Linux Foundation HFCP Exam Dumps

When using 'off-line signing' in the Fabric Gateway client API, the cryptographic signature is generated using the message digest. This digest is a hashed representation of the transaction's content, ensuring the integrity and non-repudiation of the transaction as it moves through the Fabric network. This method allows for secure transaction signing without exposing private keys directly on the client-side, aligning with security best practices .

In Hyperledger Fabric, inter-contract communication is possible both within the same channel and across different channels. However, the functionality to alter the state (using PutState) of a chaincode on a different channel is restricted. This limitation is due to the security and isolation principles of channels in Hyperledger Fabric, where each channel represents a separate ledger and state. Transactions within a channel can read and write data freely, subject to endorsement policies, but writing data to another channel's chaincode directly is not permitted. This prevents unauthorized influence on a separate and potentially isolated business process, ensuring that operations within a channel are controlled and secure.

In Hyperledger Fabric, the Gateway service manages the transaction submission process on behalf of the client application. This service simplifies the interaction with the network by abstracting the details of transaction construction, endorsement, and submission. The Gateway service assembles the necessary endorsements according to the relevant chaincode endorsement policies and submits the transaction to the ordering service. This role of the Gateway enhances the usability and efficiency of transaction processing, reducing the complexity for client applications by handling these critical steps internally.

In Hyperledger Fabric, when a transaction that includes the delState('A') function is committed, it results in the removal of the state of the key 'A' from the current state database. However, the history of all transactions that have affected the key 'A' remains intact in the ledger. This operation ensures that while the current state reflects the deletion, the immutability and traceability of the ledger are preserved, allowing for auditability and verification of past states. Options such as setting an empty value to the key or altering the transaction history are not supported, as they would violate the principles of immutability and transparency central to blockchain technology. Therefore, the correct outcome of a delState('A') operation is that the current state of 'A' is deleted, but its transaction history remains accessible in the ledger.

Theidemixgentool is used to create configuration files for the Identity Mixer based MSP (Membership Service Provider) in Hyperledger Fabric.When configuring membership, theidemixgentool creates three directories:/ca/,/msp/, and/user/1. The/ca/directory contains the issuer secret key, issuer public key, and revocation key, which should only be present for a Certificate Authority (CA). The/msp/directory contains the issuer public key and revocation public key, which are required to set up an MSP that verifies Identity Mixer signatures.The/user/directory specifies a default signer configuration1. Therefore, the correct answer is the user directory, which is created alongside the ca and msp directories by theidemixgentool.