Quote from: Raulo on July 01, 2011, 12:05:31 PM

Quote from: bcearl on July 01, 2011, 11:59:33 AM

To reverse a 1000 blocks and to catch up then to make the longest block chain takes way more than 50 %, if you want to get it done in a decade.

If you have more than the rest of the network combined (so more than 50% of total power including you), you can grow the alternative chain indefinitely as long as you are ahead. If you have 1% more than the network, you will be 1.44 block ahead per day. If you have 10% more, you will have 14.4 blocks per day. If you have twice the current Bitcoin network, you will reverse 1000 blocks in less than a week.

If you want to do as much of a mess, grow your chain, and wait until the rest of the network caches up with the speed. And then release the alternative chain.

If you want to do that in secret, you will have your own difficulty, which means that the others are twice as fast.

If you don't do that in secret, and you reject blocks of others, they will discover you very early.