Public key infrastructure

The public key infrastructure (PKI) is a kind of model for administration of public keys and certificates.

The PKI uses asymmetric encryption methods based on keypairs in such a way that the basic requirements of secure e-business can be met: digital signature with the signer’s private key and encryption of messages with the recipient’s public key.

Confidence is an essential part of the PKI model. In order that two parties previously unknown to each other could communicate with confidence, a third party is needed to assure the identity of these parties. In the PKI model the confidence is based on a certification authority acting as a third party trusted by both the communicating parties. In the certificate granted by the certification authority, the certification authority combines the public key with its holder. Thus confidential communication and digital signatures will be possible even in the case when parties don't know each other beforehand.