Just recently researchers from the University College London published a paper about the patterns found in “shielded” and “unshielded” Zcash transactions. The study explains when users switch between these types of addresses anonymity is degraded. The team concludes that while Zcash transactions can be private, it’s also possible to diminish privacy if certain usage patterns are chosen by the Zcash user.
We conclude that while it is possible to use Zcash in a private way, it is also possible to shrink its anonymity set considerably by developing simple heuristics based on identifiable patterns of usage.
Read the full article here: https://news.bitcoin.com/research-paper ... h-privacy/