Observations and personal opinions from Nothing Research Partner 0x_Todd. The following content does not constitute any investment advice.

A few days ago, Vitalik published an article about privacy, which mentioned an interesting idea. Today, I carefully read the details and share it with you.

It turns out that the simplest way to resolve the Tornado Cash controversy is to add another blacklist and then use cryptography to prove that the source of your funds does not belong to hackers and related addresses.

My views on Tornado Cash have always been very complicated.

I support privacy. After all, it is a bit unpleasant that one address makes all your on-chain history and transactions public.

But the negative thing is that Tornado Tornado objectively provides a convenient place for hackers. Once the funds enter the Tornado, it basically declares that there is no hope of recovery.

I am far from being right-wing enough to think that hackers laundering funds is also as exaggerated as [freedom and power].

But the solution proposed in this paper is too simple:

Just add a whitelist/blacklist and it's done-

Proof of qualification ("I prove that my withdrawal comes from one of these deposits")

Proof of exclusion ("I prove that my withdrawal does not come from one of these deposits").

You can use some cryptographic proof to prove that the source of your funds has nothing to do with the hacker address.

The good address can issue a proof at will, but the hacker address cannot issue this proof.

Then you can use this mixer freely, and then we are more familiar with the link, A address deposits money, B address withdraws money, and creates privacy.

Of course, the entity that maintains the whitelist/blacklist still needs to rely on centralization. This is unavoidable, because it involves the real world, and this entity may be under some pressure in the future.

For example, now Coinbase requires KYC of deposit/withdrawal addresses, so this entity may be subject to regulatory pressure in the future, and the scope of the blacklist may also be greatly increased. However, this is the worst case.

This idea solves my biggest worry, that is, the contradictory mentality towards privacy, which really makes me happy.