmation. This element builds on the public-key encryption systems built into Navigator.

If the server is equipped to interpret a challenge string for verification of an encrypted package, the CHALLENGE attribute is the challenge string.

Encrypting a form turns the entire form into a value that is part of a name/value pair. The NAME attribute assigns the "name" part of the name/value pair. If the server successfully decrypts the package, the individual form element name/value pairs are available to the server for further processing.