Taint Analysis
A forensic technique that traces how 'tainted' funds from a known illicit source spread across subsequent transactions and addresses.
Taint analysis is a chain analysis (see Kaavon's "Chain Analysis" glossary definition) technique that starts from funds known to originate from an illicit source — such as a hack, scam, or sanctioned address — and traces how that "taint" propagates as the funds move, split, and combine with other funds across subsequent transactions. Different taint models assign taint proportionally (so mixing tainted funds with clean funds dilutes but doesn't eliminate the taint) or use stricter all-or-nothing rules depending on the methodology.
Taint analysis underpins how exchanges and compliance tools flag incoming deposits connected, even indirectly, to known illicit activity, and is part of why funds from a hack are often difficult to cash out cleanly even after being moved through many intermediate addresses or a mixer (see Kaavon's dedicated glossary entries on privacy tools). Its main limitation is that taint models are methodology-dependent and can produce false positives, flagging funds that passed through a tainted address incidentally without any wrongdoing by the current holder.
Examples
- An exchange's compliance system might flag a deposit as high-risk if taint analysis traces a meaningful share of the funds back to a known hack, even several hops removed.
- Different taint analysis methodologies can reach different conclusions about the same transaction history, since there's no single universally agreed-upon way to model how taint spreads and dilutes.