We will now analize another problem regarding asymmetric cryptography: how can I distribuite public keys? In order to distribute keys there must be someone that certify that this is really Marco’s key. To carry out this task there is an informatic structure called Certificate.
A certificate is issued by the authority of certification which distributes public key on the net and which assures that the public key belongs to a certain person. These certificates have the standardized abbreviation: X.509. The main features of a certificate are:
- It links a key to a personal and data processing (server) identity.
- It is issued by an authority of certification (CA)
- It has an expiry date
- It is revocable from both the user and the issuer
- It has the standardized abbreviation X.509
If you see on the web that the safety is assured by using certificates X.509, this means that you are dealing with programmes using these types of systems.
