On November 30th, 2016 the R3 foundation publicly released the code for its Corda decentralized ledger platform along with a bevy of developer tools, repositories, and community features including both a Slack and a Forum. A little under a month out, and it is safe to say that the Corda platform is well underway under the guidance of the well known Mike Hearn who also wrote the technical whitepaper on Corda.
Notably, in this white paper and in the code, the development team has taken a new approach to decentralized ledgers: Corda is not a blockchain. Many aspects of Corda resembles something in blockchain, Corda is not a block chain. Transaction races are deconflicted using pluggable notaries. A single Corda network may contain multiple notaries that provide their guarantees using a variety of different algorithms. Thus Corda is not tied to any particular consensus algorithm.
This is a fascinating addition to the distributed/decentralized ledger race in that one of the most well known consortia in the blockchain space has moved away from using blocks of transactions linked together. This is an intriguing peer-2-peer architecture since the transactions utilize the UTXO input/output model which is very similar to the transaction system used in more traditional blockchains such as Bitcoin but the storage and verification do not get written into blocks.
Likewise, Corda does not contain a general gossip protocol which broadcasts all transactions to the network. The validation function of the contract code only needs the validation chain of each individual transaction that it is working with and transactions that occur on the ledger are not broadcast to a public depository or written into blocks. Likewise, the consensus protocol of each deployment of Corda can change allowing the platform to conform to the needs & specifications of each client. These simplifications allow Corda to sidestep the scalability issues dogging blockchains like Bitcoin while allowing for a system that conforms to the needs of an enterprise rather than forcing a multi-gajillion dollar company to fundamentally change the way they need to handle payments.
Corda architecture is a highly client-sensitive private ledger that allows for nodes tailored to the kinds of transactions that their operators need. The ledger allows for mistakes to be fixed and states to be edited and is stored on a H2 database engine interfaced with the SQL relational database language. However, any changes to states must also conform and be validated by the code. This realist approach to an enterprise distributed ledger as it takes into account the need for both familiar integration, headroom for the inevitable human mistake, and a single truth between parties. As mentioned before, the state system also contains a direct reference to an actual legal document that governs this truth.
