Network & Node Security Flashcards
7 cards from real Blockchain Technology practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Network & Node Security flashcards as text
An attacker isolates a node from the honest network and feeds it a false view of the blockchain. What attack is this?
Answer: Eclipse attack
An eclipse attack monopolizes a victim node's peer connections to control all information it receives.
Which practice best mitigates eclipse attacks on a node?
Answer: Diversifying inbound/outbound peers and using anchor connections
Maintaining diverse peers and persistent anchor connections makes it harder to monopolize a node's connections.
What is the primary purpose of a node running behind a firewall exposing only the necessary P2P port?
Answer: Reduce the attack surface for remote exploitation
Limiting exposed ports reduces avenues an attacker can use to reach the node.
A full node's RPC interface is exposed to the public internet without authentication. What is the main risk?
Answer: Unauthorized commands, wallet access, or DoS
Open RPC endpoints can let attackers query data, drain wallets, or overwhelm the node.
Which transport-layer protection helps secure communication between a node and its remote RPC clients?
Answer: TLS encryption with authentication
TLS encrypts and authenticates the channel, preventing eavesdropping and tampering.
What does a Sybil attack on a peer-to-peer blockchain network involve?
Answer: Creating many fake identities to gain disproportionate influence
A Sybil attack floods the network with fake nodes to subvert peer selection or consensus signaling.
Why is keeping node software updated a critical network-security control?
Answer: Patches fix known vulnerabilities and consensus bugs
Updates close exploitable security holes and prevent chain splits from outdated consensus rules.