Account takeover prevention
Reduce account takeovers with simple controls.
Credential stuffing runs on passwords your users reused somewhere else. LeakJar helps you catch those credentials and enforce the policy that breaks the attack chain — block, step up, or monitor.
Block
Block breached passwords at every entry point
Most account takeovers start with a credential that's already been compromised. LeakJar's Password Protect API lets you screen passwords at signup, change, and reset — blocking known-compromised credentials before they're ever accepted.
- Screen against 10B+ known-compromised password hashes
- Privacy-preserving k-Anonymity — no full hashes leave your infrastructure
- Sub-50ms p95 latency for seamless integration into auth flows
- Configurable policy: block, warn, or log for review
Step up
Trigger step-up authentication on risk signals
Not every matched credential needs to be blocked. For lower-risk scenarios or during gradual rollout, configure LeakJar to trigger step-up verification — adding a layer of assurance without disrupting the user experience.
- Require MFA when a breached password is detected
- Configurable per project, per flow, or per risk level
- Supports integration with existing MFA providers
- Gradual rollout support — start with notify, escalate to enforce
Monitor
Monitor for ongoing exposure
ATO prevention doesn't stop at the login form. LeakJar's Exposure Monitoring watches for credentials tied to your domains appearing in new breach data — giving your team the context to act before attackers do.
- Domain-scoped monitoring for your organization's email addresses
- Alerts routed to email, webhooks, or your incident response tools
- Severity context and recommended response actions
- Track remediation progress in the console dashboard
Build your ATO prevention strategy
Explore our policy documentation to see recommended configurations for different risk profiles.