A Byzantine Generals’ Problem is a situation where you need consensus on a certain action or strategy from all relevant participants, but you can’t trust or verify the communication/messages from the other participants. An example is in a war where you have your allied armies in different locations and you will defeat the enemy forces if you all attack or retreat at the same time. However, if you receive communication that you will attack, but your allied armies have been deceptive towards you and retreat, you will all eventually lose. The term was initially phrased by Leslie Lamport, Robert Shostak and Marshall Pease in their 1982 paper, “The Byzantine Generals Problem”.
In the cryptocurrency world, the Byzantine Generals Problem is the situation where network participants issue incorrect information to others about transaction taking place that have not really taken place. This could lead to network failure, if it hadn’t been for the Byzantine Fault Tolerance.