What is mTLS (Mutual TLS)?

Regular TLS only verifies the server (your browser checks the website certificate). Mutual TLS (mTLS) verifies both sides — the client presents a certificate too, and the server verifies it.

Why mTLS for Microservices?

In a Kubernetes cluster, services communicate over the internal network. Without mTLS, this traffic is unencrypted and unauthenticated — any compromised pod can eavesdrop or impersonate. mTLS provides encryption (confidentiality) and mutual authentication (identity verification) on every connection.

mTLS with SPIFFE

SPIFFE provides the certificates (X.509-SVIDs) that mTLS uses. SPIRE manages the issuance and rotation automatically. Service meshes like Istio and Envoy handle the TLS handshake transparently as a sidecar proxy.

Learn More

See Zero Trust Fundamentals for hands-on mTLS implementation.