Available cooperation mechanisms either use bilateral multi-step negotiation or auctioning.
Negotiations encourage agents to reason about the interests of their opponents.
Thus, negotiations suffer from counterspeculations. Both mech-anisms do not promote agents to tell the truth. Therefore, we propose to use a trustbroker to mediate between the agents. We introduce three symmetric, negotiation free one-step protocols to carry out a sequence of decisions for agents with possibly conflicting interests. The proto-cols achieve substantially better overall benefit than random or hostile selection, and they avoid lies.