The NOSTR Protocol

How NOSTR enables censorship-resistant communication in Flash's Chat feature

What is NOSTR?

NOSTR (Notes and Other Stuff Transmitted by Relays) is an open protocol that powers Flash’s Chat functionality. Designed for censorship-resistant global communication, NOSTR creates a decentralized social network where no single entity controls user data or communications.

Unlike traditional social networks and messaging apps that rely on central servers, NOSTR distributes messages across multiple independent relay servers. This architecture makes it nearly impossible for anyone to silence communication or control the flow of information.

How NOSTR Powers Flash Chat

Flash integrates NOSTR to provide a secure, censorship-resistant chat system that works globally:

Core Chat Features

Direct Messaging: Private conversations between users
Group Chats: Communication among multiple participants
Public Channels: Community discussion spaces
Flash Support Channel: Official support channel for users

Integration Benefits

Cross-Platform Compatibility: Chat with friends using other NOSTR clients
Self-Sovereign Identity: Control your own cryptographic identity
No Central Authority: No company can access or censor your messages
Persistence: Messages remain available even if Flash were to disappear

Technical Architecture

NOSTR employs a simple yet powerful technical design:

Key Components

Public Key Cryptography: Each user has a public/private key pair
Events: Standardized data format for all content (messages, profiles, etc.)
Relays: Servers that store and transmit events between users
Clients: Applications (like Flash) that interact with relays

How It Works

Identity Creation: When you set up Flash Chat, you generate a cryptographic key pair
Message Authoring: Your messages are signed with your private key
Message Publication: Signed messages are published to multiple relays
Message Distribution: Relays share messages with other connected users
Signature Verification: Recipients verify your signature using your public key

Relay Infrastructure

Messages in NOSTR propagate through a network of relay servers:

Multiple Relays: Flash connects to several relays for redundancy
Relay Selection: Users can choose which relays to trust
Relay Publishing: Flash publishes important messages to multiple relays
Message Filtering: Clients can request specific content from relays

Key NOSTR Features in Flash

Flash leverages NOSTR’s capabilities to provide several important features:

Privacy and Security

End-to-End Encryption: Private messages are encrypted
Cryptographic Verification: Ensures message authenticity
User Control: Set your own privacy preferences
No Phone Number Requirement: Use without revealing personal information

Censorship Resistance

No Central Authority: No single entity can silence your voice
Relay Diversity: Multiple paths for message delivery
Client Portability: Access your identity from different apps
Borderless Communication: Works globally without restrictions

Cross-Application Compatibility

Open Standard: Works with any NOSTR-compatible application
Identity Portability: Use your NOSTR identity across platforms
Contact Sharing: Connect with friends on different apps
Ecosystem Access: Participate in the broader NOSTR network

Using NOSTR in Flash

Flash makes NOSTR’s powerful capabilities accessible to everyone:

Getting Started

Open Flash: Download and install the Flash app
Access Chat Tab: Tap the Chat icon in the navigation bar
Create Profile: Set up your NOSTR identity (or import existing keys)
Start Messaging: Connect with friends and join channels

Finding Contacts

Connect with others on NOSTR through Flash:

Scan QR Code: Scan a friend’s NOSTR public key QR code
Search by Key: Enter a NOSTR public key directly
Username Search: Find people by their NOSTR username (if registered)
Join Channels: Discover people in public discussion spaces

Managing Your Identity

Your NOSTR identity in Flash is portable and self-sovereign:

Backup Your Keys: Save your private key securely
Import Existing Keys: Use your existing NOSTR identity in Flash
Multiple Devices: Access your account from different devices
Identity Recovery: Restore your profile using your private key

Zaps: Bitcoin Payments in Chat

A powerful feature of NOSTR in Flash is the ability to send Bitcoin payments directly in chat conversations:

What are Zaps?

Zaps are Bitcoin Lightning Network payments sent within NOSTR:

Micropayments: Send tiny amounts of Bitcoin with messages
Content Support: Tip friends for valuable contributions
Integrated Experience: Payment and messaging in one flow
Cross-platform: Works between different NOSTR clients

Sending Zaps in Flash

Open a chat conversation
Tap the lightning bolt icon
Enter the amount to send
Add an optional note
Confirm the payment

Receiving Zaps

When someone sends you a Zap in Flash:

You’ll see the Zap in your chat conversation
The Bitcoin is instantly added to your Flash wallet
A notification appears if your app is in the background
The transaction appears in your payment history

NOSTR Beyond Chat

While Flash currently uses NOSTR primarily for chat, the protocol enables much more:

Current NOSTR Capabilities

Short-form Content: Twitter-like posts and replies
Long-form Content: Blog-style articles and newsletters
Media Sharing: Images, videos, and other attachments
Marketplace Functionality: Buy and sell with Bitcoin

Future Potential in Flash

Flash plans to expand NOSTR integration:

Enhanced Business Communication: Advanced tools for merchants
Content Discovery: Find Bitcoin-focused content and creators
Community Building: Create and join interest-based groups
Identity Verification: Optional proof of identity for businesses

The NOSTR Ecosystem

Flash’s Chat is part of a growing ecosystem of NOSTR applications:

Popular NOSTR Clients

Damus: iOS-focused NOSTR client
Amethyst: Android NOSTR experience
Snort: Web-based NOSTR platform
Primal: Feature-rich web and mobile client

Key NOSTR Projects

NIP Development: NOSTR Improvement Proposals defining standards
Relay Software: Various implementations of relay servers
Developer Tools: Libraries and SDKs for building on NOSTR
User Directories: Ways to discover people on the network

Technical Specifications

For developers interested in NOSTR’s technical details:

Event Types

NOSTR uses different event types for various content:

Kind 1: Short text notes (posts)
Kind 4: Encrypted direct messages
Kind 3: Contact lists
Kind 0: Metadata (profiles)
Kind 9735: Zap receipts for payments

NIPs (NOSTR Improvement Proposals)

The protocol evolves through NIPs:

NIP-01: Basic protocol specification
NIP-04: Encrypted direct messages
NIP-05: Mapping identifiers to keys (usernames)
NIP-57: Zap functionality for Lightning payments

NOSTR URIs

Flash supports standard NOSTR addressing:

nostr:npub…: Link to a user profile
nostr:note…: Link to a specific message
nostr:nevent…: Link to any event type

Resources

By integrating NOSTR, Flash provides users with communication capabilities that are as censorship-resistant and decentralized as Bitcoin itself. This alignment of technologies creates a platform where both money and messages flow freely, outside the control of any central authority.