Technically, a ____ is a data structure used in a public key system to bind a particular, authenticated individual to a particular public key.

When using an Excel worksheet as a data source, each ________ represents a field

Fill in the blank(s) with correct word

Suggest a scheme that improves on MobileIP for providing access to a web server on a mobile device which is sometimes connected to the Internet by mobile phone and at other times has a wired connection to the Internet at one of several locations.

What will be an ideal response?