ACTOR TRUST RECEIPT
Illustrative- Actor
- Human
- Personhood
- Verified
- Identity
- Verified privately
- Presence
- Continuous
- Human control
- High confidence
- AI involvement
- Low
- Session continuity
- High confidence
Proof of Human
Proof of Human is the human-verification primitive of Proof of Actor: a proposed way for an application to obtain evidence that a real, present human is behind a digital interaction, with identity optional and disclosure limited to what the application needs.
The problem
Why human verification needs rethinking
For two decades, online human verification meant a CAPTCHA: a puzzle that was easy for people and hard for software. That gap has narrowed sharply. Capable AI systems can read distorted text, label images and move a cursor convincingly, while the puzzles grow harder for the people they are meant to admit.
At the same time, the question services need answered has changed. Some automation is now legitimate: an assistant acting for its user should not have to pretend to be a person. What a community, marketplace or poll needs to know is not whether a visitor can solve a puzzle, but whether a real, unique human stands behind an account or an action, and whether that is still true later.
Proof of Human treats humanity as evidence to be established, not a challenge to be passed once. It is one layer of the wider Actor model, and it deliberately separates being human from being identified.
What it establishes
What Proof of Human is designed to establish
Personhood
Evidence that a real human exists behind the interaction, rather than a script, a farm of synthetic accounts or an unattended agent.
Uniqueness, where it matters
For voting, promotions and anti-Sybil systems, evidence that one human is not operating many accounts, without building a public register of people.
Presence
That the human is present now, not that someone passed a check at some earlier point in the session.
Identity, only if required
An optional link to a verified identity, disclosed privately. Many use cases need "verified human, identity undisclosed" and nothing more.
Evidence, from more than one signal
Proof of Human is designed to be signal-agnostic and multi-signal. Families of evidence the architecture is being built to reason over may include:
We publish what is established, not how. Scoring, signal weightings and detection techniques are not disclosed.
Same primitive, different policies
- Community sign-up
- Verified human, identity undisclosed
- Online poll or vote
- Verified unique human
- Promotion or free trial
- Verified unique human, one per person
- Dating profile
- Verified human, present at profile creation and in conversation
Differentiation
Proof of Human and adjacent approaches
| Approach | Answers | What it adds |
|---|---|---|
| CAPTCHA | Can this visitor complete a challenge that appears human, once? | Evidence of a real human that can persist across a session, without puzzles as the core mechanism. |
| Bot detection | Does this traffic look automated? | A positive claim about the human, and room for legitimate, declared agents. |
| Proof of personhood | Is this a real, unique human? | Presence and control in the current interaction, via Proof of Control. |
| Identity verification (KYC) | Who is this person, legally? | Humanity without identity when identity is not needed. |
API Preview
Request human presence (API Preview)
In the proposed API, an application states what it needs and receives an Actor status it can apply its own policy to. Endpoint and field names are illustrative and will change.
// Proposed API - illustrative only
POST /v1/verifications
{
"requirements": {
"human_presence": true,
"unique_human": true,
"identity": "undisclosed"
}
}
// Conceptual response
{
"actor_type": "human",
"confidence": 0.97,
"personhood": "verified",
"human_presence": "verified",
"identity": { "verified": false, "disclosure": "none" }
}Where it applies
Related use cases
FAQ
Frequently asked questions
What is human verification?
Human verification is any process that gives a service evidence that a real person, rather than software, is behind an interaction. Traditionally it meant CAPTCHA challenges. Proof of Human is designed to establish personhood and presence from multiple independent signals instead of a single puzzle, and to keep identity optional.
Is Proof of Human a CAPTCHA alternative?
It addresses the need CAPTCHAs were built for, but it is not positioned as a better CAPTCHA. A CAPTCHA asks whether a visitor can pass a challenge once. Proof of Human is designed to provide evidence that a real human is present, and, with Proof of Control, that they remain in control throughout the interaction.
How is Proof of Human different from proof of personhood?
Proof of personhood systems focus on establishing that an account belongs to a real, often unique, human. Proof of Human includes that idea but sits inside a wider model that also asks whether the human is present now and whether they are actually controlling the interaction.
Does Proof of Human require my identity or biometrics?
No single signal is required by design, and identity is optional. The privacy principle is to prove what matters without revealing what doesn't: many services only need to know a real human is there, not who they are.
Is Proof of Human available today?
No. Proof of Actor is in development. The API shown on this site is a Developer Preview design and is evolving. You can join the Developer Preview or apply to become a design partner.
- Every primitive returns its result inside the same Actor Attestation, so applications can combine them.
Tell us what you need to verify.
Proof of Actor is being designed with developers and design partners. Your use case shapes the API.