Quote from: lunokhod2 on June 10, 2014, 02:08:10 PM

Quote from: SpruceMoosey on June 10, 2014, 01:32:05 PM

Quote from: lunokhod2 on June 10, 2014, 09:29:09 AM

Here's an interesting article on deanonymizing coinjoin.

http://www.coindesk.com/blockchains-sharedcoin-users-can-identified-says-security-expert/

They don't discuss DarkCoin explicitly, but I presume they have the exact same problem.

What exactly is the problem you are hinting? I don't see it.

The article discusses how to deanonymize bitcoin transactions that make use of CoinJoin (which is a simple way of mixing a small number of transactions together in a block). DarkCoin's "darksend" is based on coinjoin, so I presume that it is equally unsafe (but perhaps there are some extra subtleties). The point is: If anoncoin gets zerocoin working, it will be the only truly anonymous coin out there...

I quote from the article:

Quote

Bitcoin users in need of serious transaction privacy should avoid popular services like Blockchains SharedCoin and other CoinJoin implementations, according to a well-known security expert.

Consultant Kristov Atlas, author of the book Anonymous Bitcoin, published a security advisory today saying weaknesses in SharedCoin offered privacy only from unskilled examiners of the bitcoin blockchain and even then, only until more sophisticated analysis tools were made user-friendly enough for the average user to deploy.

Good post, and highlighting of one very important point. Even if most people can't examine the blockchain, one skilled individual is potentially enough to reverse the anonymity. This in itself is not really bad if the users are aware of the risks. If they however believe they are safe, it could lead to disaster.

I have seen some of the drk supporters claim that even if you can infiltrate some of their nodes you will only be able to reverse the anonymity of a few individuals/transactions. They say that as it does not really pose a problem for anyone. Probably because they are not currently in a situation that really requires anonymity.
Depending of the type of transactions revealed, and possibly tied to an identity, it could be the difference between life or death for one or more individuals who actually trusted the technology to keep them anonymous/safe both at the time of the transaction, and beyond.