Enterprise Blockchain Platforms Flashcards

A consortium of competing manufacturers wants to build a supply chain solution on Hyperledger Fabric. They need to share transactional data with their direct suppliers and logistics partners, but want to ensure that pricing and quantity details remain confidential from other competing manufacturers on the same network. Which Hyperledger Fabric feature is specifically designed to address this requirement?

Answer: Channels

Hyperledger Fabric's channels act as private 'sub-networks' within the main blockchain network. [5, 12] By creating a channel that includes only the manufacturer, its suppliers, and its logistics partners, all transactions and ledger data for that specific supply line are isolated and kept confidential from other members (like competing manufacturers) who are not part of that channel. [3, 6, 10]

Which enterprise blockchain platform is architecturally designed around a 'need-to-know' principle, where transaction data is NOT broadcast to all nodes on the network but is instead sent directly and privately only to the participants involved in that specific transaction?

Answer: R3 Corda

R3 Corda is uniquely designed to avoid global broadcasting of transactions. Instead, it uses a peer-to-peer communication model where transaction details are shared only on a 'need-to-know' basis with the parties directly involved and any necessary notaries. [16, 18, 23] This approach provides a high degree of privacy by default, as no node has a complete view of all transactions on the network. [17]

A financial services consortium is using ConsenSys Quorum to settle private transactions between member banks. Which component is primarily responsible for managing the encryption, decryption, and secure distribution of the private transaction payloads to only the authorized participants?

Answer: Tessera

Tessera is the private transaction manager used by ConsenSys Quorum (and Hyperledger Besu). [1] Its core function is to handle the privacy of transactions by encrypting the payload, securely distributing it to the intended recipients off-chain, and replacing the private data on the main chain with a hash, ensuring only authorized parties can view the sensitive details. [2, 4]

In Hyperledger Fabric's transaction lifecycle, what is the specific role of an 'endorsing peer'?

Answer: To execute a chaincode transaction proposal, sign the result, and return it to the client.

The endorsing peer's primary role is to receive a transaction proposal from a client application, simulate the transaction by executing the specified chaincode, and then sign the read-write set (the results). This signed proposal response, or 'endorsement', is sent back to the client. It does not commit the transaction to the ledger at this stage. [8, 21]

An enterprise is evaluating blockchain platforms and notes a key difference in their underlying data structures. One platform, R3 Corda, is described as using a UTXO (Unspent Transaction Output)-like model, whereas platforms like Ethereum and Quorum use an account-based model. What is a primary characteristic of Corda's UTXO-like model?

Answer: Transactions consume existing states as inputs and produce new states as outputs, which are then individually tracked.

Unlike the account model which tracks balances in a global state, Corda's ledger model is similar to the UTXO model. Each transaction consumes one or more existing states (inputs) and creates new, immutable states (outputs). The current state of the ledger is the collection of all unconsumed states, providing a clear chain of provenance for each asset without a central balance sheet. [25, 29]

A consortium of four organizations (A, B, C, D) is operating a Hyperledger Fabric network. A specific chaincode requires that for any transaction to be valid, it must be approved by at least one organization from the pair (A, B) AND organization C. Which Fabric mechanism is used to formally define and enforce this rule before a transaction is committed to the ledger?

Answer: An endorsement policy

An endorsement policy is defined for a chaincode and specifies which peers, and by extension which organizations, must execute and sign a transaction to deem it valid. [27] The policy can define complex rules, such as `AND(OR('A.member', 'B.member'), 'C.member')`, which directly implements the scenario described. This check is performed by committing peers before a block is written to the ledger. [22]