Security
Vault-opening keys stay on your device
Encryption and decryption stay on user devices. The relay stores ciphertext and an authentication-key verifier, but not master passwords or vault-opening keys. A database leak can still enable offline password guessing.
Zero knowledge
Keys stay with people, not the server
AES-256-GCM
Item encryption
Each vault item is authenticated ciphertext. Tampering causes decryption to fail.
ECDH P-256
Member key exchange
Group keys are wrapped for each member with ECIES — an ephemeral ECDH P-256 exchange, HKDF-SHA256 key derivation, and AES-256-GCM — so private keys are never exposed.
Argon2id
Local key derivation
The master password derives an unlock key on the device and is never sent to Credseal.
Signed events
Tamper-evident audit
Device signatures, hash chaining, and server anchors make later alteration detectable.
Least privilege
Role-based access
Four roles separate ownership, administration, editing, and read-only use.
Honest limits
No impossible promises
We cannot reset a forgotten master password; without your recovery key the vault cannot be recovered, and previously copied plaintext cannot be remotely erased.
Verify the design, including its limits.
Our security model states what the server sees, what devices hold, and what revocation can—and cannot—do.
Read the FAQ