Paper review : Reliable Group Rekeying: A Performance Analysis (YZLL01)

• Goal
  To investigate the scalability issues of reliable group rekeying.

• Contribution
  The paper provides a performance analysis of keygem. The performance analyses shows the tradeoffs bwtween bandwidth requirements and rekey interval, hence provides some guideline for getting an appropriate balance. The author also present a reliable rekey transport protocol based upon the use of proactive FEC.

• Main ideas
  • All three components of a key management service need to be scalable in order for the scalability of the whole system.
  • Batch rekeying can achieve large performance gains.
  • Rekey transport has an eventually reliability and a soft real-time requirement; and the rekey transport workload has a sparseness property.

• Evaluation
  • Significance rating: 3
    This paper emphasises the importance to make each component of the key management service scalable. The performance analyses provide more opportunities to improve the overall performance. The paper also mentions the tradeoff between different factors, and the guideline is helpful for the realistic key management systems.

  • Convincing rating
    The authors heavily use the mathematical analyses in this paper for evaluating the perfomances. Anyway, some of the analyses need some assumptions.

  • Limitation
    The rekey model is still based on the key tree. Although it seems like key tree already provides a good solution for reliable group rekeying, it is still possible to find some better models, I guess.

• Conclusion
  For a well-designed rekey system, the scalability of each components and the coordination among them are critical to make the whole system work. A change in some part also needs to consider the related effects on other components.

  11/14/01