HTTPS (Hypertext Transfer Protocol Secure)

An extension of HTTP. It is used for secure communication over a computer network, and is widely used on the Internet.

HTTPS is the secure version of HTTP, using TLS (Transport Layer Security) encryption to protect data in transit between the client and server. HTTPS ensures three key security properties: confidentiality (data cannot be read by intermediaries), integrity (data cannot be modified in transit), and authentication (the server's identity is verified through its TLS certificate).

HTTPS requires a valid TLS certificate issued by a Certificate Authority (CA). Certificates can be obtained from providers like Let's Encrypt (free) or commercial CAs. The TLS handshake establishes an encrypted connection before any HTTP data is exchanged. Modern best practices mandate HTTPS for all web traffic, not just pages handling sensitive data.

For APIs, HTTPS is essential. All API traffic should be encrypted to protect API keys, authentication tokens, and payload data. API gateways typically handle TLS termination, decrypting incoming HTTPS requests and forwarding them to backend services over internal networks. This centralizes certificate management and offloads the computational cost of encryption from backend services.