CCA Cheat Sheet 2026

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

1. A smart contract uses `tx.origin` for authentication. What attack does this enable? → Phishing via malicious intermediary contract
2. Which nonce characteristic in an Ethereum account would alert a CCA auditor to a potential transaction gap or out-of-order submission? → A nonce sequence with a missing integer (e.g., nonces 1, 2, 4 with no nonce 3)
3. An auditor is reviewing a DeFi protocol that uses a single on-chain price feed from a low-liquidity AMM. Which attack is this protocol most susceptible to? → Flash loan price manipulation
4. Under U.S. law, which of the following best describes how the IRS treats cryptocurrency received as payment for services? → It is treated as ordinary income at fair market value on the date received
5. What is the primary goal of cryptocurrency regulation? → To ensure legal compliance and investor protection
6. Which hashing algorithm does Bitcoin use to generate a transaction ID (TXID)? → SHA-256 applied twice (double SHA-256)
7. Which U.S. agency plays a key role in crypto regulation? → SEC
8. Which threshold triggers an automatic Currency Transaction Report (CTR) filing requirement under U.S. BSA rules? → $10,000 in cash transactions within a business day
9. Which U.S. regulatory body has primary authority over cryptocurrency exchanges that list tokens deemed to be securities? → SEC
10. What type of income is recognized when cryptocurrency is received as payment for goods or services? → Ordinary income
11. In UTXO-based chain analysis, which output type is most commonly identified as a 'change output' returned to the sender? → The output with a non-round amount sent to a previously unused address
12. Which type of wallet arrangement presents the highest operational security risk for a cryptocurrency custodian? → Hot wallet with keys stored on an internet-connected server
13. An auditor reviewing a crypto exchange's transaction monitoring system should assess whether alerts are tuned to detect which typology? → Layering through rapid conversion between multiple cryptocurrencies
14. What does a blockchain transaction include? → Digital signature and transaction details
15. Which best describes a phishing attack in crypto? → Fraudulent attempt to access credentials
16. What is a hash in blockchain? → A cryptographic summary of data
17. Which international body sets the global Anti-Money Laundering and Counter-Terrorism Financing (AML/CTF) standards that most countries adopt for virtual assets? → The Financial Action Task Force (FATF)
18. What is the FIFO method as applied to cryptocurrency cost basis accounting? → The oldest acquired coins are considered sold first
19. What is the purpose of a 'fuzz testing' tool like Echidna in smart contract security? → To generate random inputs and detect property violations automatically
20. When analyzing a Monero transaction, which feature makes traditional blockchain tracing techniques largely ineffective? → Ring signatures, stealth addresses, and RingCT obscure sender, recipient, and amount
21. Which risk specifically arises from using a deterministic wallet (BIP-32 HD wallet) where the master seed is compromised? → All child private keys derived from that seed are compromised simultaneously
22. A VASP operating in multiple EU member states under MiCA can serve all EU customers via which regulatory concept? → Passporting
23. What is a blockchain? → A distributed digital ledger
24. Which blockchain forensic methodology involves submitting a small, deliberate transaction to a suspect address to confirm liveness and later trace any co-spend? → Controlled interaction / probe transaction technique
25. Which property of a public blockchain makes it fundamentally different from traditional financial records for forensic purposes? → Blockchain records are immutable and permanently accessible without a court order
26. A DeFi protocol that pools user funds to generate yield and distributes profits to token holders is most analogous to which traditional regulated entity? → An investment company subject to the Investment Company Act of 1940
27. In Ethereum, what is the role of the 'nonce' field in a transaction? → It prevents replay attacks and ensures transaction ordering per account
28. Which factor most significantly complicates the fair value measurement of a non-fungible token (NFT) for financial reporting purposes? → Thin or illiquid markets with infrequent comparable sales
29. Which verification method allows a lightweight (SPV) client to confirm a transaction without downloading the full blockchain? → Merkle proofs linking the transaction to a block header
30. An auditor notices a cluster of transactions with identical amounts fanning out from one address to hundreds of others. What pattern does this suggest? → A peeling chain or peel chain money laundering technique