We propose an efficient multicast source authentication protocol called efficient multi-tree-chains scheme （EMTC）, which shows more loss resistibility, less communication cost, and no delay at receivers. The EMTC scheme is based on combination of single Chain scheme and Hash Tree Chains scheme, and integrates the advantages of both. In this scheme, stream is firstly divided into blocks with n packets, and each block consists of m clusters, everyone of which contains a tree of packets. All clusters are chained together. Through EMTC, packets of one cluster can be authenticated by any packet of the previous cluster. Compared to other multicast authentication protocols, the proposed scheme has the following advantages： ① dramatically improves the resistance to burst packets loss; ② low computation and communication overhead; ③ imposes low delay on the sender side and no delay on the receiver side.
从讨论非对称二分查找树的平衡问题出发,给出了一种通用的平衡权函数构造方法,解决了Waldvogel等在算法优化过程中提出的启发式平衡权函数构造问题,优化了非对称二分查找树平衡算法,使得CHT(col-lection of hash tables)算法很容易扩展到128 bit的IPv6地址.实验表明,该算法与Waldvogel等在特殊情况下给出的推测结果基本符合,能很好地适应IP前缀分布的变化,具有很好的适应性和可扩展性.
