REST API stands for Representational State Transfer Application Programming Interface. It is an architectural style for designing networked applications. REST is an approach that uses HTTP protocols to enable communication between different systems over the internet.

In a REST API, resources are identified by unique URLs (Uniform Resource Locators), and the API provides a set of operations or methods to interact with these resources. These operations include retrieving, creating, updating, and deleting resources.

REST APIs are stateless, meaning that each request from a client to the server contains all the necessary information to process that request. The server does not store any information about the client’s previous requests.

REST APIs use standard HTTP methods such as GET, POST, PUT, and DELETE to perform operations on resources. The API responses are typically in a format such as JSON (JavaScript Object Notation) or XML (eXtensible Markup Language).

REST APIs are widely used in web development and are the foundation of many modern web services and applications. They provide a flexible and scalable way to expose and consume data and functionality over the internet.

What is PKI?

PKI stands for Public Key Infrastructure. It is a system of technologies, policies, and procedures used to manage digital certificates and public-private key pairs. PKI provides a secure way to authenticate the identity of individuals, devices, and organizations in a networked environment.

In a PKI, a trusted third-party entity called a Certificate Authority (CA) issues digital certificates that bind a public key to a specific entity. These certificates are used to verify the authenticity and integrity of digital communications and transactions.

The main components of a PKI include:

1. Certificate Authority (CA): A trusted entity that issues and manages digital certificates.

2. Public Key: A cryptographic key that is publicly shared and used for encryption and verifying digital signatures.

3. Private Key: A cryptographic key that is kept secret and used for decryption and creating digital signatures.

4. Digital Certificate: A digitally signed document that binds a public key to an entity’s identity. It contains information such as the entity’s name, public key, and the CA’s digital signature.

5. Certificate Revocation: The process of invalidating a digital certificate before its expiration date. This can happen if the private key is compromised or if the entity’s information changes.

PKI is widely used in various applications, including secure email communication, secure web browsing (HTTPS), digital signatures, and secure access to networks and systems. It provides a foundation for establishing trust and ensuring the confidentiality, integrity, and authenticity of digital communications.