The Byzantine Generals Strike Again

Can unanimity be achieved in an unreliable distributed system? This problem was named "The Byzantine Generals Problem," by Lamport, Pease and Shostak [1980]. The results obtained in the present paper prove that unanimity is achievable in any distributed system if and only if the number of faulty processors in the system is: 1) less than one third of the total number of processors; and 2) less than one half of the connectivity of the system''s network. In cases where unanimity is achievable, algorithms to obtain it are given. This result forms a complete characterization of networks in light of the Byzantine Problem.