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Anonymity Set
Privacy
Set of indistinguishable subjects given an attacker’s observations and prior knowledge.
Definition
An anonymity set is the set of possible senders/receivers consistent with observed signals. Size and diversity matter; correlations (timing, metadata) can shrink the effective set.
In plain English
Set of indistinguishable subjects given an attacker’s observations and prior knowledge.
Why this matters
Why it matters: Small or shrinking anonymity sets enable re-identification and traffic analysis.
Example
Example: Mixing networks increase anonymity sets, but unique behavior patterns can reduce them dramatically.