Society · Coordination

Consensus

Distributed agreement process

Definition

Mechanism

A distributed protocol allowing a set of agents to agree on a single data value or state transition. It orchestrates Vote exchange and uses Quorum to validate the result. It ensures safety and liveness in an adversarial network, accepting a Proposal and yielding a Value.

Preconditions

  1. Group of agents is defined (Membership List)
  2. Communication channel is available
  3. Proposal received

Postconditions

  1. A single Value is committed to the shared state
  2. All agents are notified of the Value

Invariants

  1. Agreement: All correct agents who decide must decide the same Value.
  2. Validity: If all agents propose V, then the Value must be V.
  3. Termination: Eventually, every correct agent decides on a Value.

Risks

Failure modes

  1. Split Brain

    Network partition causes two subgroups to reach different Values.

  2. Liveness Failure

    The system stalls and never reaches agreement on the Proposal.

  3. Sybil Attack

    One malicious actor creates multiple identities to sway the Vote.

  4. Byzantine Failure

    Agents lying or acting maliciously to prevent consensus.

Caution

Governance decisions susceptible to coordinated voting blocs.

Relationships

Builds on

Accepts

Infrastructure

Proposal

A suggested course of action

Composes with

Infrastructure

Quorum

Minimum participation threshold

Vote

Provide standard decision mechanism with integrity guarantees

Yields

Infrastructure

Value

A measure of utility

Used by

References

Reference

Identity

Ref
Consensus#b9a5
Sema ID
sema:Consensus#mh:SHA-256:b9a51a8b58edf41b9990f962ee403dbc03c6dd380d6bf178cf5403666ec77d32
Ring
0
Tier
1
Updated
2026-11-11
Supersedes
  • sema:Consensus#mh:SHA-256:7216e0e528262020ff05fa26124a8db9fcb14613fde05ddd0b2eb393958c4211
  • sema:Consensus#mh:SHA-256:b862129bd2b8e4a8aa030b4a62a57343385ee7e3863a0639a3563c9800da75f7
  • sema:Consensus#mh:SHA-256:45f490890803e907aa12e85c4751fed8e7f7273f4530fa35f5bd1713a46e3630
  • sema:Consensus#mh:SHA-256:ec3034a2309a89ac077741967abce0cc1301ec49028d96203c9b6403348f1540