Flash Infrastructure

How Flash Works Under the Hood

Flash combines open-source technologies to create a seamless financial application. This page explains the technical infrastructure powering Flash.

Core Technology Stack

1. Bitcoin Core Integration

Flash connects to the Bitcoin network through:

Bitcoin Core nodes for blockchain validation
Electrum Server for efficient data access
Address indexing for fast balance lookups

This provides on-chain Bitcoin functionality with self-custody withdrawals, transaction verification, and deposit detection.

2. Lightning Network Implementation

Flash uses LND for Lightning functionality:

LND nodes provide core Lightning capabilities
Custom middleware manages channel liquidity

Enabling instant payments, sub-cent micropayments, and cross-border transactions.

3. NOSTR Protocol Integration

Flash incorporates NOSTR via:

Multiple relay connections for censorship resistance
Client-side key management for identity control
End-to-end encryption for private messages

Powering direct messaging, group chats, and business communication.

4. eCash System

Flash implements a chaumian eCash system offering:

Full transaction privacy
Off-chain scaling
Offline payment capabilities

5. BTCPay Server Integration

Flash leverages BTCPay Server for:

Flash Cards payment processing
Rewards system management
Merchant services infrastructure

System Architecture

Flash’s architecture is designed for reliability, scalability, and security with these key components:

Server Components

API Layer, Authentication Service, Lightning Service
Bitcoin Service, NOSTR Relay, eCash Mint
Database Cluster, Analytics Engine, BTCPay Server

Client Components

Secure Key Storage, Local Database, NOSTR Client
Backup Systems, Payment Logic

Security Model

Flash employs multiple security layers:

HSM-protected nodes for Lightning and Bitcoin keys
Multi-signature wallets for cold storage reserves
Regular security audits and encrypted databases
Rate limiting and anomaly detection systems

Open Source Components

Flash builds upon and contributes to:

LND - Lightning Network implementation
Galoy - Bitcoin banking infrastructure
NOSTR - Decentralized social protocol
Breez SDK - Lightning SDK components
Cashu - eCash implementation
BTCPay Server - Self-hosted payment processor

Developer Resources

Flash is committed to open-source development and welcomes community contributions.