Human-Verified Content Badges - certificate authority for human authorship

[het4rk]

Product Requirements (PRD)

Problem

AI-generated content is flooding the internet. There's no way to prove something was written by a human. Arkora can provide that proof because every account is World ID verified.

Solution

A "Written by a Verified Human" badge/certificate system. Content creators write on Arkora and get a signed certificate (hash of content + nullifier proof). Any website can embed a verification badge that links back to Arkora for proof.

User Stories

1. As a writer, I want to prove my article was written by a verified human, not AI.
2. As a publisher, I want to embed a "Verified Human" badge on articles to build reader trust.
3. As a reader, I want to know if the content I'm reading was authored by a real person.

Features

Content Signing

• User writes/posts on Arkora
• System generates certificate: SHA-256(content) + World ID nullifier proof + timestamp
• Certificate stored onchain (World Chain) or signed by Arkora's key
• User gets a verification URL: https://arkora.app/verify/{hash}

Verification Badge

• Embeddable badge (<script> or <img> with link)
• Shows: "Verified Human Author" + verification date
• Click opens proof page on Arkora showing content hash match

Browser Extension

• Chrome/Firefox extension
• Shows green checkmark on verified content across the web
• Queries Arkora API for content hash matches

Publisher API

• POST /api/verify/content - submit content hash, get verification status
• GET /api/verify/{hash} - check if content was authored by verified human

Revenue

• Free for individual creators (limited to 10 certificates/month)
• Publisher plan ($29/mo): unlimited verifications, API access, custom badge styling
• Enterprise: white-label, bulk verification, SLA

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Technical Requirements (TRD)

New Schema

CREATE TABLE content_certificates (
  id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
  authorHash TEXT NOT NULL REFERENCES human_users(nullifier_hash),
  contentHash TEXT NOT NULL, -- SHA-256 of content
  postId TEXT REFERENCES posts(id), -- optional, if content is an Arkora post
  externalUrl TEXT, -- optional, URL where content is published
  signature TEXT NOT NULL, -- Arkora Ed25519 signature
  createdAt TIMESTAMP DEFAULT NOW(),
  UNIQUE(contentHash)
);

Signing Flow

1. User creates post or requests certificate for external content
2. Server computes SHA-256(normalize(content))
3. Server signs: Ed25519.sign(contentHash + authorNullifier + timestamp, arkoraPrivateKey)
4. Certificate stored in DB, optionally registered onchain
5. Returns verification URL + embed code

Verification Flow

1. Third party submits content or content hash
2. Server looks up certificate by hash
3. Returns: author verification status, timestamp, signature
4. Verifier can check signature against Arkora's public key