Certificate

A certificate is a digitally signed proof by a trustworthy third party certifying that a certain public key belongs to a certain user. In addition to a public key, the certificate also includes other information, such as the name of the person or organisation, date of issue, expiration date or an individual serial number. One of the most commonly used structures of certificate is described in the ITU-T recommendation x.509v3.

Certificates can be divided for instance to the following categories:

Personal certificate

A certificate intended for the use of a private person. The personal certificate links the public key with the person using it.

Role certificate

The terms job-, office- and organisation certificate are also used. The role certificate is otherwise equal to a personal certificate but it links the public key to a user acting in some role (e.g. referee, acceptor) or in a certain job (medical doctor, teacher etc.).

Qualified certificate

A certificate that meets the requirements set in the Act on Electronic Signatures (14/2003) and has been granted by a certifier in compliance with the Act.

Server certificate

A certificate intended for instance for the use of a web server by means of which the user may ensure the authenticity of the server (s)he is dealing with.