You will need a digital certificate to register for this service.

There are also several providers issuing digital certificates to the public at no cost.

One of these requires you to have a digital certificate.

This information is held in an individual's digital certificate.

It also includes a Wizard to get a free digital certificate, as well.

This key is made publicly available, generally in the form of a digital certificate.

The public key is made available to anyone (often by means of a digital certificate).

Every other application, like messages and digital certificates, can go wireless.

For more details, see the page in this guide on digital certificates.

It is imperative that you as contractors keep your digital certificates current.