What is end-to-end encryption?¶

A messaging service may describe its communications as end-to-end encrypted.

Evidential caution: that this means the entire service is invisible and no evidence can exist.

What this means¶

End-to-end encryption is designed so that readable message content is available only at the communicating endpoints, such as the sender’s and recipient’s devices.

The provider may carry the encrypted data without being able to read the message content in transit.

That protection can significantly limit what the provider can supply about the content.

But the message must still be readable somewhere for the participants to use it. Copies may exist on sender devices, recipient devices, linked devices, notifications, exports, screenshots or backups.

The provider may also retain account and service information that is not the readable content. This can include registration details, device or session records, delivery events, group membership and other metadata, depending on the service and retention.

What to check or do next¶

• Preserve the devices and accounts before interacting unnecessarily. Opening applications, reconnecting devices or changing settings may alter synchronisation or message state.
• Do not describe encryption as broken merely because content is found on a device. End-to-end encryption protects the communication path, not necessarily every stored copy.
• Preserve the source and collection method so the conclusion can be reviewed and reproduced.

Evidential limits¶

Encryption does not prove who authored a message. It does not prevent account compromise, linked-device access or evidence being obtained from an endpoint.