Overview: Public key cryptography revolutionized secure communication by introducing two distinct keys: a public key for encryption and a private key for decryption. This method eliminates the need for both parties to share a secret key, making secure communication more feasible.
Security Properties:
The public key can be shared openly without compromising security, as the corresponding private key is never shared.
It is computationally infeasible to derive the private key from the public key, ensuring the security of the encryption process.
Public Key Infrastructure (PKI)
Definition: A comprehensive framework that encompasses the technologies, policies, and procedures required to manage digital certificates and public key encryption. PKI enables secure communication over networks.
Digital Certificates: Electronic documents that bind a public key to an entity’s identity, providing assurance of the key owner’s legitimacy. Digital certificates include:
The subject’s name, a unique serial number, validity dates, the public key, and the digital signature of the issuing Certificate Authority (CA).
Certificate Authorities (CAs): Trusted entities responsible for issuing and managing digital certificates. They validate the identity of certificate applicants and provide assurance that public keys belong to the specified entities.