PKI, which stands for Public Key Infrastructure, is a comprehensive system that consists of policies, procedures, hardware, software, and cryptographic algorithms that are used to manage digital certificates and encryption keys. It is a framework that guarantees secure communication by providing authentication, confidentiality, integrity, and non-repudiation.
In a PKI, a trusted third party, known as the certificate authority (CA), plays a central role. The CA is responsible for verifying the identity of individuals, organizations, or devices and issuing digital certificates that bind these identities to their public keys. These certificates are then used for multiple purposes, such as establishing secure connections, encrypting data, and digitally signing documents.
The infrastructure of PKI is built upon a hierarchical structure where the root CA is at the top and is responsible for issuing certificates to subordinate CAs, intermediate CAs or end-entities. The certificates issued by the CAs are based on asymmetric cryptographic algorithms, which involve a pair of mathematically related keys – a public key used for encryption and a private key used for decryption or digital signing.
By utilizing PKI, organizations can ensure secure communication and protect against unauthorized access or tampering of sensitive information. It is widely used in various applications, including secure email, online banking, e-commerce, virtual private networks (VPNs), and digital signatures. PKI plays a crucial role in building trust and establishing secure connections in the digital world.
