BlockStar Cypher
A New Standard for Private, Decentralized Communication
End-to-end encrypted messaging with wallet-derived keys. Own your identity with NFT usernames and communicate securely across all your devices — no central authority, no data harvesting, no compromises.
on every message
on-chain forever
no intermediary
from your messages
What is BlockStar Cypher?
A complete, privacy-first messaging platform where you — not a corporation — own your identity and your conversations.
BlockStar Cypher is a next-generation communication platform that combines the convenience of modern messaging apps with the security and ownership guarantees of blockchain technology. Every message sent through BlockStar Cypher is encrypted using keys derived directly from the user's blockchain wallet — meaning no third party, including BlockStar itself, can ever access the content of your conversations.
Unlike traditional messaging platforms that require an email address, phone number, or accept their terms in exchange for your data, BlockStar Cypher asks only one thing: connect your wallet. That wallet becomes your identity, your encryption key, and your authentication all at once — no passwords, no email verification, no data collection.
"Your keys, your messages. Your wallet, your identity. Your data, your choice — always."
The platform is available across web browsers, iOS, Android, and desktop operating systems. An offline Bluetooth mesh networking mode ensures that users can continue to communicate even when internet connectivity is unavailable.
The Broken State of Digital Privacy
Today's messaging apps ask you to trust them with your most private conversations. That trust has repeatedly been broken.
🏢 Centralized Control
Your username is rented from a corporation. They can ban you, delete your account, or hand over your data to governments — at any time, for any reason.
📊 Data Harvesting
Even "encrypted" apps often collect your metadata — who you talk to, when, how often, and from where. This behavioral data is extraordinarily valuable and frequently sold or breached.
🔓 Single Points of Failure
Centralized servers are prime targets for hackers. A single breach can expose millions of users' messages, contacts, and account information.
📵 Connectivity Gaps
Messaging apps stop working the moment internet access is cut — during disasters, in remote areas, at large events, or when networks are deliberately shut down.
The fundamental issue is that current messaging platforms are built on a model of borrowed identity and trusted intermediaries. You borrow your username from a company, and you trust that company to keep your messages private. Both of these assumptions carry real risk.
BlockStar Cypher was built from the ground up to eliminate these risks entirely by removing the central authority from the equation.
Decentralized, Encrypted, Yours
BlockStar Cypher replaces the central authority model with a system where you are always in control.
The core innovation of BlockStar Cypher is tying every aspect of communication directly to the user's blockchain wallet. Since blockchain wallets are cryptographically secured and user-controlled, this approach gives each user:
Wallet-Derived Encryption Keys
Your wallet's cryptographic signature generates unique encryption keys each time you log in. These keys exist only on your device and are used to encrypt and decrypt all your messages. Nobody else possesses these keys — not even BlockStar.
Blockchain-Based Identity
Your username is an NFT on the blockchain. It cannot be revoked, censored, or taken away. It is yours as long as you hold it in your wallet — and it can be transferred or sold like any digital asset.
Open, Interoperable Platform
BlockStar Cypher is built on open standards. Any EVM-compatible wallet can connect. The platform is available on all major devices and operating systems with no vendor lock-in.
Your Identity, On-Chain
On BlockStar Cypher, your identity is not rented — it is owned. Your @username is a Non-Fungible Token (NFT) that lives in your wallet.
Through BlockStar Domains, users can mint a human-readable username such as @alice or @satoshi as an NFT on BlockStar Mainnet. This NFT serves as their identity across the entire BlockStar ecosystem, including Cypher.
True Ownership
The NFT is stored in your wallet. Whoever controls the wallet controls the identity — no company in the middle.
Permanent
Once minted, your username exists permanently on the blockchain. It cannot be deleted, suspended, or modified by anyone other than you.
Transferable
NFT usernames can be transferred, sold, or gifted like any other digital asset — creating a genuine market for premium usernames.
Cross-App Identity
Your BlockStar Domain works across all BlockStar applications — one identity for everything you do in the ecosystem.
Users without a BlockStar Domain NFT can still use BlockStar Cypher. Their wallet address is used as a unique identifier, displayed in a shortened human-readable format. They can be found and messaged by anyone who knows their wallet address.
Messages That Only You Can Read
Every conversation on BlockStar Cypher is protected by end-to-end encryption. From the moment you hit send, your message is encrypted and unreadable to everyone except your intended recipient.
The encryption is built on a wallet-derived key system. When you connect your wallet and sign the authentication message, a unique set of cryptographic keys is generated from your wallet's signature. These keys are used to encrypt every message before it leaves your device, and only the recipient — who has their own wallet-derived keys — can decrypt them on their end.
"Encrypted messages travel through BlockStar's servers like sealed envelopes — the postal service can move them, but can never open them."
What You Can Send
BlockStar Cypher supports a rich range of message types, all protected by the same encryption:
Additional Messaging Features
Crystal-Clear, Encrypted Calls
Make voice and video calls that are just as private as your messages — peer-to-peer, encrypted, and with no call recordings on any server.
Calls on BlockStar Cypher use WebRTC — the same peer-to-peer technology that powers leading communication platforms. Where possible, call data travels directly between you and the person you are calling without any server in the middle. This is not only more private but also results in lower latency and better call quality.
📞 One-to-One Calls
Start an audio or video call from any direct message conversation. The call connects directly between the two parties whenever network conditions allow.
👥 Group Calls
Start a group call from any group conversation. All members receive a call notification and can join simultaneously for a shared audio or video session.
All call media is encrypted using DTLS-SRTP, the industry standard for real-time communication security. No call audio or video is ever recorded or stored on BlockStar's servers. If a network firewall prevents direct connections, calls gracefully fall back through a relay server — still encrypted.
Share Files With Total Privacy
Every file shared on BlockStar Cypher — images, documents, audio, video — is encrypted before it ever leaves your device.
When you share a file, BlockStar Cypher generates a unique encryption key for that specific file, encrypts it on your device, and only then uploads it to storage. The encrypted file on the server is completely meaningless without the key, which only the recipient can obtain through the encrypted messaging channel.
📁 Supported File Types
Automatic thumbnail generation lets recipients preview images and videos without downloading the full file first. Voice notes include a waveform visualisation and a playback timer for a seamless audio experience.
Encrypted Group Conversations
Create private group conversations for teams, communities, or DAOs — all encrypted so only members can read the messages.
Group chats on BlockStar Cypher use a shared group encryption key that is distributed securely to all members when they join. This means every message in a group is encrypted with a key that only current members possess.
When a member leaves or is removed from a group, the group encryption key is automatically rotated. This ensures that former members cannot decrypt messages sent after their departure — a security property known as forward secrecy.
Your Conversations, Everywhere
Access your full message history on any device without any complex setup. Connect your wallet, and everything is there instantly.
Most competing secure messaging platforms either tie you to a single device or require a QR-code pairing process to add new devices. BlockStar Cypher takes a different approach: because your encryption keys are derived deterministically from your wallet signature, any device where you sign in with the same wallet automatically generates identical keys — and can therefore decrypt your entire message history.
Messages are stored in their encrypted form. When you open the app on a new device and sign in, your device downloads the encrypted messages and decrypts them locally. The process is automatic, fast, and completely transparent to the user.
Communicate Without the Internet
BlockStar Cypher's mesh networking mode enables secure communication even when there is no internet connection whatsoever.
The mobile apps for iOS and Android include a mesh networking mode that uses Bluetooth Low Energy and WiFi Direct to connect nearby BlockStar Cypher users into a local mesh network. Messages hop from device to device — like a relay race — until they reach their destination, even if the sender and recipient are not in direct range of each other.
📡 How the Mesh Works
Ideal Use Cases
Stay Informed, Stay Private
Receive instant notifications for new messages — even when the app is not open — while keeping full control over what information is revealed.
BlockStar Cypher uses push notifications to alert you when new messages arrive. On mobile, this works via iOS and Android native push services. On the web, it uses the standard Web Push API with Service Workers.
A key feature is the privacy-first notification preview setting. You can choose to show the sender's name and message content in the notification, or you can choose to receive only a silent alert with no preview — protecting your messages even on your lock screen.
🔔 Notification Modes
- → Full preview (name + message)
- → Sender only (no message content)
- → Silent alert only
- → Off entirely
🔕 Granular Controls
- → Mute specific conversations
- → Set Do Not Disturb hours
- → Custom sounds per conversation
- → Per-group notification settings
Connecting Across Blockchains
BlockStar Cypher is natively built on BlockStar Mainnet but welcomes users from across the EVM ecosystem.
The platform uses standard EVM-compatible wallet authentication. This means that users with wallets on Ethereum, Polygon, BNB Chain, and any other EVM-compatible network can connect to BlockStar Cypher and start messaging. NFT username support is specific to BlockStar Mainnet, but wallet-based identity works universally.
⛓️ BlockStar Mainnet — The Native Chain
BlockStar Mainnet is the home chain of Cypher. It hosts the BlockStar Domains NFT username contracts and is the network where the BST token operates. Users on BlockStar Mainnet get the full feature set, including NFT usernames.
The roadmap includes cross-chain identity bridges that will allow users to carry their BlockStar Domain username across multiple chains, and bridges that will enable messaging across blockchain ecosystems — bringing truly universal decentralized communication closer to reality.
How BlockStar Cypher Compares
A straightforward comparison of BlockStar Cypher against traditional and other encrypted messaging platforms.
| Feature | BlockStar Cypher | Traditional Apps | Other Encrypted Apps |
|---|---|---|---|
| End-to-End Encryption | ✓ Wallet-derived keys | ✗ Server can read | ✓ Yes |
| Own Your Identity | ✓ NFT username | ✗ Company owns it | ✗ Phone number based |
| No Phone Number Required | ✓ Wallet only | ✗ Required | ✗ Usually required |
| Multi-Device Sync | ✓ Automatic via wallet | ✓ Yes | ~ QR pairing required |
| Offline Messaging (Mesh) | ✓ Bluetooth + WiFi | ✗ No | ✗ No |
| Group Encrypted Chats | ✓ Full encryption | ✗ Often not E2E | ✓ Yes |
| Encrypted File Sharing | ✓ AES-256 per file | ✗ Unencrypted storage | ~ Varies |
| Encrypted Calls | ✓ DTLS-SRTP | ✗ Often unencrypted | ✓ Yes |
| Transferable Identity | ✓ NFT, sell/transfer | ✗ No | ✗ No |
| No Data Harvesting | ✓ Zero readable data | ✗ Business model | ~ Metadata may be collected |
Privacy by Design
Privacy is not a feature added to BlockStar Cypher — it is the foundation upon which the entire platform is built.
The platform operates on a simple principle: BlockStar's servers should never be able to read your messages, know who you are talking to, or track your behaviour. Every design decision flows from this principle.
Zero-Knowledge Architecture
The server stores only encrypted blobs. It has no knowledge of message content, attachments, or the meaning of any data it holds.
No Personal Information Required
Sign-up requires only a wallet connection. No name, no email, no phone number is ever collected or stored.
No Advertising, No Data Sales
BlockStar Cypher does not sell user data and does not serve advertising. The platform has no business model that depends on knowing what you talk about.
User-Controlled Privacy Settings
Each user can independently control their online status visibility, read receipt behaviour, notification previews, and who can contact them.
What's Coming Next
BlockStar Cypher is a living platform. Here is a high-level view of planned features and improvements.
Cross-Chain Identity Bridge
In DevelopmentAllow BlockStar Domain usernames to work across Ethereum, Polygon, and other EVM chains. One identity everywhere.
Disappearing Messages
PlannedSet messages to automatically delete after a configurable time period — 24 hours, 7 days, 30 days, or custom.
DAO & Community Channels
PlannedBroadcast channels and DAO governance message boards — encrypted, NFT-gated spaces for Web3 communities.
Expanded Mesh Range
PlannedImproved mesh networking with longer range, more efficient relay protocols, and support for larger offline networks.
A New Era of Private Communication
BlockStar Cypher represents a fundamental shift in how we think about digital communication. By combining the security of end-to-end encryption, the ownership guarantees of blockchain technology, and the convenience of a modern messaging app, it delivers something genuinely new: a platform where users are truly in control.
No more renting your identity from a corporation. No more trusting that a company will protect your conversations. No more losing your account when they decide to ban you. On BlockStar Cypher, your wallet is your identity, your keys encrypt your messages, and nobody — not even us — can take any of that away from you.
"The future of communication is private, decentralized, and user-owned. BlockStar Cypher is that future, available today."
We are committed to continuous improvement, user privacy, and open standards. BlockStar Cypher is more than a messaging app — it is a statement about what the internet can and should be.
© BlockStar Cypher. All rights reserved.
This document is a feature overview white paper. It is not a financial or investment document.