Mixed Deck — All CBE Topics Flashcards

Which of the following network-level attacks on a blockchain node involves isolating it from the rest of the honest network and connecting it exclusively to attacker-controlled nodes, potentially leading to double-spending or selfish mining?

Answer: Eclipse Attack

An eclipse attack is a network-level attack where an adversary monopolizes all of a victim node's connections, isolating it from legitimate peers. This allows the attacker to feed the node false information about the blockchain's state, which can be exploited for double-spending or to disrupt consensus.

What is a key benefit of dApps over traditional apps?

Answer: Censorship resistance

A key benefit of dApps over traditional applications is their censorship resistance. Because dApps operate on decentralized blockchain networks, they are not controlled by a single entity and cannot be easily shut down, altered, or censored by governments or corporations. This ensures continuous availability and user access.

An enterprise choosing to implement a private blockchain instead of a public one gains enhanced performance and data confidentiality at the expense of which key blockchain principle?

Answer: Decentralization

Private blockchains are controlled by a single entity, making them centralized. This centralization allows for higher performance and privacy controls but sacrifices the core benefit of decentralization, which provides the trustlessness and censorship resistance found in public networks.

What is the fundamental principle behind system architecture in the context of Certified Blockchain Expert?

Answer: Ensuring reliability, security, and optimal performance

System Architecture in Certified Blockchain Expert fundamentally aims to ensure system reliability, security, and optimal performance.

What is gas in the context of smart contracts?

Answer: Execution fee

In the context of smart contracts, 'gas' refers to the execution fee required to perform operations on the Ethereum blockchain. It is a unit that measures the computational effort needed to execute transactions or smart contract functions. Users pay gas fees in Ether to compensate miners for the resources consumed in processing and validating these operations.

What is the fundamental role of the backend in a typical Decentralized Application (DApp) architecture?

Answer: To run on a decentralized peer-to-peer network, typically consisting of smart contracts.

The defining characteristic of a DApp is that its backend logic runs on a decentralized network, not a central server. This backend is primarily composed of smart contracts that execute on the blockchain, ensuring the application is censorship-resistant and operates in a trustless manner.

What is a smart contract in blockchain technology?

Answer: Self-executing program

A smart contract is a self-executing program stored directly on a blockchain. It automatically executes predefined actions and terms of an agreement when specific conditions are met, without the need for intermediaries. This ensures transparency, immutability, and trustless execution of agreements.

What is the primary function of a cryptographic hash function in a blockchain?

Answer: To provide a unique, fixed-size digital fingerprint for data, ensuring its integrity and linking blocks together.

Cryptographic hash functions are fundamental to blockchain's security and immutability. They take an input of any size and produce a unique, fixed-length output (the hash). Any change to the input data results in a completely different hash, which is how data integrity is ensured. Hashes are also used to chain blocks together, creating a tamper-evident ledger.

In the context of blockchain platforms, the term 'permissionless' primarily implies that:

Answer: anyone can join the network, participate in consensus, and view the ledger without needing approval.

'Permissionless' directly refers to the lack of a gatekeeper for participating in the network's core functions. On a public, permissionless blockchain, any individual can connect a node, view the public ledger, submit transactions, and attempt to participate in the consensus mechanism without seeking approval from a central authority.

What is a 'constitutional DAO' governance approach?

Answer: A DAO with a written charter defining immutable rules, member rights, and governance processes

A constitutional DAO codifies its founding principles and governance rules in a document (often on-chain), providing stability and clarity for members.

What is a key benefit of dApps over traditional apps?

Answer: Censorship resistance

A key benefit of dApps over traditional applications is their censorship resistance. Because dApps operate on decentralized blockchain networks, they are not controlled by a single entity and cannot be easily shut down, altered, or censored by governments or corporations. This ensures continuous availability and user access.

What is a 'state channel' and how does it improve blockchain scalability?

Answer: A private off-chain communication channel where parties exchange signed state updates, settling only the final state on-chain

State channels allow parties to conduct many interactions off-chain by exchanging cryptographically signed messages, posting only the final outcome to the blockchain.

What is an Initial DEX Offering (IDO) and how does it differ from an ICO?

Answer: An IDO is a token launch conducted on a decentralized exchange providing immediate on-chain liquidity, unlike ICOs which use centralized platforms

An IDO launches tokens directly on a decentralized exchange, providing immediate trading liquidity from day one and eliminating centralized intermediaries, unlike ICOs which rely on centralized platforms and may have delayed exchange listings.

A user wants to authorize a cryptocurrency transaction on a blockchain network. Which of the following cryptographic tools allows the user to prove ownership of the funds and authorize the transfer without revealing their secret key?

Answer: Digital Signature

A digital signature is created using the sender's private key and the transaction data. Others on the network can then use the sender's public key to verify that the signature is authentic and that the transaction has not been altered, thus proving ownership and authorizing the transaction without exposing the private key.

Which programming language is primarily used to write Ethereum smart contracts?

Answer: Solidity

Solidity is the primary high-level, contract-oriented programming language specifically developed for writing smart contracts on the Ethereum blockchain. It is syntactically similar to JavaScript and is the most widely used language for creating decentralized applications (dApps) and their underlying logic within the Ethereum ecosystem.

What is Ethereum's EIP-4844 (Proto-Danksharding) designed to improve?

Answer: Reducing the cost of posting rollup data to Ethereum by introducing temporary 'blob' data storage

EIP-4844 introduces blob-carrying transactions that provide cheap, temporary data storage specifically for rollups, dramatically reducing L2 transaction costs.

What distinguishes a security token from a utility token under US securities regulations?

Answer: Security tokens represent an investment with an expectation of profit derived from others' efforts, making them subject to SEC regulations

Security tokens pass the Howey Test by representing an investment of money in a common enterprise with an expectation of profits from others' efforts, triggering full SEC regulatory oversight.

Which approach is recommended for implementing system architecture changes?

Answer: Following a structured change management process with testing

A structured change management process with proper testing minimizes risk and ensures successful implementation.

How should you document system architecture configurations?

Answer: Maintain up-to-date documentation in a centralized, accessible location

Centralized, accessible, and current documentation is essential for troubleshooting, disaster recovery, and knowledge sharing.

Which of the following best defines a public blockchain?

Answer: Permissionless and open

A public blockchain is characterized by being permissionless and open, meaning anyone can join the network, participate in validating transactions, and read the ledger without needing special authorization. This contrasts with private or consortium blockchains, which restrict access and participation. Bitcoin and Ethereum are prime examples of public blockchains.