Metadata¶
Short definition¶
Data around the exchange: accounts, IP, timing, volume, devices or groups.
Concrete example¶
Text is encrypted, but the relay sees a connection at 6 pm and its duration.
What it protects¶
Minimising this data can reduce identification and reconstruction of relationships.
What it does not protect¶
Encrypting the message body does not automatically erase transport or account data.
Why it matters¶
These clues can link people even without reading their text.
Technical details
The observer matters: provider, peer, ISP, push and authorities have different visibility.