Quote from: casascius on March 11, 2011, 01:00:50 AM

From a new block, there wouldn't be a history. Nobody would know whom to ask where he got his BTC.

Compare to BTC acquired from a reputable exchanger. It might be possible to tell what exchanger the BTC came from based on other transactions it was combined with. Someone goes and gives their real name to a KYC-following BTC exchanger thinking they are buying "anonymous money", and then they go do something terrible with it thinking there's no link to the BTC purchase, but there is. The BTC he bought may very well have enough traceable history that would lead to the place he bought it, there is just no way to know for sure.

At least if he got BTC from a new block, that risk would be greatly lessened, because one could be sure there was no public information available about where the BTC came from.

Yes, I understand that.

I was arguing that transferring the coins from the new block to a new address (provided by the buyer) and then using them for whatever shady goal one may have in mind is just as anonymous as using them from the unspent block. They would show one more transaction in their history, but as long as they are not mixed with any other coin there would still be no one to interrogate.

Of course the "not mixing" part may require some attention, and possibly a patched client, but it will still be easier and safer than sharing private keys for the block.

So, I would say that if anonymity is what you are interested in, simply transferring the newly mint coins to a buyer's address is equivalent to actually transferring the block. Or am I missing something?