mirror of https://github.com/poanetwork/hbbft.git
34 lines
1.6 KiB
Rust
34 lines
1.6 KiB
Rust
//! # Subset algorithm.
|
|
//!
|
|
//! The Subset protocol assumes a network of _N_ nodes that send signed
|
|
//! messages to each other, with at most _f_ of them malicious, where _3 f < N_. Handling the
|
|
//! networking and signing is the responsibility of the user: only when a message has been
|
|
//! verified to be "from node i" (e.g. using cryptographic signatures), it can be handed to the
|
|
//! `Subset` instance.
|
|
//!
|
|
//! Each node proposes an element for inclusion. Under the above conditions, the protocol
|
|
//! guarantees that all correct nodes output the same set, consisting of at least _N - f_ of the
|
|
//! proposed elements.
|
|
//!
|
|
//! ## How it works
|
|
//!
|
|
//! * `Subset` instantiates one `Broadcast` algorithm for each of the participating nodes.
|
|
//! At least _N - f_ of these - the ones whose proposer is not faulty - will eventually output
|
|
//! the element proposed by that node.
|
|
//! * It also instantiates Binary Agreement for each participating node, to decide whether
|
|
//! that node's proposed element should be included in the set. Whenever an element is
|
|
//! received via broadcast, we input "yes" (`true`) into the corresponding `BinaryAgreement` instance.
|
|
//! * When _N - f_ `BinaryAgreement` instances have decided "yes", we input "no" (`false`) into the
|
|
//! remaining ones, where we haven't provided input yet.
|
|
//! * Once all `BinaryAgreement` instances have decided, `Subset` returns the set of all proposed
|
|
//! values for which the decision was "yes".
|
|
|
|
mod error;
|
|
mod message;
|
|
mod proposal_state;
|
|
mod subset;
|
|
|
|
pub use self::error::{Error, FaultKind, Result};
|
|
pub use self::message::{Message, MessageContent};
|
|
pub use self::subset::{Step, Subset, SubsetOutput};
|