A consensus problem for multi-agent systems under jamming attacks is considered. Specifically, the agents are assumed to communicate over a shared network, where transmissions may fail at certain times due to jamming. We propose stochastic communication protocols so that the agents attempt to communicate with each other at random time instants that are unknown by the attacker. We obtain sufficient finite-time practical consensus conditions. Through a probabilistic analysis, we show that our communication protocols allow consensus under a class of attacks that were previously not considered. We demonstrate the efficacy of our results by considering two different strategies of the attacker: a deterministic attack strategy and a more malicious communication-aware strategy.