Frequently Asked Questions

BlindPost is a free, end-to-end encrypted messaging application built on the Blind Post protocol. It allows you to communicate privately without requiring a phone number, email, or any personal information. Your Ed25519 cryptographic key pair is your identity.

Every message is encrypted on your device before it is sent. BlindPost uses X25519 for key exchange and AES-256-GCM for symmetric encryption. Messages are transmitted as encrypted blobs through relay servers that cannot read, identify, or associate messages with any user. This is a zero-knowledge architecture.

The Blind Post protocol is the messaging framework used by BlindPost. It treats relay servers like a "blind post office" — they receive, store, and forward encrypted message blobs without any knowledge of the content, sender, or recipient. Think of it as dropping a sealed, anonymous letter into a mailbox.

No. BlindPost does not require any personal information. When you first open the app, an Ed25519 key pair is generated locally on your device. Your public key is your identity. No phone number, email, or password is needed.

No. Messages are encrypted on your device before they leave it. Our relay servers only handle encrypted blobs that they cannot decrypt. Even if our servers were compromised, your message content would remain completely private.

If you have backed up your mnemonic phrase, you can restore your identity on a new device using the backup file (.mca) and mnemonic. If you have not backed up your mnemonic phrase and lose your private key, your identity is permanently lost and cannot be recovered — not even by us. We strongly recommend backing up your mnemonic phrase when you first create your account.

BlindPost is currently available for Android (APK direct download) and macOS (DMG). iOS and Windows/Linux versions are in development. Stay tuned for updates!

Yes, BlindPost is completely free to use. There are no subscription fees, no ads, and no in-app purchases. We believe private communication is a fundamental right.

Yes. BlindPost supports group chats with end-to-end encryption. All messages in group conversations are encrypted for each member individually, ensuring that only group members can read the messages.

You can add contacts by scanning their public key QR code, or by sharing your QR code for them to scan. This ensures that you are connecting with the right person through cryptographic verification — no central server is involved in the trust process.