The general idea is that the transactions are evaluated for their uniqueness by the notary service and, if they are unique (that is, unique transaction inputs), they are signed by consensus services as valid.
There can be single or multiple clustered notary services running on a Corda network.
Human-Readable Addresses for the Blockchain World (Part 2)
Various consensus algorithms like PBFT or Raft can be used by notaries to reach consensus.
There are two main concepts regarding consensus in Corda: consensus over state validity and consensus over state uniqueness.
The first concept is concerned with the validation of the transaction, ensuring that all required signatures are available and states are appropriate.
The second concept is a means to detect double-spend attacks and ensures that a transaction has not already been spent and is unique.
Consensus The consensus model in Corda is quite simple and is based on notary services that are discussed in a later section of this chapter. The general idea is that the transactions are evaluated for their uniqueness by the notary service and, if they are unique (that is, unique transaction inputs), they are signed by consensus services as valid. There can be single or multiple clustered notary services running on a Corda network. Various consensus algorithms like PBFT or Raft can be used by notaries to reach consensus. There are two main concepts regarding consensus in Corda: consensus over state validity and consensus over state uniqueness. The first concept is concerned with the validation of the transaction, ensuring that all required signatures are available and states are appropriate. The second concept is a means to detect double-spend attacks and ensures that a transaction has not already been spent and is unique.
Why This Matters for Blockchain Technology
Understanding Consensus is not just an academic exercise — it has real-world implications for how blockchain systems are designed, deployed, and secured. Whether you are a developer building decentralized applications, a business leader evaluating blockchain adoption, or a curious learner exploring the technology, this knowledge provides a critical foundation.
Key Points to Remember
- The general idea is that the transactions are evaluated for their uniqueness by the notary service and, if they are unique (that is, unique transaction inputs), they are signed by consensus services as valid.
- There can be single or multiple clustered notary services running on a Corda network.
- Various consensus algorithms like PBFT or Raft can be used by notaries to reach consensus.
- There are two main concepts regarding consensus in Corda: consensus over state validity and consensus over state uniqueness.
Conclusion
Consensus represents one of the many innovative layers that make blockchain technology so powerful and transformative. As distributed systems continue to evolve, a solid understanding of these core concepts becomes increasingly valuable — not just for developers, but for anyone building, investing in, or working alongside blockchain-powered systems.
Whether you are just starting your blockchain journey or deepening existing expertise, mastering these fundamentals gives you the tools to think clearly about decentralized systems and make smarter decisions in this rapidly evolving space.