# adaptive-auth

Source: https://startwithidentity.com/glossary/adaptive-auth/
Last updated: 2026-08-29
License: content by Start with Identity. Cite the source URL.

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Authentication flows that change based on risk signals. Low-risk sign-ins may complete with one factor; high-risk sign-ins escalate to step-up MFA or are blocked. Synonym in most contexts: risk-based authentication.

The value of adaptive authentication is that it lets you raise assurance without raising friction for everyone, which is the only way strong controls survive contact with a consumer funnel. The risk is that the signals are mostly heuristics: IP reputation, geo-velocity, and device fingerprints all degrade as attackers use residential proxies and real browsers. Treat risk scoring as a way to decide when to demand a phishing-resistant factor, not as a replacement for one.

See also: [risk-based auth](https://startwithidentity.com/glossary/risk-based-auth/), [conditional access](https://startwithidentity.com/glossary/conditional-access/), [step-up auth](https://startwithidentity.com/glossary/step-up-auth/), [device posture](https://startwithidentity.com/glossary/device-posture/)