[sp332]

51% attack is not the only kind of attack. A "selfish mining" attack can break the system too. http://hackingdistributed.com/2013/11/04/bitcoin-is-broken/ Here's the paper http://arxiv.org/abs/1311.0243

[michaeltoth]

Thanks for the articles. I recall reading about this last year when the paper was published, but I had since forgotten about this form of attack. This is definitely interesting.