X. Brian Zhang

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In secure group communications, users of a group share a common group key. A key server sends the group key to authorized new users as well as performs group rekeying for group users whenever the key changes. In this paper, we investigate scalability issues of reliable group rekeying, and provide a performance analysis of our group key management system(More)
We present the design and specification of a protocol for scalable and reliable group rekeying together with performance evaluation results. The protocol is based upon the use of key trees for secure groups and periodic batch rekeying. At the beginning of each rekey interval, the key server sends a rekey message to all users consisting of encrypted new keys(More)
In secure group communications, there are both rekey and data traffic. We propose to use application-layer multicast to support concurrent rekey and data transport. Rekey traffic is bursty and requires fast delivery. It is desired to reduce rekey bandwidth overhead as much as possible since it competes for bandwidth with data traffic. Towards this goal, we(More)
The trees, respectively unicyclic graphs, on n vertices with the smallest Laplacian permanent are studied. In this paper, by edge-grafting transformations, the n-vertex trees of given bipartition having the second and third smallest Laplacian permanent are identified. Similarly, the n-vertex bipartite unicyclic graphs of given bipartition having the first,(More)
Dear Editor, Programmed cell death has an essential role in development and homeostasis of mammalians. Fas-associated death domain (FADD) interacts with the death domain of receptors, leading to the activation of caspase-8, which subsequently activates several downstream caspases and finally executes apoptosis. 1 Ablation of Caspase-8 or Fadd resulted in(More)
OBJECTIVE The aim of this study was to compare the mandibular position when speaking with the intercuspal position and to check the stability of phonetics when determining the horizontal jaw relation in healthy adults. METHODS A total of 19 healthy volunteers were recruited. Seven Chinese letters, namely, /xi/, /er/, /yi/, /ci/, /mi/, /ni/, and /ri/, were(More)
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