Metadata
Data about data — who communicated, when, file author fields, message size. Often more revealing than message content and not always protected by encryption alone.
Metadata is data about a communication rather than its content: who contacted whom, when, from where, how large the transfer was — plus incidental fields like document author names or photo EXIF tags.
Why it matters
Encryption protects content, but metadata often stays visible, and it is frequently the more revealing half. Connection timestamps can link a poster to an event; a photo’s EXIF block can carry GPS coordinates; transfer sizes can fingerprint which page of a site someone browsed over an encrypted channel. Investigations documented in court records have repeatedly leaned on exactly these traces rather than on broken cryptography.
Common mistake
Assuming Tor covers it. Tor reduces network-level metadata — an observer no longer sees your IP talking to a destination — but it does nothing for application-level traces: an uploaded file keeps its EXIF data, a reused username links accounts, and a regular login schedule is itself a pattern. That residue is an OPSEC problem, and measuring what remains visible is the domain of traffic analysis.
Category: Privacy