How do you handle service-to-service authentication in microservices?

Service-to-service authentication is a security mechanism in microservices architecture that ensures the legitimacy of service callers, with the core objective of preventing unauthorized access and data leakage. In distributed systems such as e-commerce or cloud-native applications, it maintains communication integrity, reduces security risks, and ensures compliance.

Core components include token-based authentication (e.g., JWT), mutual TLS (mTLS), and API gateways. The principle involves identity providers issuing tokens or verifying identities through certificates. In practical applications, it is implemented automatically using Kubernetes service accounts or service meshes (e.g., Istio), enhancing security, implementing a zero-trust architecture, and strengthening isolation between microservices.

Processing steps: 1. Deploy an API gateway to centrally authenticate requests. 2. Configure mTLS to encrypt communication using digital certificates. 3. Integrate JWT verification logic into service code. Business value: Reduces the attack surface, ensures data privacy and compliance, and improves system reliability and scalability. Typical scenarios include the application of Istio service mesh in cloud-native platforms.