bftcosi

Documentation

Overview

Package bftcosi store a novel way of scaling BFT for high scale internet applications especially blockchains

Index

• type Announce
• type BFTSignature
• type ChallengeCommit
• type ChallengePrepare
• type Commitment
• type ProtocolBFTCoSi
  • func NewBFTCoSiProtocol(n *sda.TreeNodeInstance, verify VerificationFunction) (*ProtocolBFTCoSi, error)
  • func (bft *ProtocolBFTCoSi) Dispatch() error
  • func (bft *ProtocolBFTCoSi) RegisterOnDone(fn func())
  • func (bft *ProtocolBFTCoSi) RegisterOnSignatureDone(fn func(*BFTSignature))
  • func (bft *ProtocolBFTCoSi) Signature() *BFTSignature
  • func (bft *ProtocolBFTCoSi) Start() error
• type Response
• type RoundType
• type VerificationFunction

Types

type Announce

type Announce struct {
	*cosi.Announcement
	TYPE    RoundType
	Timeout uint64
}

Announce is the struct used during the announcement phase (of both rounds)

type BFTSignature

type BFTSignature struct {
	// cosi signature of the commit round.
	Sig *cosi.Signature
	Msg []byte
	// List of peers that did not want to sign.
	Exceptions []cosi.Exception
}

BFTSignature is what a bftcosi protocol outputs. It contains the signature, the message and some possible exceptions.

type ChallengeCommit

type ChallengeCommit struct {
	TYPE RoundType
	*cosi.Challenge
	// Signature is the basic signature Challenge / response
	Signature *cosi.Signature
	// Exception is the list of peers that did not want to sign. It's needed for
	// verifying the signature. It can not be spoofed otherwise the signature
	// would be wrong.
	Exceptions []cosi.Exception
}

ChallengeCommit is the challenge used by BftCoSi during the "commit" phase. It contains the basic challenge (out of the block we want to sign) + the signature of the "prepare" round. It also contains the exception list coming from the "prepare" phase. This exception list has been collected by the root during the response of the "prepare" phase and broadcast it through the challenge of the "commit". These are needed in order to verify the signature and to see how many peers did not sign. It's not spoofable because otherwise the signature verification will be wrong.

type ChallengePrepare

type ChallengePrepare struct {
	TYPE RoundType
	*cosi.Challenge
	Msg []byte
}

ChallengePrepare is the challenge used by ByzCoin during the "prepare" phase. It contains the basic challenge plus the message from which the challenge has been generated.

type Commitment

type Commitment struct {
	TYPE RoundType
	*cosi.Commitment
}

Commitment is the commitment packets that is sent for both rounds

type ProtocolBFTCoSi

type ProtocolBFTCoSi struct {
	// the node we are represented-in
	*sda.TreeNodeInstance
	Msg []byte
	// contains filtered or unexported fields
}

ProtocolBFTCoSi is the main struct for running the protocol

func NewBFTCoSiProtocol

func NewBFTCoSiProtocol(n *sda.TreeNodeInstance, verify VerificationFunction) (*ProtocolBFTCoSi, error)

NewBFTCoSiProtocol returns a new bftcosi struct

func (*ProtocolBFTCoSi) Dispatch

func (bft *ProtocolBFTCoSi) Dispatch() error

Dispatch listens on all channels and implements the sda.ProtocolInstance interface.

func (*ProtocolBFTCoSi) RegisterOnDone

func (bft *ProtocolBFTCoSi) RegisterOnDone(fn func())

RegisterOnDone registers a callback to call when the bftcosi protocols has really finished

func (*ProtocolBFTCoSi) RegisterOnSignatureDone

func (bft *ProtocolBFTCoSi) RegisterOnSignatureDone(fn func(*BFTSignature))

RegisterOnSignatureDone register a callback to call when the bftcosi protocol reached a signature on the block

func (*ProtocolBFTCoSi) Signature

func (bft *ProtocolBFTCoSi) Signature() *BFTSignature

Signature will generate the final signature, the output of the BFTCoSi protocol.

func (*ProtocolBFTCoSi) Start

func (bft *ProtocolBFTCoSi) Start() error

Start will start both rounds "prepare" and "commit" at same time. The "commit" round will wait till the end of the "prepare" round during its challenge phase.

type Response

type Response struct {
	*cosi.Response
	Exceptions []cosi.Exception
	TYPE       RoundType
}

Response is the struct used by ByzCoin during the response. It contains the response + the basic exception list.

type RoundType

type RoundType int32

RoundType is a type to know if we are in the "prepare" round or the "commit" round

const (
	// RoundPrepare is the first round (prepare)
	RoundPrepare RoundType = iota
	// RoundCommit is the final round (Commit)
	RoundCommit
)

type VerificationFunction

type VerificationFunction func([]byte) bool

VerificationFunction can be passes to each protocol node. It will be called (in a go routine) during the (start/handle) challenge prepare phase of the protocol