Intermediate LevelAuthentication & Authorization
How does Contextual Risk-Based Authentication adjust security policies based on IP/Location/Device?
❓ Interview Prompt: Explain Risk-Based Authentication (RBA), risk scoring engines, impossible travel velocity, and adaptive MFA challenges.
Static authentication treats a login request from a user's normal home laptop the same as a login request coming from an anonymous Tor exit node in a foreign country. Contextual Risk-Based Authentication (RBA) dynamically assesses risk.
Risk Signals Evaluated:
1
Impossible Travel Velocity: User logs in from New York, then 10 minutes later logs in from Tokyo.
2
New Device / User-Agent Fingerprint: Login from an unrecognized browser/device pair.
3
Reputational IP Score: Login from known botnets, VPNs, or datacenter IP blocks.
Adaptive Policy Actions:
•
Low Risk (Score < 20): Grant seamless access.
•
Moderate Risk (20 - 70): Trigger mandatory Step-Up 2FA / WebAuthn prompt.
•
High Risk (Score > 70): Block access immediately and email security alert.
Code Implementation Example
typescript
function evaluateLoginRiskScore(ctx: { isNewDevice: boolean; isTorIp: boolean; milesPerHourTravelled: number }): 'ALLOW' | 'MFA_REQUIRED' | 'BLOCK' {
let score = 0;
if (ctx.isNewDevice) score += 30;
if (ctx.isTorIp) score += 60;
if (ctx.milesPerHourTravelled > 600) score += 80; // Impossible travel!
if (score >= 80) return 'BLOCK';
if (score >= 30) return 'MFA_REQUIRED';
return 'ALLOW';
}💡Contextual risk engine scoring login attempts and assigning adaptive security policies.
🎯 Interview Key Takeaway
Contextual risk authentication dynamically triggers MFA challenges or blocks logins based on real-time threat signals.
#Risk-Based Auth#Contextual Security#Adaptive MFA#Intermediate
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