Zero Knowledge Digital IDs Are Not a Silver Bullet

Zero knowledge proofs are often pitched as a magic shield for digital identity. The idea that you can prove something about yourself-like being over 18 or holding a valid credential-without revealing anything else sounds perfect. The elegance is appealing. But these systems can introduce risks, even when you wrap everything in ZK.

For one, there's always the question of correlation. Even if you don't leak your actual identity, repeated use of the same proof or the same wallet can let someone link your activities together. Suddenly, you have a persistent identity trail, just abstracted a layer higher. It's not your name, but it's still you, at least as far as the system is concerned. There's also the issue of coercion and social engineering. If someone is forced to generate a proof or hands over their device, ZK doesn't help. The privacy is cryptographic, not physical or social.

Another weird edge case is about revocation. If you want to revoke or update a credential, it's tricky to do that without introducing a backdoor or extra metadata. Suddenly, you're juggling between privacy and admin control, and those tradeoffs are hard to get right. The surface area for subtle bugs or misconfigurations is bigger than people think.

All of this makes me cautious about digital ID, even when it's ZK-wrapped. The technology is powerful, but I think it's easy to overestimate how much risk it actually eliminates. Design is everything here. If the UX or the underlying assumptions shift even a little, you can leak more than you intended. I try to treat ZK as a tool, not a shield. It helps, but the real risk often hides in how people use the system, not just the math.