Privacy Policy
GalleryMint — Proof-of-Presence Digital Collection
Last updated: May 16, 2026
1. Overview
GalleryMint ("we," "our," or "the app") is a proof-of-presence digital collection application. We are committed to protecting your privacy. This policy explains what data we collect, how we use it, and your rights.
2. Data We Collect
Data stored only on your device (never sent to our servers):
- Wallet seed phrase — Your 12-word recovery phrase is generated and stored exclusively on your device using secure encrypted storage. We never have access to it.
- Display name and photo — Optional personalization stored locally on your device only.
- Collected art pieces — Your collection is cached locally for offline viewing.
Data sent to our servers when you collect an art piece:
- GPS coordinates — Used to verify you are physically at the artwork. Coordinates are recorded in the on-chain NFT commitment as proof of presence. We do not track your location at any other time.
- NFC card data — Cryptographic signature from the NFC card, used to verify physical presence. Contains no personal information.
- Wallet address — Your Bitcoin Cash wallet address, used to send you the edition NFT. This is a public blockchain address, not tied to your identity.
Data we do NOT collect:
- Your name, email, or phone number (unless you create an artist account)
- Your location when you're not actively collecting an art piece
- Your contacts, photos, or browsing history
- Your seed phrase or private keys — ever
3. How We Use Your Data
- Art piece verification — GPS and NFC data are used solely to verify you were physically present at an artwork before minting an edition NFT.
- NFT minting — Your wallet address is used to send the CashToken NFT to your wallet.
- On-chain recording — Location coordinates and timestamp are embedded in the NFT commitment on the Bitcoin Cash blockchain. This data is public and permanent by design — it IS the proof of presence.
4. Blockchain Data
GalleryMint editions are CashToken NFTs on the Bitcoin Cash blockchain. Once minted, the following data is permanently and publicly recorded on-chain:
- A hash of the artwork ID
- GPS coordinates (latitude/longitude) at time of collection
- Timestamp
- NFC card identifier and counter
- Your wallet address (as the NFT recipient)
This data cannot be deleted or modified. This is intentional — it provides the cryptographic proof of presence that makes GalleryMint valuable.
5. Third-Party Services
- Bitcoin Cash network — NFT transactions are broadcast to the public blockchain.
- Electrum servers — Used to broadcast transactions and query blockchain data.
- Brevo — Used for transactional emails (artist account verification only).
- Stripe — Used for payment processing (artist card purchases only).
- Umami Analytics — Privacy-focused, cookie-free website analytics on gallerymint.io. No personal data is collected.
6. Data Security
- Your wallet seed phrase is stored in encrypted secure storage on your device.
- NFC card authentication uses AES-128 encryption with rolling counters to prevent replay attacks.
- All API communications use HTTPS/TLS encryption.
- Server data is stored in a secured MySQL database with access controls.
7. Your Rights
- Your editions are yours — They are NFTs in your self-custodial wallet. You can send, trade, or hold them. We cannot take them from you.
- Delete your account — You can delete your wallet from the app at any time via Settings. This removes all local data from your device.
- On-chain data — Blockchain data is permanent by design and cannot be deleted. This is a feature, not a limitation.
8. Children's Privacy
GalleryMint is not directed at children under 13. We do not knowingly collect personal information from children.
9. Artist Accounts
If you create an artist account to sell GalleryMint cards, we additionally collect your email address, business name, and phone number for account management and communication purposes.
10. Changes to This Policy
We may update this privacy policy from time to time. The latest version will always be available at gallerymint.io/privacy.
11. Contact
For privacy questions or concerns, contact us at:
privacy@gallerymint.io