What is BlindKeep?
BlindKeep is an encrypted personal vault. You store files, passwords, and secrets — all encrypted in your browser before anything leaves your device. We never see your data.
What does "zero knowledge" mean?
It means BlindKeep cannot read your data. Your master key is derived from your password on your device using Argon2id. We only receive an authentication key (a separate derivation) — never the encryption key. Even if our servers were seized, your data is indecipherable.
What encryption does BlindKeep use?
- XChaCha20-Poly1305 — authenticated symmetric encryption for all items (256-bit keys, 24-byte nonces)
- Argon2id — memory-hard password hashing for key derivation
- HKDF-SHA256 — deterministic subkey generation (auth key, encryption key, wrapping key)
- X25519 — elliptic-curve Diffie-Hellman for grant key exchange
Each item gets its own random key, double-wrapped: the item is encrypted with its key, and the key is encrypted with your master-derived encryption key.
Is BlindKeep post-quantum safe?
Your stored data: yes. BlindKeep uses XChaCha20-Poly1305 with 256-bit keys. Grover's algorithm halves the effective key strength to 128 bits — still considered secure by NIST.
Sharing and key exchange: not yet. Grant sharing uses X25519 (Curve25519 ECDH), which is vulnerable to Shor's algorithm on a sufficiently large quantum computer. No such computer exists today.
What this means in practice:
- Data at rest in your vault is quantum-resistant right now
- A "harvest now, decrypt later" attacker who captures your encrypted blobs gains nothing
- We are tracking NIST post-quantum standards and will migrate key exchange to ML-KEM when browser support is production-ready
Can BlindKeep employees read my data?
No. Your encryption key never leaves your device. We store only encrypted blobs and an authentication key hash. There is no backdoor, admin panel, or key escrow that would let anyone at BlindKeep decrypt your data.
What are "drops"?
Drops are anonymous, encrypted file shares. No account needed. You upload a file, it's encrypted in your browser, and you get a pickup link plus a 12-word passphrase. The file auto-deletes after 60 minutes.
How does the digital will work?
You name an heir and select which vault items they should inherit. BlindKeep wraps your item keys so only the heir can decrypt them — and only after the dead man's switch triggers. The switch checks in with you on a schedule you set. Miss enough check-ins and the will activates, emailing your heir a secure decryption link.
How does sharing (grants) work?
You share a vault item by creating a grant. The item key is encrypted for the recipient using X25519 key exchange (if they have an account) or a link-secret embedded in the URL fragment (if they don't). You can set view limits, expiry dates, IP restrictions, and revoke access at any time. The server never sees the decryption key.
How much does it cost?
BlindKeep uses GB·year pricing — you pay for the storage you use over time.
- Drops are free — no account needed
- Free tier included — enough for thousands of text secrets
- €5 per GB·year — pay as you go, no subscriptions
- €25 per 10 GB·years — 50% volume discount
Where is my data stored?
Encrypted blobs are stored in European data centres (Scaleway, France). The server runs in the EU. Your data never leaves Europe — and even if it did, it's encrypted with keys only you hold.
What if I forget my password?
If you set up a recovery key during registration, you can use it to regain access to your vault. Without a recovery key or a registered passkey with PRF, a forgotten password means your data is permanently inaccessible — that's the trade-off of true zero-knowledge encryption.