Quote from: [mike] on January 30, 2011, 04:42:29 PM

I mean one "pro" mixer rather than several mixers.

In my model I have two things: nodes and mixnets. Each node belongs to (is operated and controlled by) a single entity (individual/organization). A mixnet is made up of any number of nodes greater than 1. (I also have clients and transactions (chained and not) but let's keep this simple.)

What is a 'mixer'? Is it a node or a mixnet or something else? Is it controlled by a single entity or by more than one?

Quote from: [mike] on January 30, 2011, 04:42:29 PM

Running a mixer is risky because various government regulations in US/EU require you to know who your customer is once you're doing transactions of above a certain level, I think.

I will read more about that once I get the chance, but here's the thing: I don't think any of those regulations apply because Bitcoin isn't a currency and mixnet nodes don't have customers, in the commonly understood definitions of those words. That's not a legal opinion and obviously node operators will have do their homework regarding their local jurisdiction before they start. I just expect that in many cases it won't be a problem until the law begins to recognize Bitcoin as a currency.

Quote from: [mike] on January 30, 2011, 04:42:29 PM

for the database it's possible to obfuscate

I may have misunderstood, but it looks like your DB has two garbage columns but then the two bitcoin addresses, in order and in plaintext. An attacker who seizes the DB will not have to compute keys or values and do lookups, he'll just dump the entire DB, discard the first two columns, and use column A as his key and B as his value.