Blockchain Security Training Network and Node Security 2

Question 1

An attacker monopolizes all of a victim node's peer connections to control its view of the network. What attack is this?

Accepted Answer

Eclipse attack

Answer

Replay attack

Answer

Dusting attack

Answer

Phishing attack

Question 2

Which practice best protects a validator node's signing keys?

Accepted Answer

Store keys in a hardware security module or remote signer

Answer

Keep keys in plaintext on the validator host

Answer

Email keys to a backup account

Answer

Hardcode keys in the client config

Question 3

What is the primary purpose of running a node behind a firewall that only exposes the P2P port?

Accepted Answer

Reduce attack surface by blocking unneeded ports

Answer

Increase block reward

Answer

Speed up transaction signing

Answer

Bypass consensus rules

Question 4

A node operator notices the RPC interface is reachable from the public internet. What is the main risk?

Accepted Answer

Unauthorized access to node management and wallet functions

Answer

Faster block propagation

Answer

Higher staking yield

Answer

Improved peer discovery

Question 5

Which DNS-related weakness can mislead a new node during initial peer discovery?

Accepted Answer

Poisoned DNS seed returning attacker-controlled peers

Answer

Slow DNS lookups only

Answer

DNS caching of valid records

Answer

Encrypted DNS queries

Question 6

Why is keeping node client software updated a security priority?

Accepted Answer

Patches fix known consensus and network vulnerabilities

Answer

It increases the block size automatically

Answer

It removes the need for a firewall

Answer

It guarantees higher rewards

Question 7

What does a Sybil attack rely on to influence a peer-to-peer network?

Accepted Answer

Creating many fake identities or nodes

Answer

Encrypting all traffic

Answer

Reducing the number of validators

Answer

Increasing gas fees