Advanced – Security Testing
Mutual TLS (mTLS) – ISTQB Definition
Last Updated: July 12, 2026 · SoftwareTestPilot QA Team
Official ISTQB Definition
A variant of TLS where both client and server authenticate each other with certificates.
In simple words
TLS where both sides prove who they are with certificates.
Exam tip
mTLS is common in zero-trust and service-mesh architectures.
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