What end-to-end encryption means
With E2EE, plaintext is available only to participants on endpoints. The server delivers ciphertext but still observes some routing metadata.
Protocol matters more than a label
A product cannot assemble custom cryptography from familiar primitives and call it E2EE. It needs a mature protocol, maintained library, test vectors, and review.
Tallkers evaluates MLS/OpenMLS for groups and multiple devices. Until the prototype passes interoperability and security gates, the product does not claim E2EE is enabled.
What E2EE protects
Compromise of delivery storage should not expose message plaintext. Removing a participant and changing epoch protects future messages from the removed device.
But a device that already decrypted content may have copied it. Rotation does not erase a participant's past knowledge.
Trade-offs
Server-side search, antivirus scanning, and previews conflict with strict E2EE. They cannot all be promised without a separate recovery or inspection mode.
Native apps offer a more persistent code boundary than JavaScript delivered by a server on every browser visit.
This guide explains verifiable product principles and is not legal advice.