Technical Architecture

System Architecture Overview

CrypTalk's architecture is built on a hybrid model that combines centralized and decentralized components to maximize both security and usability. The system uses a layered approach with clear separation of concerns between client-side operations and server-side functions.

1. Client-Side Architecture

   1.1 Application Layer

   • Web Client: Progressive Web Application (PWA) built with React and TypeScript

   • Mobile Client: Native applications for iOS (Swift) and Android (Kotlin) with shared cryptographic libraries

   • Desktop Client: Electron-based application sharing core components with the web client

   1.2 Cryptographic Engine

   • Key Management Subsystem

     • Generates and manages ephemeral key pairs

     • Implements Perfect Forward Secrecy through X3DH (Extended Triple Diffie-Hellman) key agreement protocol

     • Securely stores keys in isolated secure enclaves when available

   • Encryption/Decryption Module

     • Implements AES-256-GCM for symmetric encryption

     • Uses ChaCha20-Poly1305 as an alternative cipher for devices with limited AES hardware acceleration

     • Handles message authentication using HMAC-SHA256

   • Zero-Knowledge Proof System

     • Generates proofs for authentication without revealing actual credentials

     • Implements Schnorr signatures for lightweight authentication

   1.3 Local Storage Manager

   • Encrypted Local Database

     • SQLCipher implementation for secure local data storage

     • Automatic encryption/decryption of stored data

     • Configurable ephemeral storage with timed deletion

   • Memory Security

     • Secure memory handling with protection against memory dumps

     • Immediate memory zeroing after use

     • Anti-debugging measures to prevent runtime inspection

   1.4 Network Interface

   • Connection Manager

     • WebSocket secure connections for real-time messaging

     • WebRTC implementation for P2P voice/video connections

     • HTTPS RESTful API for non-real-time operations

   • Transport Security

     • TLS 1.3 with certificate pinning

     • DNS-over-HTTPS for secure name resolution

     • SNI encryption for additional metadata protection

   2. Server-Side Architecture

   2.1 Edge Service Layer

   • Connection Gateway

     • Handles incoming connections and load balancing

     • Implements rate limiting and DDoS protection

     • Performs preliminary request validation

   • Geographic Distribution

     • Global CDN integration for static assets

     • Regional node placement for latency optimization

     • Automatic redirection based on connection quality and load

   2.2 Core Services

   • Message Relay System

     • Encrypted message propagation between clients

     • No message content storage or processing

     • Minimal metadata handling with rapid purging

   • Room Management

     • Ephemeral room creation and destruction

     • Secure room discovery mechanisms

     • Participant management without persistent identifiers

   • Authentication Service

     • Zero-knowledge authentication protocols

     • Challenge-response verification system

     • Session management without permanent identifiers

   2.3 Integrated Services

   • Proxy Network Coordinator

     • Manages the network of rotating proxies

     • Handles entry and exit node selection

     • Implements traffic routing algorithms

   • IPFS/Filecoin Gateway

     • Interfaces with decentralized storage networks

     • Manages content addressing and retrieval

     • Handles payment channels for storage services

   • AI Processing Module

     • Implements privacy-preserving machine learning

     • Local model deployment when possible

     • Federated learning without individual data exposure

   2.4 Infrastructure Layer

   • Containerized Deployment

     • Docker containers for service isolation

     • Kubernetes orchestration for scaling and management

     • Immutable infrastructure patterns for security

   • Monitoring and Security

     • Zero-knowledge monitoring (aggregate metrics only)

     • Real-time security analysis without content inspection

     • Anomaly detection for potential attack patterns

   3. Decentralized Components

   3.1 Distributed Storage Network

   • Integration with Filecoin

     • Smart contract implementation for storage agreements

     • Content-addressable storage system

     • Proof-of-replication verification

   • Data Sharding and Recovery

     • Erasure coding for data redundancy

     • Geographic distribution of shards

     • Threshold recovery schemes

   3.2 Blockchain Components

   • RWA Marketplace Backend

     • Smart contract implementation for marketplace transactions

     • Multi-signature escrow system

     • Atomic swap capabilities for cross-chain assets

   • Payment Channels

     • Lightning Network integration for Bitcoin

     • State channels for Ethereum-based transactions

     • Zero-knowledge proofs for transaction privacy

   3.3 P2P Communication Network

   • Direct Connection Framework

     • WebRTC signaling with end-to-end encryption

     • ICE/STUN/TURN servers for NAT traversal

     • Bandwidth adaptation for varying network conditions

   • Mesh Network Capabilities

     • Optional peer relaying for improved anonymity

     • Local network discovery for offline operation

     • Distributed hash table for peer discovery