What is PTERI?

PTERI (the Privacy Trust Engine) is Kakr Labs' platform for identity and authorization — for people, AI agents, and existing enterprise systems. Instead of passwords, API keys as bearer secrets, or "trust once, allow forever" sessions, PTERI verifies every identity and authorizes every sensitive action with a cryptographic signature, produced at the moment the action happens.

The core idea: if a secret can be typed, it can be phished; if it can be stored, it can be breached. PTERI replaces that model with challenge–response signatures from a key that never leaves your device.

What PTERI actually does

• Authentication — signing in is a signed challenge from your device key, gated by biometrics, not a password
• Authorization — sensitive actions (payments, role changes, deletions) require a fresh signature over the exact action being taken, so the proof and the approval are the same thing
• AI agent identity — agents can hold their own cryptographic identity and be required to produce a valid signature before acting, instead of inheriting a human's static credentials
• Developer APIs & SDKs — a REST API and client SDKs for building identity, authentication, and authorization flows into your product

The technology

Private keys are generated and held entirely on your device — Kakr Labs' infrastructure can verify a signature but never sees, stores, or can reuse the key that produced it.

See how authentication works and how authorization works for the concrete mechanics.