Cryptocurrency Knowledge Test — Questions and Answers

Question 1: How does Delegated Proof of Stake (DPoS) differ from standard Proof of Stake?

DPoS uses computational puzzles instead of coin weighting
DPoS selects validators randomly without any voting mechanism
Token holders vote for a fixed set of delegates who produce blocks on their behalf (Correct answer)
DPoS eliminates block rewards entirely and relies on transaction fees

Correct answer: Token holders vote for a fixed set of delegates who produce blocks on their behalf

In DPoS, coin holders elect a small group of trusted delegates who are responsible for validating transactions and producing blocks.

Question 2: What is the ERC-1155 token standard?

A multi-token standard that supports both fungible and non-fungible tokens in one contract (Correct answer)
A standard for wrapping Bitcoin on Ethereum
A standard for stablecoin issuance on Ethereum
A governance token standard used by DAOs

Correct answer: A multi-token standard that supports both fungible and non-fungible tokens in one contract

ERC-1155 is a multi-token standard that allows a single contract to manage both fungible and non-fungible tokens, reducing deployment costs.

Question 3: An investor decides to store the majority of their cryptocurrency holdings for the long term and wants to maximize security against online threats like malware and hacking. Which of the following storage solutions is most appropriate for this goal?

A web-based wallet accessed through a browser extension
A desktop software wallet on an internet-connected computer
A hardware wallet kept in a secure physical location (Correct answer)
A mobile wallet app on their primary smartphone

Correct answer: A hardware wallet kept in a secure physical location

A hardware wallet is a form of cold storage, meaning it keeps the user's private keys offline and isolated from internet-connected devices. This makes it the most secure option for long-term holdings as it is nearly immune to remote attacks, hacking, and malware that affect 'hot wallets' (mobile, web, and desktop wallets).

Question 4: What is 'sharding' as a blockchain scalability solution?

Splitting a single transaction across multiple blocks
Replacing full nodes with lightweight validator sets
Compressing old blockchain data to free disk space
Partitioning the network so each node only processes a subset of transactions (Correct answer)

Correct answer: Partitioning the network so each node only processes a subset of transactions

Sharding divides the blockchain into parallel partitions (shards), each processing its own transactions, dramatically increasing total throughput without every node handling everything.

Question 5: What is the primary cryptographic purpose of a Merkle tree in Bitcoin?

To create zero-knowledge proofs for transaction privacy
To generate new public keys from the wallet's master private key
To efficiently verify that a specific transaction is included in a block without downloading all transactions (Correct answer)
To encrypt transaction data before broadcasting to the network

Correct answer: To efficiently verify that a specific transaction is included in a block without downloading all transactions

Merkle trees allow Simplified Payment Verification (SPV) clients to verify transaction inclusion by checking a logarithmic-length proof path rather than all transactions.

Question 6: Which programming language compiles to EVM bytecode and is primarily used for Ethereum smart contracts?

Rust
Vyper only
Solidity (Correct answer)
TypeScript

Correct answer: Solidity

Solidity is the dominant high-level language for Ethereum smart contracts; it compiles to EVM bytecode and features a JavaScript-like syntax.

Question 7: Which order type guarantees execution but not price in crypto markets?

Market order (Correct answer)
Stop-limit order
Take-profit order
Limit order

Correct answer: Market order

A market order executes immediately at the best available price, guaranteeing fill but not the exact price.

Question 8: What does 'structuring' mean in the context of cryptocurrency compliance violations?

Building a structured financial product based on crypto
Breaking up transactions to avoid triggering reporting thresholds (Correct answer)
Creating a legal entity to hold crypto assets
Organizing a crypto portfolio into different asset classes

Correct answer: Breaking up transactions to avoid triggering reporting thresholds

Structuring (smurfing) is the illegal practice of breaking large transactions into smaller ones to evade CTR or SAR reporting requirements.

Question 9: Why are "brain wallets," where a user creates a private key from a personally chosen passphrase, generally considered a highly insecure method of key management?

They are incompatible with the BIP-39 standard for mnemonic phrases.
They can only generate a single public address, which is bad for privacy.
The hashing process is too complex for most users to remember.
Human-generated passphrases have low entropy and are susceptible to being guessed or brute-forced by attackers. (Correct answer)

Correct answer: Human-generated passphrases have low entropy and are susceptible to being guessed or brute-forced by attackers.

The security of a private key relies on its randomness (entropy). Humans are poor at creating truly random, high-entropy phrases. Attackers can use dictionaries, common quotes, and computational power to guess these human-generated passphrases, calculate the corresponding private key, and steal any associated funds. Properly generated seed phrases from wallet software have a massive amount of entropy, making them computationally infeasible to guess.

Question 10: What is 'Replace-By-Fee' (RBF) in Bitcoin?

An exchange feature to swap coins at better rates
A wallet backup mechanism using fee-based encryption
A protocol allowing an unconfirmed transaction to be replaced by a new version with a higher fee (Correct answer)
A method to replace a mined block with a higher-fee version

Correct answer: A protocol allowing an unconfirmed transaction to be replaced by a new version with a higher fee

RBF (BIP 125) lets a sender broadcast a replacement transaction with a higher fee to incentivize miners to confirm it faster, before the original is mined.

Question 11: What is 'impermanent loss' for a liquidity provider in an AMM?

The loss incurred when a smart contract is hacked
A permanent reduction in LP tokens due to protocol fee burning
The opportunity cost vs. simply holding when token prices diverge after depositing into a pool (Correct answer)
Gas fees paid when adding or removing liquidity

Correct answer: The opportunity cost vs. simply holding when token prices diverge after depositing into a pool

Impermanent loss occurs when the price ratio of pooled tokens changes from the time of deposit, causing the LP's withdrawn value to be less than if they had just held the tokens.

Question 12: An attacker gains control of 52% of the total hashing power on a Proof-of-Work (PoW) blockchain. Which of the following malicious actions can they now successfully execute?

Reverse their own transactions after they appear confirmed, allowing them to double-spend coins. (Correct answer)
Change the fundamental consensus rules of the blockchain, such as the block reward amount.
Steal cryptocurrency from another user's wallet without their private key.
Create new coins out of thin air.

Correct answer: Reverse their own transactions after they appear confirmed, allowing them to double-spend coins.

A 51% attack on a PoW network gives the attacker control over the ordering of transactions and the ability to create a longer, alternative version of the blockchain. This allows them to send coins in a transaction on the main chain, wait for the recipient to consider it confirmed, and then release their longer, private chain where that transaction never happened, effectively reversing it and enabling a double-spend. They cannot create coins beyond the established block reward, steal funds without private keys, or unilaterally change the core protocol rules which are enforced by all nodes on the network.

Question 13: Which of the following is a primary characteristic that distinguishes a private or permissioned blockchain from a public blockchain like Bitcoin?

The requirement for participants to be vetted and granted access. (Correct answer)
The use of cryptographic hashes to link blocks chronologically.
The ability for the ledger to be distributed across multiple nodes.
The immutable nature of recorded transactions.

Correct answer: The requirement for participants to be vetted and granted access.

The core difference between public and private blockchains is access control. Public blockchains are 'permissionless,' allowing anyone to join. Private blockchains are 'permissioned,' meaning participants must be invited and authorized by a central administrator or consortium. The other options are fundamental characteristics of most blockchains, both public and private.

Question 14: What is the primary risk of storing a seed phrase in a cloud service like iCloud or Google Drive?

Cloud services charge fees for storing sensitive files
The seed phrase file format is incompatible with cloud storage
Cloud services automatically share files with government agencies
A breach or unauthorized access to the cloud account exposes the seed phrase and all associated funds (Correct answer)

Correct answer: A breach or unauthorized access to the cloud account exposes the seed phrase and all associated funds

Storing a seed phrase in the cloud means it is only as secure as the cloud account; a compromised account password or cloud breach can drain the wallet.

Question 15: The 'Blockchain Trilemma' refers to the widely held belief that it is difficult for a decentralized network to optimize three key properties at once. Which of the following correctly lists these three properties?

Decentralization, Security, and Scalability (Correct answer)
Immutability, Transparency, and Usability
Mining, Staking, and Hashing
Speed, Cost, and Anonymity

Correct answer: Decentralization, Security, and Scalability

Coined by Vitalik Buterin, the Blockchain Trilemma posits that it is challenging to build a blockchain that is simultaneously decentralized (lacks a central point of failure), secure (resistant to attacks), and scalable (able to process a high volume of transactions). Often, improving one area requires a trade-off in one or both of the others.

Question 16: To create a digital signature for a transaction, a user's wallet software first hashes the transaction data. What is the next step in this process?

The hash is encrypted with the recipient's public key.
The hash is encrypted with the user's private key. (Correct answer)
The hash is broadcast to the network for verification.
The hash is combined with the previous block's hash.

Correct answer: The hash is encrypted with the user's private key.

A digital signature is created by taking the hash of the message or transaction data and then encrypting that hash with the sender's private key. [13, 19, 23] This proves that the owner of the private key authorized the transaction, providing authenticity and non-repudiation.

Question 17: What is the 'Merkle tree' used for in a blockchain?

Generating new private keys for wallet creation
Storing user wallet addresses in an encrypted database
Routing messages between nodes in a peer-to-peer network
Efficiently summarizing and verifying the integrity of all transactions in a block (Correct answer)

Correct answer: Efficiently summarizing and verifying the integrity of all transactions in a block

A Merkle tree is a hash-based data structure that allows efficient and secure verification of large sets of transaction data, with the Merkle root stored in each block header.

Question 18: What is 'rug pull' fraud in the context of DeFi?

When validators pull out of a staking pool suddenly
When liquidity providers remove funds during a market crash
When developers abandon a project and abscond with investor funds after removing liquidity (Correct answer)
A regulatory seizure of DeFi protocol assets

Correct answer: When developers abandon a project and abscond with investor funds after removing liquidity

A rug pull occurs when project developers suddenly withdraw all liquidity from a DeFi pool, leaving investors with worthless tokens and no recourse.

Question 19: What does FATF stand for in cryptocurrency regulation?

Federal Authority for Token Frameworks
Federal Anti-Fraud Team
Foreign Asset Transfer Fund
Financial Action Task Force (Correct answer)

Correct answer: Financial Action Task Force

The Financial Action Task Force (FATF) is an intergovernmental body that sets global AML and counter-terrorism financing standards.

Question 20: What term describes the situation when a blockchain permanently splits into two separate chains due to a protocol disagreement?

Chain merge
Block orphan
Hard fork (Correct answer)
Soft fork

Correct answer: Hard fork

A hard fork introduces backwards-incompatible rule changes, causing nodes that don't upgrade to follow a different chain, resulting in a permanent split.

Question 21: What is TVL (Total Value Locked) a measure of in DeFi?

The total number of token holders on a platform
The maximum transaction size allowed by a protocol
The total trading volume over 24 hours
The total dollar value of assets deposited in a DeFi protocol (Correct answer)

Correct answer: The total dollar value of assets deposited in a DeFi protocol

TVL represents the aggregate value of all assets deposited in a DeFi protocol, used as a key metric for platform adoption and health.

Question 22: What is 'slippage' in the context of a decentralized exchange (DEX)?

A fee charged by liquidity providers for early withdrawal
The delay between submitting a transaction and block confirmation
A penalty for impermanent loss exceeding a threshold
The difference between the expected price of a trade and the price at which it executes (Correct answer)

Correct answer: The difference between the expected price of a trade and the price at which it executes

Slippage occurs when large trades or low liquidity move the pool price between order submission and execution, causing the actual fill price to differ from the quoted price.

Question 23: Which smart contract upgrade pattern keeps the contract logic separate from its storage?

Proxy pattern (Correct answer)
Singleton pattern
Factory pattern
Registry pattern

Correct answer: Proxy pattern

The proxy pattern routes calls through an immutable proxy contract to a replaceable logic contract, allowing upgrades without migrating user balances or addresses.

Question 24: A US-based cryptocurrency exchange identifies a wallet address on its platform that has been added to the Office of Foreign Assets Control (OFAC) Specially Designated Nationals (SDN) list. What is the exchange's immediate required action regarding the assets associated with this wallet?

Convert the assets to a stablecoin and hold them in a separate omnibus account.
Immediately block the assets and report the action to OFAC. (Correct answer)
Reject any new incoming transactions but allow the user to withdraw the existing balance.
Notify the user that they have 10 days to withdraw their assets before the account is closed.

Correct answer: Immediately block the assets and report the action to OFAC.

U.S. persons and entities, including cryptocurrency exchanges, must comply with OFAC regulations. When they identify property or an interest in property (like cryptocurrency) of a person on the SDN list, they are required to immediately block (freeze) those assets. After blocking the assets, they must report the action to OFAC within 10 days. They cannot allow the sanctioned party to move, trade, or transfer the funds.

Question 25: What does FATF's 'Travel Rule' Recommendation 16 require of Virtual Asset Service Providers (VASPs)?

VASPs must report all cross-border transfers to the IMF
VASPs must use licensed courier services for hardware wallet deliveries
VASPs must verify that customers have not traveled to sanctioned countries
VASPs must collect and share originator and beneficiary information for transfers above $1,000 (Correct answer)

Correct answer: VASPs must collect and share originator and beneficiary information for transfers above $1,000

FATF Recommendation 16 requires VASPs to obtain, hold, and transmit originator and beneficiary information with transfers of $1,000 or more to combat money laundering.

Question 26: What is 'chain reorganization' (reorg) in a blockchain?

When the network switches to a longer competing chain, reversing recent blocks (Correct answer)
A process to compact old blockchain data
A governance vote to change block ordering rules
A scheduled upgrade that reorders node priorities

Correct answer: When the network switches to a longer competing chain, reversing recent blocks

A reorg occurs when nodes discover a longer valid chain and replace their current tip, rolling back recent transactions — deeper reorgs are exponentially less likely over time.

Question 27: A developer is creating a new cryptocurrency and needs to choose a hashing algorithm. They are deciding between SHA-256 and Keccak-256. Which major cryptocurrency is primarily associated with Keccak-256?

Bitcoin
Litecoin
Ethereum (Correct answer)
Dogecoin

Correct answer: Ethereum

Ethereum uses Keccak-256 as its primary hashing algorithm, which is a member of the SHA-3 family. [7, 14] Bitcoin famously uses the SHA-256 algorithm. [1, 27] Litecoin and Dogecoin both use the Scrypt algorithm. [16]

Question 28: What is the purpose of an Initial Coin Offering (ICO)?

To allow existing holders to burn their tokens for rewards
To raise capital for a new cryptocurrency project by selling tokens to investors (Correct answer)
To merge two separate blockchain networks
To officially launch a coin on a major centralized exchange

Correct answer: To raise capital for a new cryptocurrency project by selling tokens to investors

An ICO is a fundraising method where a new cryptocurrency project sells its tokens to early investors to raise development capital, similar to an IPO in traditional finance.

Question 29: What is a 'watch-only' wallet?

A wallet containing only public keys, used to monitor balances without spending ability (Correct answer)
A wallet restricted to read-only exchanges
A wallet that alerts the user when transactions occur
A wallet that only stores stablecoins

Correct answer: A wallet containing only public keys, used to monitor balances without spending ability

A watch-only wallet holds public addresses or public keys, allowing balance and transaction monitoring without exposing private keys.

Question 30: In public-key cryptography, which key is used to create a digital signature, and which key is used to verify it?

Public key to create, private key to verify.
The same secret key is used for both creation and verification.
A session key to create, a master key to verify.
Private key to create, public key to verify. (Correct answer)

Correct answer: Private key to create, public key to verify.

A digital signature is created by using the sender's private key to encrypt a hash of the message or transaction data. The recipient, or anyone on the network, can then use the sender's publicly available key to decrypt the signature and verify that it matches the transaction data, confirming authenticity and integrity without revealing the private key.

Question 31: Which Ethereum token standard is most commonly used for NFTs?

ERC-20
ERC-1400
ERC-777
ERC-721 (Correct answer)

Correct answer: ERC-721

ERC-721 is the standard that introduced non-fungible tokens on Ethereum, giving each token a unique identifier that distinguishes it from all other tokens.

Question 32: Why is it important to verify a hardware wallet's firmware integrity before use?

To confirm the firmware has not been tampered with, which could allow key extraction (Correct answer)
To activate the warranty
To synchronize the device with the latest blockchain state
To ensure the device supports the latest cryptocurrencies

Correct answer: To confirm the firmware has not been tampered with, which could allow key extraction

Compromised firmware could silently exfiltrate private keys or modify transaction details, so verifying cryptographic signatures on firmware prevents supply-chain attacks.

Question 33: What is the 'nothing-at-stake' problem in early proof-of-stake designs?

Validators could vote on multiple competing forks at no cost, undermining consensus (Correct answer)
Block proposers could propose empty blocks to collect the base fee without effort
Validators earn rewards even when they are offline, disincentivizing participation
Nodes with no stake can still read the blockchain, creating privacy risks

Correct answer: Validators could vote on multiple competing forks at no cost, undermining consensus

Unlike PoW where mining one fork means wasting hash rate on another, early PoS validators had no computational cost to vote on every fork simultaneously, undermining security.

Question 34: In Ethereum's proof-of-stake, what is an 'epoch'?

The waiting period before staked ETH can be withdrawn
A period of 32 slots used to organize validator duties and finalization checkpoints (Correct answer)
The time window during which slashing evidence must be submitted
A single slot in which one validator proposes a block

Correct answer: A period of 32 slots used to organize validator duties and finalization checkpoints

An epoch consists of 32 slots (approximately 6.4 minutes total), after which the beacon chain processes validator shuffling and finalization.

Question 35: An analyst is using on-chain analysis to gauge market sentiment. They observe a sustained, significant increase in the flow of a specific cryptocurrency from personal wallets to centralized exchange wallets. How is this metric typically interpreted?

As a sign of decreasing network activity and adoption.
As a bullish signal, indicating users are preparing to stake their assets.
As a neutral signal, indicating routine wallet maintenance.
As a bearish signal, indicating an increased potential for selling pressure. (Correct answer)

Correct answer: As a bearish signal, indicating an increased potential for selling pressure.

On-chain analysis involves examining blockchain transaction data for insights. A large and sustained flow of assets from private wallets to exchanges (exchange inflow) is generally considered a bearish indicator. It suggests that holders are moving their assets to a venue where they can be easily sold, thus increasing the available supply on the market and signaling a potential increase in selling pressure.

Question 36: What is the risk of generating a seed phrase on an internet-connected device at setup?

Malware or keyloggers could capture the seed phrase during generation (Correct answer)
The seed may not meet BIP39 entropy standards
The blockchain requires online validation of new seed phrases
Internet-generated seeds expire after 90 days for security

Correct answer: Malware or keyloggers could capture the seed phrase during generation

Any malware present during seed generation can silently record the phrase, giving attackers permanent access to the wallet without any further interaction.

Question 37: In Bitcoin mining, what is the purpose of the 'nonce'?

To vary the block header input so miners can find a valid hash (Correct answer)
To store transaction data in the block
To sign transactions cryptographically
To identify the miner's wallet address

Correct answer: To vary the block header input so miners can find a valid hash

The nonce is a 32-bit number that miners increment repeatedly to produce a block hash that meets the network's difficulty target.

Question 38: What does 'deterministic' mean when describing a cryptographic hash function?

The function uses a random seed to vary output
The output length varies based on input
The same input always produces the same output (Correct answer)
The function can be reversed with the same algorithm

Correct answer: The same input always produces the same output

Determinism means identical inputs always yield identical hash outputs, which is essential for consensus across blockchain nodes.

Question 39: What is the significance of 6 confirmations in Bitcoin?

It is the threshold at which a transaction is considered practically irreversible (Correct answer)
It represents the block where mining reward halves
It is the number of nodes required to validate a transaction
It is the number of signatures required in a multisig wallet

Correct answer: It is the threshold at which a transaction is considered practically irreversible

Six confirmations means six blocks have been added on top of the block containing a transaction, making a double-spend attack statistically impractical.

Question 40: What is a 'dusting attack' targeting cryptocurrency wallets?

Attacking a wallet's encryption with small computational increments
Sending tiny amounts of crypto to wallets in order to link addresses and de-anonymize owners (Correct answer)
Sending spam transactions to clog the mempool
Forcing a wallet to generate dust UTXOs below the fee threshold

Correct answer: Sending tiny amounts of crypto to wallets in order to link addresses and de-anonymize owners

Attackers send minuscule amounts (dust) to many addresses and then analyze how those funds move to cluster addresses and identify wallet owners.

Question 41: What is a Virtual Asset Service Provider (VASP) according to FATF?

Any business that exchanges, transfers, or safeguards virtual assets for others (Correct answer)
A licensed bank offering crypto custody
A government agency overseeing digital currencies
A company providing blockchain cloud computing services

Correct answer: Any business that exchanges, transfers, or safeguards virtual assets for others

FATF defines VASPs broadly to include exchanges, wallet providers, and any entity conducting financial activities involving virtual assets on behalf of others.

Question 42: What was the outcome of the FTX collapse regarding crypto regulation in the US?

FinCEN reduced AML requirements to attract crypto businesses back to the US
It intensified calls for stronger regulation and led to increased enforcement actions (Correct answer)
The SEC declared all crypto exchanges exempt from securities laws
Congress immediately passed a comprehensive crypto regulatory framework

Correct answer: It intensified calls for stronger regulation and led to increased enforcement actions

FTX's $8 billion fraud accelerated congressional and regulatory focus on crypto oversight, leading to more enforcement actions and regulatory proposals.

Question 43: What does it mean for an encryption scheme to be 'semantically secure'?

The scheme uses natural language processing to enhance security
An attacker cannot learn any partial information about the plaintext from the ciphertext (Correct answer)
The ciphertext is always shorter than the plaintext
The encryption algorithm is resistant to semantic (meaning-based) analysis

Correct answer: An attacker cannot learn any partial information about the plaintext from the ciphertext

Semantic security (IND-CPA) means a computationally bounded attacker gains no information about the plaintext by observing the ciphertext.

Question 44: What is the meaning of UTXO?

Unspent Transaction Output (Correct answer)
United Transaction Office
Union of Texas Operations
United Texan Xerox Organization

Correct answer: Unspent Transaction Output

UTXO stands for Unspent Transaction Output, a fundamental concept in Bitcoin and other cryptocurrencies. A UTXO represents a discrete amount of cryptocurrency that has been received in a transaction but has not yet been spent. When you spend Bitcoin, you are essentially consuming one or more UTXOs and creating new UTXOs as change and payment to the recipient.

Question 45: What problem does the Byzantine Generals Problem model in distributed blockchain networks?

How to select a leader node for block production fairly
How to synchronize clocks across geographically distributed nodes
How to compress large blocks across slow network links
How nodes can reach consensus when some participants may be malicious or faulty (Correct answer)

Correct answer: How nodes can reach consensus when some participants may be malicious or faulty

The Byzantine Generals Problem describes the challenge of achieving reliable consensus when some participants may send conflicting or dishonest messages.

Question 46: What is the primary purpose of metadata in an NFT?

To record every transaction history permanently on-chain
To set the gas fee for future transfers
To describe the properties and attributes of the NFT such as image URL and traits (Correct answer)
To store the private key of the owner

Correct answer: To describe the properties and attributes of the NFT such as image URL and traits

NFT metadata contains descriptive information about the token — including the name, description, image URL, and traits — that defines what the NFT represents.

Question 47: What is the purpose of the 'difficulty adjustment' mechanism in Bitcoin?

To keep the average block time near 10 minutes regardless of total hash rate (Correct answer)
To reduce transaction fees during periods of network congestion
To penalize mining pools that find blocks too quickly
To increase block size when block production slows below target

Correct answer: To keep the average block time near 10 minutes regardless of total hash rate

Bitcoin recalibrates mining difficulty every 2,016 blocks so that blocks are produced approximately every 10 minutes even as hash rate fluctuates.

Question 48: What is a '51% attack' in cryptocurrency networks?

A smart contract exploit affecting 51% of token holders
When a single entity controls more than half of the network's mining hash rate (Correct answer)
A phishing attack targeting 51% of exchange users
A regulatory action freezing 51% of an exchange's assets

Correct answer: When a single entity controls more than half of the network's mining hash rate

A 51% attack occurs when one entity controls the majority of mining power, allowing them to double-spend coins or reverse transactions.

Question 49: What is the recommended approach when a hardware wallet displays an 'unverified' address during a receive operation?

Always confirm the address on the hardware wallet's own trusted screen before sharing it (Correct answer)
Reset the hardware wallet and regenerate the address
Proceed normally; the warning is cosmetic
Contact the wallet manufacturer to whitelist the address

Correct answer: Always confirm the address on the hardware wallet's own trusted screen before sharing it

Always verify addresses on the hardware wallet's built-in display to ensure malware on the host computer has not substituted a different, attacker-controlled address.

Question 50: Which of the following correctly describes the difference between confusion and diffusion in block ciphers?

Confusion obscures the relationship between key and ciphertext; diffusion spreads plaintext influence across the ciphertext (Correct answer)
Confusion uses XOR operations; diffusion uses modular arithmetic
Confusion spreads plaintext bits; diffusion substitutes bits using a key
Confusion applies to stream ciphers only; diffusion applies to block ciphers only

Correct answer: Confusion obscures the relationship between key and ciphertext; diffusion spreads plaintext influence across the ciphertext

Shannon defined confusion (obscuring key-ciphertext relationships, via substitution) and diffusion (spreading plaintext influence, via permutation) as the two core principles of secure ciphers.

Cryptocurrency Knowledge Test

The Cryptocurrency Knowledge Test exam validates essential knowledge and skills required for certification or licensure in this field.

Questions

60 min

Time Limit

70%

To Pass

Checking for saved progress...

Exam Rules

You can skip questions and return to them later
Flag questions for review before submitting
No feedback shown until you submit the entire exam
Unanswered questions count as wrong — answer everything
10 pretest questions are mixed in and don't affect your score
Timer auto-submits when time runs out
Your progress is auto-saved every 30 seconds