# What is End-to-end encryption?

> Encryption applied on the sender's device and removed only on the recipient's, leaving intermediaries unable to read the content.

Last reviewed: 2026-09-01

## End-to-end encryption

Category: Cryptography

Also called: E2EE

Canonical page: https://moolkey.com/glossary/end-to-end-encryption

End-to-end encryption encrypts data on the sending device and decrypts it only on the receiving device. The service provider, the network, and any server in between handle ciphertext they cannot read. The provider transports your data without being able to inspect its contents.

### How it relates to zero-knowledge

The terms overlap but are not identical. End-to-end encryption describes data in transit between parties. Zero-knowledge describes an architecture where the provider cannot read data at rest either. A service can be end-to-end encrypted for messages while still holding keys to other data it stores for you.

### What still leaks

Metadata. Who you communicate with, when, how often, and from where usually remains visible to the provider even when content does not. For a password manager, the equivalent metadata is the list of services you hold accounts with.

### Sources

- [NIST: Computer Security Resource Center glossary](https://csrc.nist.gov/glossary): Canonical terminology used across US computer security guidance.
- [OWASP: Password Storage Cheat Sheet](https://cheatsheetseries.owasp.org/cheatsheets/Password_Storage_Cheat_Sheet.html): Practical guidance for salts, peppers, PBKDF2, Argon2id, and password hashes.