9. P2P Security Issues
Peer-to-peer systems distribute storage and lookup across many nodes instead of relying on central servers.
9.1 Why P2P Matters in Security
P2P systems raise questions about:
- trust,
- routing integrity,
- anonymity,
- resilience,
- censorship resistance,
- and abuse.
9.2 Structured P2P Networks
Structured P2P systems use disciplined overlay routing, often based on distributed hash tables (DHTs).
Examples:
- Chord
- Pastry
- Kademlia
Security issues
- malicious nodes in routing tables,
- incorrect lookups,
- poisoning,
- Sybil-like positioning problems,
- anonymity leakage,
- and content integrity concerns.
9.3 BitTorrent and Abuse Questions
BitTorrent is a prominent P2P protocol for file sharing.
Security discussions include:
- tracker trust,
- metadata leakage,
- peer behavior,
- abuse of distributed sharing,
- and “will I be caught?” style operational visibility questions.
9.4 Small-World / Unstructured P2P
Unstructured or small-world overlays rely more on ad hoc or human-established relationships.
Freenet
Freenet is an important example focused on anonymous information distribution.
Security themes
- routing manipulation,
- caching behavior,
- anonymity limits,
- trust-path assumptions,
-
and exploitation of overlay logic.