Byzantine fault

The problem is complicated by the presence of treacherous generals who may not only cast a vote for a suboptimal strategy; they may do so selectively.

This work was done in 1978 in the context of the NASA-sponsored SIFT[5] project in the Computer Science Lab at SRI International.

These results, together with a later proof by Leslie Lamport of the sufficiency of 3n using digital signatures, were published in the seminal paper, Reaching Agreement in the Presence of Faults.

To make the interactive consistency problem easier to understand, Lamport devised a colorful allegory in which a group of army generals formulate a plan for attacking a city.

The name was changed, eventually settling on "Byzantine", at the suggestion of Jack Goldberg to future-proof any potential offense-giving.

Despite the allegory, a Byzantine failure is not necessarily a security problem involving hostile human interference: it can arise purely from physical or software faults.

Given that there is mathematical proof that this is impossible, these claims need to include a caveat that their definition of BFT strays from the original.

For systems that have a high degree of safety or security criticality, these assumptions must be proven to be true to an acceptable level of fault coverage.

When providing proof through testing, one difficulty is creating a sufficiently wide range of signals with Byzantine symptoms.

[27][28] Byzantine errors were observed infrequently and at irregular points during endurance testing for the newly constructed Virginia class submarines, at least through 2005 (when the issues were publicly reported).

[32] Byzantine Fault Tolerance (BFT) is a crucial concept in blockchain technology, ensuring that a network can continue to function even when some nodes[33] (participants) fail or act maliciously.

This tolerance is necessary because blockchains are decentralized systems with no central authority, making it essential to achieve consensus among nodes, even if some try to disrupt the process.

These protocols ensure that the majority of honest nodes can agree on the next block in the chain, securing the network against attacks and preventing double-spending and other types of fraud.

Instead of relying on a central authority, the network's security depends on the ability of honest nodes to outnumber and outmaneuver malicious ones.

For example, SAFEbus can achieve Byzantine fault tolerance within the order of a microsecond of added latency.