School of Computing Science, University of Newcastle upon Tyne From Crash Tolerance to Authenticated Byzantine Tolerance: a Structured Approach, the Cost and Benefits Mpoeleng, D., Ezhilchelvan, P.D. and Speirs, N.A. Technical Report Series CS-TR-824 January 2004 Copyright c 2004 University of Newcastle upon Tyne Published by the University of Newcastle upon Tyne, School of Computing Science, Claremont Tower, Claremont Road, Newcastle upon Tyne, NE1 7RU, UK.