CBSE - Certified Blockchain Security Expert Node and Network Security Questions and Answers

Question 1

A blockchain network administrator is hardening a new full node to minimize its attack surface.
Which of the following is the MOST critical first step to protect the node from known software vulnerabilities?

Accepted Answer

Ensuring the blockchain client software and operating system are fully patched and up to date.

Answer

Implementing a host-based intrusion detection system (HIDS).

Answer

Configuring strict role-based access control (RBAC) for administrative access.

Answer

Encrypting the blockchain data at rest using AES-256.

Question 2

In a Sybil attack against a proof-of-stake blockchain, what is the primary resource an attacker leverages to gain disproportionate influence over the network?

Accepted Answer

Control over a large amount of the network's staked cryptocurrency.

Answer

A large number of IP addresses to create seemingly distinct nodes.

Answer

Significant computational power to solve complex cryptographic puzzles.

Answer

Exploiting a zero-day vulnerability in the node's client software.

Question 3

A security analyst observes that a specific mining node has been isolated from the main network. The node's peer connections are all being routed to a set of malicious nodes controlled by an attacker. The victim node is being fed an alternate, fabricated version of the blockchain, causing it to waste its computational resources on an orphaned chain. What type of attack is being described?

Accepted Answer

An Eclipse Attack

Answer

A 51% Attack

Answer

A DDoS Attack

Answer

A Routing Attack

Question 4

Which of the following is a primary defense mechanism at the network layer to mitigate the risk of an Eclipse attack on a blockchain node?

Accepted Answer

Increasing peer diversity by connecting to nodes across various IP addresses and autonomous systems (ASNs).

Answer

Requiring high transaction fees to prevent spam.

Answer

Implementing multi-signature wallets for all transactions.

Answer

Using a hardware security module (HSM) to store private keys.

Question 5

A public blockchain network is experiencing a volumetric Distributed Denial-of-Service (DDoS) attack where nodes are being flooded with an overwhelming amount of transaction and peer discovery requests, exhausting their bandwidth. Which technique would be most effective in mitigating this type of attack?

Accepted Answer

Implementing rate limiting on API endpoints and filtering traffic with a Web Application Firewall (WAF) or similar service.

Answer

Auditing smart contracts for reentrancy vulnerabilities.

Answer

Increasing the block size limit of the blockchain.

Answer

Mandating Know Your Customer (KYC) for all node operators.

Question 6

What is the primary security goal of encrypting communication channels between blockchain nodes using protocols like TLS?

Accepted Answer

To maintain the confidentiality and integrity of peer-to-peer messages against eavesdropping and man-in-the-middle attacks.

Answer

To ensure the immutability of the blockchain ledger.

Answer

To prevent Sybil attacks by validating node identities.

Answer

To increase the speed of transaction propagation across the network.

A blockchain network administrator is hardening a new full node to minimize its attack surface.Which of the following is the MOST critical first step to protect the node from known software vulnerabilities?

A blockchain network administrator is hardening a new full node to minimize its attack surface.
Which of the following is the MOST critical first step to protect the node from known software vulnerabilities?