Proof a real human did the work.
Bitcoin's proof-of-work proves a machine spent computation. 5arz's Proof of Work proves the opposite — that a real, unique, attentive human performed a specific task. Every unit comes with a cryptographically signed credential anyone can verify.
Machine work vs. human work
Classic proof-of-work
Proves a machine burned energy on computation. Useful for blockchains — silent on whether a human was involved at all.
5arz Proof of Work
Proves a real, attentive human performed a specific task — a label, rating, demonstration, or real-world action. A credential, not a consensus mechanism.
Why it's scarce now
Bots are the majority of internet traffic and a large share of crowdwork is secretly LLM-generated. "A real human did this" has become the hard signal to prove.
How it works
Identity + on-device liveness. Biometrics never leave the device.
The human completes the task — cognitive (label, rank, moderate) or kinetic (a real-world action).
5arz issues a Proof-of-Human-Fulfillment credential — an ES256 JWT with a quality score and tamper-evident telemetry.
Anyone validates the credential against 5arz's public JWKS. No 5arz SDK required.
Where verified human work matters
AI training data & RLHF
Provenance that a real human produced each label, ranking, or evaluation — clean human data AI teams can trust and audit.
Agent-commissioned work
When an AI agent pays for human work, the credential proves a real human actually did it — the fulfillment half of agentic commerce.
Marketplaces & freelance
Attach proof-of-human to delivered work so buyers get a clean chain of title to authentic human output.
Field & kinetic work
Capture proof of a real-world action — a delivery, an inspection, an on-site task — as a verifiable Proof-of-Human-Fulfillment record.
Pricing — pay per verification
One prepaid balance is shared across Proof of Work and Proof-of-Personhood checks. Enterprise pricing with SLAs available.
FAQ
What is proof of work for humans?
Verifiable evidence that a real, unique, attentive person performed a specific task — a label, rating, demonstration, or real-world action. 5arz issues it as a cryptographically signed credential anyone can verify.
How is this different from Bitcoin proof-of-work?
Bitcoin proof-of-work proves a machine expended energy on computation. 5arz Proof of Work proves a real human — not a machine or an LLM — did the task. It's a credential, not a consensus mechanism.
Why does it matter for AI training data?
A large share of crowdwork is secretly LLM-generated. A signed provenance record that a real human produced each unit lets AI teams trust the human data they pay for.
How do I verify a credential?
Each credential is an ES256 JWT. Validate it against 5arz's public keys at api.5arz.com/.well-known/jwks.json with any standard JWT library.