Peer isolation
In an eclipse attack, an adversary attempts to control a node's peer connections and restrict its view of the network. Diverse peers, address management, connection rotation and protected network infrastructure raise the cost of isolation.
Majority hashpower
Sustained majority hashpower can censor transactions or reorganise recent valid history. It cannot create signatures for other users, spend their coins without authorization or make an invalid block pass full-node validation.
Denial of service and resilience
Attackers can consume bandwidth, memory or CPU with hostile traffic. Bitcoin Core uses resource limits, validation ordering, peer scoring and eviction strategies, while operators add firewalls, monitoring and recovery planning.
Visual recap
Layered network defence
No single mechanism solves every threat; independent validation remains the final boundary.
Hostile traffic
Peer diversity
Resource controls
Consensus validation
Recovery and relay
Key takeaways
- Peer diversity reduces isolation risk.
- Hashpower cannot override signature or supply rules.
- Resource controls limit denial-of-service impact.
- Monitoring and independent validation remain essential.
Lesson recap
Check what you learned
Reveal each model answer, then honestly mark whether you understood it or need another review.
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Recall
What can a majority-hashpower attacker not do to a correctly validating node?
References
