How do public key infrastructures (PKI) support network security?

Public Key Infrastructures (PKI) enable secure communications and authentication for network security by utilizing asymmetric encryption to establish trust and secure communication channels. In a PKI system, each entity is assigned a unique key pair: a public key for encryption and a private key for decryption. The public key can be shared openly, while the private key is kept secret.

PKI enables secure communications through the following steps:
1. Certificates: PKI issues digital certificates that bind an entity’s public key to their identity. These certificates are digitally signed by a trusted Certificate Authority (CA), establishing the authenticity of the public key.

2. Encryption: Entities can encrypt messages using the recipient’s public key. Only the corresponding private key can decrypt the message, ensuring confidentiality.

3. Authentication: Public keys are used for digital signatures to authenticate the sender’s identity. The recipient can verify the signature using the sender’s public key.

4. Secure Socket Layer/Transport Layer Security (SSL/TLS): PKI is integral to SSL/TLS protocols used in secure web communication. It ensures that the server is authentic, and data exchanged between the server and client is encrypted.

5. Secure Email: PKI enables secure email communication through digital signatures and encryption, ensuring message integrity and confidentiality.

Overall, PKI establishes a trusted framework for secure communication, authentication, and data integrity in network security.