Aphasia

Problem Statement

Aphasia, a decentralized reputation layer that verifies online reviews using verifiable credentials and zero-knowledge proofs. It starts as a Chrome extension, allowing users to instantly see verified reviews and trust scores across any website, sourced from decentralized identity systems and social attestations rather than opaque platforms. Aphasia brings cryptographic verification and AI-powered curation to online reviews, combining Hedera's blockchain infrastructure with advanced AI agents to create a universal layer of trust for the open web.Three-Tier Verification System Level 1 - Email Verification (Off-chain, Free) Basic human verification through email validation. Stops simple bots and spam. Trust Score: 30/100. Level 2 - Social Reputation (Off-chain, Free) OAuth integration with LinkedIn, Twitter/X, and Google. Our reputation scoring algorithm analyzes account age, follower count, and activity patterns to prevent sockpuppets. Trust Score: 60-80/100. Level 3 - Unique Human (On-chain, Verified by Hedera) Biometric verification via Self Protocol using zero-knowledge proofs. Each verification is attested through our VerificationRegistry smart contract on Hedera EVM, with nullifiers stored on-chain to cryptographically guarantee one person equals one account. HCS messages provide an immutable backup. Trust Score: 95/100. On-Chain Review Attestations Reviews from Level 3 verified users are attested using our ReviewAttestation smart contract deployed on Hedera EVM. Each attestation includes:Review ID and product identifier IPFS hash of review content Reviewer's DID (decentralized identifier) Rating and timestamp HCS sequence numberUsers can verify any review with one click, seeing the complete chain of proof: IPFS content → HCS message → Smart contract attestation → Hashscan explorer. AI Recommendation Agent Powered by Hedera Agent Kit, our AI agent understands natural language queries like "What's the best laptop under $1000?" and provides curated recommendations based on:Verified review analysis across all products Trust score weighting (Level 3 reviews weighted higher) Sentiment analysis and review quality Recency and relevance factorsAll agent queries and responses are logged to HCS for transparency and auditability. This creates a decentralized record of AI decision-making. How Users Experience AphasiaInstall Chrome extension (5 seconds) Browse any website - Amazon, Airbnb, eBay, anywhere with reviews See trust scores overlaid automatically on product pages Read verified reviews with clear trust badges (Level 1/2/3) Ask the AI agent anything: "Find me the best wireless earbuds for running" Verify on-chain with one click to see cryptographic proof Write your own reviews and build portable reputation across platformsInnovation & Impact Aphasia represents a paradigm shift in online trust:Hybrid Architecture - Off-chain for scale (Level 1-2), on-chain for truth (Level 3) Progressive Verification - Users choose their trust level, no forced complexity AI + Blockchain Synergy - Verifiable data meets intelligent curation Universal Compatibility - Works on any website via Chrome extension Privacy-Preserving - Zero-knowledge proofs protect user identityWe're not just fighting fake reviews. We're building the infrastructure for verifiable reputation in the age of AI.Landing page: https://inspirational-action-786471.framer.app/

Solution

Technology Stack Frontend (Chrome Extension): React 18 + TypeScript + Vite Background service worker for API calls Chrome Extension Manifest V3Backend API: Node.js + Express + TypeScript PostgreSQL (Neon serverless) + Prisma ORM JWT authentication RESTful API designBlockchain (Hedera): Smart Contracts: Solidity 0.8.24 deployed on Hedera EVM Development: Hardhat 3.0 (using new Solidity test features) Libraries: ethers.js v6 for contract interaction Services: HCS for message submission, Mirror Node API for queriesStorage: IPFS (Pinata) for review content and images PostgreSQL for fast querying and caching Hybrid approach: off-chain for speed, on-chain for proofVerification: Self Protocol for biometric verification (Level 3) OAuth 2.0 for social verification (Level 2) Custom email verification (Level 1)