Privacy Pools can indeed have a very large anonymity set, but "large" and "fully anonymous" are separated by multiple real-world analysis methods. No matter how large the anonymity set is, it cannot fully block correlation analysis based on behavior patterns and metadata, nor the centralization risk of trusting an Association Set Provider.
Why a Large Anonymity Set Does Not Mean Untraceable
On-chain privacy tools (including Tornado Cash before and Privacy Pools now) offer "probabilistic anonymity," not "guaranteed invisibility." Outside observers cannot mathematically prove that Address A is Address B, but they can use several heuristics to build highly suspicious links.
The most typical method is the "same amount + time window" heuristic: when someone deposits a specific amount of ETH, and shortly after (for example within 30 minutes to 2 hours) another address withdraws the same amount of ETH from the same pool, analysis tools flag a strong link between these two addresses.
According to on-chain data analysis, about 10.9% of ETH withdrawals on Ethereum mainnet match this "same amount + time window" heuristic, and the share is even higher in pools with lower liquidity. This means even if you blend into a large anonymity set, as long as your deposits and withdrawals leave matching traces in amount and time, analysis tools may still target you.
How Privacy Pools Respond and What Risks Remain
The protocol itself also uses technical methods to fight this tracking. For example, an old user can withdraw the same amount right after you deposit, creating a fake link to confuse analysis tools. This is called a "decoy withdrawal" mechanism. Public data shows that more than 160 such decoy candidate addresses have appeared on a single chain.
Even so, two core risks remain:
- Association Set Provider (ASP) centralization risk: The ASP defines "compliant addresses" and generates association sets, so it holds the power to filter and label addresses. If the ASP has censorship bias or is infiltrated by certain institutions, user transaction behavior may be placed under surveillance. As some analyses point out, providing this kind of association set requires professional blockchain forensics background, which means only a small number of professional institutions can act as ASPs.
- Exposure risk from the "Ragequit" exit option: The protocol includes a function called "Ragequit" for emergencies when you are excluded from the compliant set by the ASP and cannot withdraw normally. But when using this function, you need to prove that you know the secret information of the deposit, which directly reveals exactly which deposit is yours and therefore exposes your identity. It is a last escape route, but once used, your privacy disappears instantly.
Practical Check Suggestions
- Change your operating habits: Avoid the "same amount, one in and one out within a short time window" pattern that is easy for correlation analysis.
- Watch the ASP: Pay attention to which ASP the privacy pool uses and whether its rules change. If you become ineligible, you can only exit through the privacy-exposing Ragequit function.
How to Verify
To get a direct feel for the risk, you can visit blockchain data analysis platforms such as Envio and use their privacy pool correlation analysis dashboards to see how many deposit and withdrawal addresses can be easily linked together.
