Question 1
4 marks
Peer-to-peer network characteristics and cryptographic entropy sources
- Networks
- Computer organisation
(a)
2 marks
- Identify two structural characteristics of a peer-to-peer (P2P) network:
- 1) Decentralized node architecture: In a P2P network, there is no centralized supervisory server; every participating host (peer) operates concurrently as both a client and a server (servent), sharing equal responsibility for transaction forwarding.
- 2) Fault tolerance and high scalability: The absence of a central coordination node eliminates single points of failure and bandwidth bottlenecks; the network organically expands processing and storage capacity as additional nodes join the distributed mesh.
Mentor tip
Identify architectural attributes (decentralized topology, simultaneous client/server roles, lack of a central single point of failure) rather than file-sharing applications.
(b)
2 marks
- Identify two physical or computational sources of entropy used in generating cryptographic keys:
- 1) Physical environmental noise: Hardware thermal variations, radioactive decay intervals, atmospheric radio noise, and acoustic room fluctuations captured by hardware Random Number Generators (TRNGs).
- 2) User and hardware interaction jitter: Minute variations in human mouse movements, keyboard inter-stroke latency intervals, and spinning disk drive head timing jitter.
Mentor tip
Provide concrete physical sources (atmospheric radio noise, thermal noise, radioactive decay) or human input timing jitter rather than stating generic 'randomness'.
