Private Payments. No Servers.
No Surveillance.

Sand Cat is an open-source, quantum-secure Bitcoin messenger that lets you request or send Bitcoin payments using encrypted QR codes. No identity, phone number, wallet address, or internet connection is required.

We believe financial freedom is a human right — and that Bitcoin, like cash, should be usable without compromising your privacy. Sand Cat ensures your right to transact securely, even in the face of censorship, surveillance, or authoritarian overreach.

  • Built with post-quantum encryption

  • Works peer-to-peer — no central server

  • Supports offline payment requests

  • Leaves no digital footprint

Secure your Bitcoin transactions and live on a Bitcoin standard with the same privacy that cash provides.

Private Payments. No Servers.
No Surveillance.

Sand Cat is an open-source, quantum-secure Bitcoin messenger that lets you request or send Bitcoin payments using encrypted QR codes. No identity, phone number, wallet address, or internet connection is required.

We believe financial freedom is a human right — and that Bitcoin, like cash, should be usable without compromising your privacy. Sand Cat ensures your right to transact securely, even in the face of censorship, surveillance, or authoritarian overreach.

Secure Bitcoin Requests via Encrypted QR Codes

  1. Generate a Payment Request
    Sand Cat creates a fresh Bitcoin address and BIP-21 payment link with amount, label, and memo — then encrypts it using Kyber (quantum-safe encryption) and signs it using Dilithium (quantum-safe authentication).

  2. Send with a QR Code
    The entire encrypted payload is encoded as a QR code. You can share it screen-to-screen, print it, or send it however you want — the data is useless to anyone but the recipient.

  3. Scan and Decrypt
    The recipient scans the QR code using Sand Cat. Only they can decrypt it with their private key, verifying the authenticity and viewing the payment details securely.

  4. Pay in Total Privacy
    No address reuse. No metadata. No notification tokens. Just Bitcoin — sent the way it was meant to be: peer to peer, person to person, without permission.

© 2025 Sand Cat, Sand Cat App