Andes, to have control of 50% of the network you need to deploy 101% processing power (you´ll end up having 50,5%)

But, why thinking there will only be 1 dishonest entity?  If there is one, there could be more, each one of them would have their own self-interest on controlling the network.   If a lot of "dishonest" entities with great processing power try to control the network, they would make the 51% attack less probable themselves.