Sealed: Wallet-to-Wallet Messaging with Post-Quantum Privacy on Algorand
The Metadata Problem in Messaging
The promise of end-to-end encryption in messaging apps has a well-documented limitation: even when message content is protected, the metadata—who communicates with whom, when, and how often—remains exposed to the service provider. Sealed, a new messenger built on Algorand, addresses this by removing the service provider from the equation entirely.
How Sealed Works
In Sealed, your identity is your Algorand wallet address. When you compose a message, your device encrypts it locally using the recipient’s wallet address. The encrypted payload is then submitted as a transaction to a Sealed smart contract on Algorand. Smart contracts are programs stored on the blockchain that execute automatically when certain conditions are met—in this case, storing and retrieving encrypted messages. To receive messages, your device scans the chain for encrypted blobs that match your unique recipient tag—a hash derived from your scan key—and decrypts only those intended for you.
This serverless architecture means no central entity ever handles your plaintext messages or maintains your contact graph. According to the project’s documentation, not even Sealed can read your messages or see who you’re communicating with.
Post-Quantum Security and Privacy Layers
Sealed’s encryption combines classical (X25519) and post-quantum (ML-KEM-512) cryptography, following NIST standards, with each message using a unique ephemeral keypair for forward secrecy. Messages are padded to a fixed 1KB size to prevent metadata leakage through size analysis.
For blockchain interactions, Sealed employs Oblivious HTTP (OHTTP), which obscures your IP address from Algorand’s RPC endpoints. When your device communicates with the network to send or retrieve messages, the RPC provider processes the request without seeing your origin IP, adding a critical privacy layer.
Simplified Usage with Credits
Because each message is a blockchain transaction, messaging incurs fees. Sealed abstracts this complexity with a credit system: users deposit ALGO into a credit smart contract (10 ALGO = 500 credits, good for 500 messages), and the app manages the blockchain fees transparently.
Development Status and Community Engagement
Sealed’s GitHub repository shows an initial public release on June 18, 2026. The project has submitted an xGov proposal (3534141276) to the Algorand community, requesting 400,000 ALGO to support its development. According to the proposal, Sealed is a decentralized, post-quantum communication infrastructure built on Algorand that enables users to exchange encrypted messages without relying on centralized servers, phone numbers, emails, or traditional identity systems.
While the project’s website describes Sealed as a multi-chain messenger, the current documentation and codebase focus exclusively on Algorand, with no additional chains documented.
Source
- Sealed
- Sealed Docs
- Sealed GitHub
- xGov Proposal 3534141276
- Sealed - Fully Anonymous Multi-Chain Messenger
- Blockchain interaction | Sealed Docs
- Credits | Sealed Docs
- Messaging | Sealed Docs
- Sealed - Decentralized Post-Quantum Communication - xGov Proposal 3534141276 - Page 2 - Governance Discussions - Algoran
- Sealed - Fully Anonymous Multi-Chain Messenger
Source: editorial://brief/7616eb02-d77d-4981-bc92-9c72798e685e