CBSA Cheat Sheet 2026

The 30 highest-yield CBSA facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. A Hyperledger Fabric network needs to add a new organization post-deployment. Which process is required? → Submit a channel configuration update transaction signed by existing organizations
2. Which consensus mechanism selects block validators based on the amount of cryptocurrency they lock up as collateral? → Proof of Stake
3. What is the primary trade-off when increasing the number of validators in a BFT consensus protocol? → Better decentralization but exponentially higher communication overhead (O(n²))
4. What is a key concept in this domain? → Correct Concept
5. What regulatory framework in the US classifies a digital asset as a security using the 'Howey Test'? → SEC Securities Act
6. Which Ethereum opcode is used internally when a contract sends Ether using the 'transfer' function, and what is its gas stipend? → CALL with 2300 gas
7. During a Hyperledger Fabric chaincode deployment, a developer receives an 'endorsement policy not satisfied' error. What is the most likely cause? → Insufficient peers from required organizations approved the transaction
8. In Ethereum, which opcode is commonly blamed for the Parity multi-sig wallet freeze of 2017? → DELEGATECALL
9. In a security token offering (STO), what is the role of a transfer agent on the blockchain? → To enforce compliance rules such as KYC/AML whitelists during token transfers
10. A blockchain architect must design a rollback strategy for a failed chaincode upgrade. What is the correct approach in Hyperledger Fabric? → Re-deploy the previous approved chaincode version using the lifecycle endorsement process
11. What is the purpose of a 'block header' in a blockchain block? → It contains metadata including the previous block hash, timestamp, Merkle root, and nonce
12. What is 'chain reorganization' (reorg) and when does it occur? → A network event where a longer competing chain replaces the current canonical chain
13. Ethereum's move from Proof of Work to Proof of Stake (The Merge) primarily aimed to achieve which benefit? → Reduce energy consumption by ~99.95%
14. An NGO distributes aid to refugees using blockchain-based digital wallets. What is the primary advantage over traditional cash aid? → Transparent, auditable disbursement reducing fraud and diversion
15. What is 'key ceremony' in the context of blockchain PKI and why is it important? → A formal witnessed procedure to generate and secure root CA keys
16. A blockchain architect wants to prevent Sybil attacks in a permissionless network without proof of work. Which mechanism is most effective? → Proof of stake with economic slashing
17. In blockchain consensus, what does 'liveness' guarantee? → That the network will eventually make progress and commit new transactions
18. What distinguishes Hyperledger Besu from other Hyperledger projects? → It is an Ethereum client designed for both public and enterprise private networks
19. Which characteristic best defines a 'permissioned' blockchain network architecture? → It restricts participation to identities that have been granted access
20. In a federated Byzantine agreement (FBA) model like Stellar, how is consensus reached? → Each node chooses its own quorum slice, and consensus emerges from overlapping slices
21. When deploying smart contracts on Ethereum mainnet, what is the primary reason to use a proxy upgrade pattern? → To allow contract logic to be updated while preserving the contract address and state
22. Which Hyperledger project focuses on supply chain use cases and provides asset tracking capabilities with event-driven architecture? → Hyperledger Grid
23. Which of the following applies to the domain? → Core Principle
24. Which metric is most commonly used to measure and compare blockchain transaction throughput? → Transactions per second (TPS)
25. In a blockchain network, what problem does the 'nothing-at-stake' attack specifically target? → Proof of Stake consensus mechanisms
26. Which consensus property is violated when two honest nodes permanently disagree on the canonical state of the blockchain? → Safety
27. What does 'gas' represent in the Ethereum blockchain? → A unit measuring computational effort required to execute operations
28. In Hyperledger Besu's QBFT (Quorum Byzantine Fault Tolerance) consensus, what minimum number of validators is required to tolerate one faulty node? → 4
29. Which enterprise blockchain platform was developed by the Digital Asset company and uses DAML as its smart contract language? → Canton (formerly DAML on Ledger)
30. Which Hyperledger Fabric component is responsible for ordering transactions and creating blocks? → Orderer