I was thinking a DoS might be a problem. If you could prevent the p2p network broadcasting or receiving broadcasts, maybe you could be the only person able to proceed with minting. If you could keep that up for a while you could reduce the difficulty and create bitcoins with lower cost. A full enough DoS maybe difficult to do as the network is p2p. Also maybe if you could temporarily come in with significantly more compute power than the rest of the network - eg rent ec2's entire gpcpu farm for a little while, or use of a huge bot farm, you could undo transactions. If those transactions were you selling bitcoins, you could then sell them again. eg buy, then sell $100k coins (minus the spread/fluctuation), rent $50k worth of compute for a while; sell the $100k of coins again ... profit :) Adam On Sun, Jun 12, 2011 at 12:16:01PM +0200, Eugen Leitl wrote:

How safe is the bitcoin cryptosystem and the communication network against targeted attacks?

_______________________________________________ cryptography mailing list cryptography@randombit.net http://lists.randombit.net/mailman/listinfo/cryptography ----- End forwarded message ----- -- Eugen* Leitl <a href="http://leitl.org">leitl</a> http://leitl.org ______________________________________________________________ ICBM: 48.07100, 11.36820 http://www.ativel.com http://postbiota.org 8B29F6BE: 099D 78BA 2FD3 B014 B08A 7779 75B0 2443 8B29 F6BE