Mutual TLS.
also: mTLS · mutual TLS authenticationTLS where both sides present certificates: the server verifies the client too, so service identity is proven both ways.
the two-minute refresher
- Standard TLS: only the client checks the server. mTLS: the server also checks the client's certificate.
- Common for service-to-service traffic and partner APIs.
- Service meshes (Istio, Linkerd) issue and rotate the certificates automatically.
- A building block of zero trust: identity, not network location, grants access.