Definition
Zero-Knowledge
A design where the service provider cannot access your data because it never holds the keys to decrypt it.
A zero-knowledge service is architected so that even its own operators cannot read your data. Encryption and decryption happen on your device with keys derived from a secret only you hold.
Why it matters: zero-knowledge converts a trust promise into a structural guarantee. If the provider literally cannot decrypt your data, a data incident, a subpoena, or a rogue employee exposes far less. Verify the claim against published audits, not marketing.
Related terms
End-to-End Encryption (E2EE) · Password Manager · Digital Sovereignty