CBDH Security & Access Control 4

Question 1

What is stored on the channel ledger for a private data collection write?

Accepted Answer

Only a hash of the private data

Answer

Only hashes go to the channel ledger; real data stays in members' side databases.

Question 2

What does memberOnlyRead set to true in a collection definition do?

Accepted Answer

Restricts chaincode invocation to collection members only for reads by clients

Answer

memberOnlyRead requires that clients reading the data belong to a collection member organization.

Question 3

Which ClientIdentity chaincode API retrieves a custom attribute from the caller's certificate for ABAC?

Accepted Answer

GetAttributeValue

Answer

ClientIdentity.GetAttributeValue reads attributes embedded in the X.509 certificate.

Question 4

Why should chaincode avoid using random numbers or local system time to compute state changes?

Accepted Answer

Different endorsers would produce different results, causing endorsement mismatch

Answer

Chaincode must be deterministic so endorsing peers return identical read/write sets.

Question 5

How can a collection require specific organizations to endorse writes to private data?

Accepted Answer

By a collection-level endorsement policy

Answer

Collections can define their own endorsementPolicy overriding the chaincode-level one.

CBDH - Certified Blockchain Developer Hyperledger Practice Test