Linux Foundation Hyperledger Fabric Certified Practitioner HFCP Exam Questions

Answer : D

In Hyperledger Fabric, the identity solution that manages user identities and authenticates participants on the network is facilitated by Membership Service Providers (MSPs). MSPs are crucial for defining the rules by which identities are validated, authenticated, and allowed access to the network. MSPs handle the issuance of certificates and define the roles and permissions associated with participant identities, enabling permissioned interactions on the blockchain. This differs from Hyperledger Fabric CA, which primarily issues and revokes certificates as part of identity management but is used in conjunction with MSPs to provide comprehensive identity solutions within the network.

Answer : A

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 .

Answer : D

When a client application uses the Fabric Gateway client API to create a Gateway connection to a Hyperledger Fabric network, it must supply the client's X.509 certificate and private key. The X.509 certificate is used to authenticate the client to the network, confirming the client's identity and permissions. The private key is used for signing transactions, which is necessary for the network to validate the integrity and origin of the transactions submitted by the client. This combination ensures that both the identity of the client is verified and that transactions cannot be tampered with without detection.

Answer : B

Recovering from a failed migration from Kafka to Raft in Hyperledger Fabric involves restoring the state from a backup. This is necessary because once the ordering service is migrated to Raft and begins committing transactions, reverting to Kafka is not supported without a previous backup. If a migration is botched, and a backup was made at the appropriate point, administrators can roll back to this backup to restore the system to its pre-migration state .

Answer : C

When implementing efficient CouchDB queries from chaincode in Hyperledger Fabric, it is important to use indexes effectively and focus on crafting simple queries that avoid full index scans. Operators such as $or, $in, and $regex can lead to performance issues because they often result in full scans of the database or index. Instead, it is recommended to structure queries that make optimal use of indexes, targeting specific key-value pairs or ranges to minimize the amount of data scanned during query execution. This approach helps in maintaining high query performance and reducing the load on the CouchDB database, which is crucial for achieving efficient data retrieval in a blockchain environment.

Answer : D

In Hyperledger Fabric, to enable CouchDB as the state database, the stateDatabase configuration option in the core.yaml file must be changed from goleveldb to CouchDB. This change directs the peer to use CouchDB instead of the default LevelDB for storing the world state, which can then be queried using rich queries and provides additional features like indexing.

Answer : D

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.