Browse Definitions :
Definition

consensus algorithm

A consensus algorithm is a process in computer science used to achieve agreement on a single data value among distributed processes or systems. Consensus algorithms are designed to achieve reliability in a network involving multiple unreliable nodes. Solving that issue -- known as the consensus problem -- is important in distributed computing and multi-agent systems.

To accommodate this reality, consensus algorithms necessarily assume that some processes and systems will be unavailable and that some communications will be lost. As a result, consensus algorithms must be fault-tolerant. They typically assume, for example, that only a portion of nodes will respond but require a response from that portion, such as 51%, at a minimum.

Applications of consensus algorithms include:

  • Deciding whether to commit a distributed transaction to a database.
  • Designating node as a leader for some distributed task.
  • Synchronizing state machine replicas and ensuring consistency among them.

Consensus algorithms support many real-world systems including Google's PageRank, load balancing, smart grids, clock synchronization and drone control.

Blockchain, the distributed ledger most commonly associated with Bitcoin, also relies on consensus algorithms to reach agreement among nodes. A blockchain can be thought of as a decentralized database that is managed by distributed computers on a peer-to-peer (P2P) network. Each peer maintains a copy of the ledger to prevent a single point of failure (SPOF). Updates and validations are reflected in all copies simultaneously.

Bitcoin uses the proof of work algorithm (PoW) to ensure security in a trustless network, by including mechanisms that ensure that the effort of mining is represented within the block submitted by the miner. Software on the computers of miners accesses their processing capacity to solve transaction-related algorithms. The block is an encrypted hash proof of work that is created in a compute-intensive process. Although any party can submit a chain of blocks to the ledger, the amount of computing resources required to fake consensus is too great to make it worthwhile to a dishonest party.

Other common consensus algorithms include the practical Byzantine fault tolerance algorithm (PBFT), the proof-of-stake algorithm (PoS) and the delegated proof-of-stake algorithm (DPoS).

This was last updated in August 2017

Continue Reading About consensus algorithm

SearchNetworking
  • virtual network functions (VNFs)

    Virtual network functions (VNFs) are virtualized tasks formerly carried out by proprietary, dedicated hardware.

  • network functions virtualization (NFV)

    Network functions virtualization (NFV) is a network architecture model designed to virtualize network services that have ...

  • overlay network

    An overlay network is a virtual or logical network that is created on top of an existing physical network.

SearchSecurity
  • X.509 certificate

    An X.509 certificate is a digital certificate that uses the widely accepted international X.509 public key infrastructure (PKI) ...

  • directory traversal

    Directory traversal is a type of HTTP exploit in which a hacker uses the software on a web server to access data in a directory ...

  • malware

    Malware, or malicious software, is any program or file that is intentionally harmful to a computer, network or server.

SearchCIO
  • chief transformation officer (CTO)

    Chief transformation officer is an executive role, often in the C-suite, that focuses on bringing about change as well as growth ...

  • data latency

    Data latency is the time it takes for data packets to be stored or retrieved. In business intelligence (BI), data latency is how ...

  • chief data officer (CDO)

    A chief data officer (CDO) in many organizations is a C-level executive whose position has evolved into a range of strategic data...

SearchHRSoftware
SearchCustomerExperience
  • implementation

    Implementation is the execution or practice of a plan, a method or any design, idea, model, specification, standard or policy for...

  • first call resolution (FCR)

    First call resolution (FCR) is when customer service agents properly address a customer's needs the first time they call.

  • customer intelligence (CI)

    Customer intelligence (CI) is the process of collecting and analyzing detailed customer data from internal and external sources ...

Close