Immutable Source of Truth for Document Identity

The IntegraDocumentRegistry is the foundational smart contract that records every document registration in the Integra ecosystem. Think of it as a global notary that never sleeps, never loses records, and never requires trust—only verification.

When you register a document with Integra, its cryptographic identity is permanently recorded in the Document Registry. This creates an immutable timestamp proving exactly when your document existed and what its contents were at that moment. The registry doesn't store your document—it stores the mathematical proof of your document.

Chain-Agnostic Document Identity

The Document Registry is deployed across 20+ EVM-compatible blockchains, but your document's identity—the integraHash—remains consistent everywhere. Register once, verify anywhere. Whether your counterparty prefers Ethereum, Polygon, Arbitrum, or Base, they can verify your document using the same integraHash.

This multi-chain architecture provides redundancy, accessibility, and flexibility:

• Redundancy: Document proof exists on multiple independent networks
• Accessibility: Users choose their preferred chain based on cost and speed
• Flexibility: Future chains can be added without changing existing registrations

What the Registry Stores

For each registered document, the registry maintains:

Field	Purpose
integraHash	Unique document identifier
documentHash	SHA-256 hash of document content
owner	Blockchain address of document owner
tokenizer	Authorized token contract (if any)
timestamp	Block timestamp of registration
resolvers	Attached service contracts

The registry stores only cryptographic proofs and references—never document content. Your sensitive information never touches the blockchain.

The Hash Storage Model

The Document Registry implements a privacy-preserving architecture where only cryptographic hashes are stored on-chain. This achieves what we call "public proof of private information"—anyone can verify a document's authenticity without the blockchain ever containing the document itself.

How it works:

1. Client-side hashing: The SHA-256 hash of your document is computed locally, in your browser or application. Your document never leaves your control.
2. On-chain registration: Only the hash and metadata are submitted to the blockchain. The registry stores this cryptographic fingerprint permanently.
3. Verification by comparison: Anyone with access to the document can independently compute its hash and compare to the registry. If hashes match, the document is verified.

Privacy by Design

Documents contain sensitive information—personal details, financial terms, proprietary arrangements. Storing documents on blockchain would be a privacy violation. Storing documents on IPFS would expose them publicly.

The Document Registry solves this fundamentally:

• Document content: Stays with owner, encrypted, private
• Document proof: Lives on blockchain, public, verifiable
• Verification: Requires the document—ensures authorized access

This architecture satisfies the strictest privacy requirements (GDPR, HIPAA, enterprise confidentiality) while enabling instant public verification.

Immutability Guarantees

Once a document is registered, its core identity cannot be modified:

• integraHash: Permanent and unchangeable
• documentHash: Permanent and unchangeable
• timestamp: Permanent block timestamp
• ownership: Transferable through defined processes only

This immutability is essential for legal standing. Courts, regulators, and auditors need proof that hasn't been tampered with. The Document Registry provides exactly that.