HCAA:一种哈希冲突过度的动态解决算法

摘要

As a data structure for rapid lookup, hash table is widely used in network security applications, such as firewalls etc. However, attackers may use some approaches to launch hash attacks towards these aplications to let them stop responding* so that some malicious data flows can escape from management and control of network security applications. The paper introduces a dynamic hash collision excessive solution algorithm named HCAA (Hash Collision Acceptable Algorithm). When hash collisions are too concentrated, the algorithm handles collision data flows by dynamically applying for hash table and making use of different hash functions to confine collisions within an acceptable scope. Experiment results validate that, compared to existing methods, HCAA can obtain more balanced hash effect with less usage of hash table items, so that faster hash operation can be achieved upon data flows.%HASH表作为一种快速查询的数据结构,在防火墙等网络安全应用中得到了广泛的应用.然而,攻击者可能通过一些手段对这些应用发动HASH攻击使其失去响应,从而使某些恶意的数据流能够逃脱网络安全应用的管理和控制.提出一种动态的哈希冲突过度的解决算法—HCAA( Hash Collision-Acceptable Algorithm)算法,该算法在哈希冲突过于集中时通过动态申请HASH表并使用不同哈希函数来对冲突数据流进行处理,使冲突在可接受的范围内.实验结果表明,与已有方法相比,HCAA算法能在使用更少HASH表项的情况下获得更均衡的HASH效果,从而能对数据流进行更快的HASH操作.