When configuring PKI, go to these sections for information you are interested in:
Introduction to PKI
PKI Configuration Task List
Displaying and Maintaining PKI
PKI Configuration Examples
Introduction to PKI
This section covers these topics:
Architecture of PKI
Applications of PKI
Operation of PKI
The Public Key Infrastructure (PKI) is a general security infrastructure for providing information security
through public key technologies.
PKI, also called asymmetric key infrastructure, uses a key pair to encrypt and decrypt the data. The key
pair consists of a private key and a public key. The private key must be kept secret while the public key
needs to be distributed. Data encrypted by one of the two keys can only be decrypted by the other.
A key problem of PKI is how to manage the public keys. Currently, PKI employs the digital certificate
mechanism to solve this problem. The digital certificate mechanism binds public keys to their owners,
helping distribute public keys in large networks securely.
With digital certificates, the PKI system provides network communication and e-commerce with security
services such as user authentication, data non-repudiation, data confidentiality, and data integrity.
A digital certificate is a file signed by a certificate authority (CA) for an entity. It includes mainly the
identity information of the entity, the public key of the entity, the name and signature of the CA, and the
validity period of the certificate, where the signature of the CA ensures the validity and authority of the
certificate. A digital certificate must comply with the international standard of ITU-T X.509. Currently, the
most common standard is X.509 v3.
This manual involves two types of certificates: local certificate and CA certificate. A local certificate is a
digital certificate signed by a CA for an entity, while a CA certificate is the certificate of a CA. If multiple
CAs are trusted by different users in a PKI system, the CAs will form a CA tree with the root CA at the top
level. The root CA has a CA certificate signed by itself while each lower level CA has a CA certificate
signed by the CA at the next higher level.