Key pair

The combination of a private and public key is called a key pair for the reason that these two numbers are related to each other by a non reversible mathematical function. In particuliar, the private key cannot be computed by knowing the public key.

Digital certificate

A digital certificate is the equivalent of an official identification document such as a passport for example: it contains information which identifies the certificate's incumbent, its personal signature (the public key), information relative to the issuing authority and other miscellaneous information such as the purpose of the certificat (i.e. signing emails, authentication, etc.).

Private key

Set of digits representing the digital equivalent of the way to write a written signature. The private key must always be ciphered so as to be always kept under the sole control of its owner.

Public key

Set of digits representing the digital equivalent of the image of the written signature. This key can be known by all, but does not contain information on its owner. See certificate.

P12

This term is commonly used to designate a file with a .p12 extension. It contains a certificate and the corresponding ciphered private key of its incumbent.