@digitaldefiance/eecp-crdt

Encrypted conflict-free replicated data types for collaborative editing. Built on Yjs for deterministic conflict resolution with encrypted content payloads, operation encryption/decryption, and temporal garbage collection.

Features

• Yjs-based text CRDT with encrypted operations
• Insert, delete, and format operations with encryption
• Deterministic conflict resolution for concurrent edits
• Operation encryption with temporal keys
• Temporal garbage collection for expired operations

Installation

npm install @digitaldefiance/eecp-crdt
# or
yarn add @digitaldefiance/eecp-crdt

Key Classes

EncryptedTextCRDT

The main CRDT implementation that wraps Yjs with encryption capabilities.

import { EncryptedTextCRDT } from '@digitaldefiance/eecp-crdt';

const crdt = new EncryptedTextCRDT();

// Insert text at position
crdt.insert(0, 'Hello, world!');

// Delete text
crdt.delete(7, 6); // Removes "world!"

// Get current text
const text = crdt.getText();

OperationEncryptor

Handles encryption and decryption of CRDT operations using temporal keys.

import { OperationEncryptor } from '@digitaldefiance/eecp-crdt';

const encryptor = new OperationEncryptor(temporalKeyManager);

// Encrypt an operation
const encryptedOp = await encryptor.encryptOperation(operation, timeWindow);

// Decrypt an operation
const decryptedOp = await encryptor.decryptOperation(encryptedOp);

CRDTSyncEngine

Manages synchronization of CRDT state between participants.

import { CRDTSyncEngine } from '@digitaldefiance/eecp-crdt';

const syncEngine = new CRDTSyncEngine(crdt);

// Apply remote operation
syncEngine.applyRemoteOperation(encryptedOperation);

// Get local operations to send
const localOps = syncEngine.getLocalOperations();

TemporalGarbageCollector

Automatically removes expired operations based on temporal key lifecycle.

import { TemporalGarbageCollector } from '@digitaldefiance/eecp-crdt';

const gc = new TemporalGarbageCollector(crdt, keyManager);

// Start automatic cleanup
gc.start();

// Manually trigger cleanup
await gc.collectExpiredOperations();

// Stop cleanup
gc.stop();

Usage Example

import {
  EncryptedTextCRDT,
  OperationEncryptor,
  CRDTSyncEngine,
} from '@digitaldefiance/eecp-crdt';
import { TemporalKeyManager } from '@digitaldefiance/eecp-crypto';

// Initialize components
const keyManager = new TemporalKeyManager(/* ... */);
const crdt = new EncryptedTextCRDT();
const encryptor = new OperationEncryptor(keyManager);
const syncEngine = new CRDTSyncEngine(crdt);

// Local edit
crdt.insert(0, 'Hello');

// Get and encrypt local operations
const localOps = syncEngine.getLocalOperations();
const encryptedOps = await Promise.all(
  localOps.map(op => encryptor.encryptOperation(op, currentTimeWindow))
);

// Send encryptedOps to other participants...

// Receive and apply remote operations
const remoteEncryptedOp = /* ... received from network ... */;
const decryptedOp = await encryptor.decryptOperation(remoteEncryptedOp);
syncEngine.applyRemoteOperation(decryptedOp);

// Get current text
console.log(crdt.getText());

Testing

The package includes 50+ tests covering:

• CRDT operations (insert, delete, format)
• Concurrent editing scenarios
• Conflict resolution
• Operation encryption/decryption
• Garbage collection

Run tests:

npm test
# or
yarn test

Technology Stack

• TypeScript - Type-safe implementation
• Yjs - CRDT foundation for conflict resolution
• CRDT - Conflict-free replicated data types
• Encryption - Temporal key-based operation encryption

Related Packages

• @digitaldefiance/eecp-protocol - Protocol definitions
• @digitaldefiance/eecp-crypto - Cryptographic primitives
• @digitaldefiance/eecp-client - Browser client
• @digitaldefiance/eecp-server - Server implementation

License

MIT