Research Interests

My research interests include Computer NetworkInternet Measurement, Constraint Solver and Network Security.


  • FUTURE NETWORK (e.g., SDN and NFV)

From: AT&T


  • NETWORK TELEMETRY

From: Cisco


  • CONSTRAINT SOLVER

why declarative design?

I conclude there are two ways of constructing a software design.
One way is to make it so simple there are obviously no deficiencies, and the other way is to make it so complicated that there are no obvious deficiencies.
– Tony Hoare [Turing Award Lecture, 1980]

why automated analysis?

The first principle is that you must not fool yourself, and you are the easiest person to fool.
– Richard P. Feynman


  • NETWORK FIREWALL

网包分类(Packet Classification) & 深度包检测(Deep Packet Inspection): 在网络转发和监控中,多域网包分类是高层路由、安全网关等多项应用中的核心技术。网包分类的本质是计算几何中的多维空间点定位问题。由于其规则的多维度(multi-dimension)、优先级(priority)和交叠性(overlapping)等特点,网包分类算法复杂低效,始终是困扰高速网络设备的瓶颈。随着软件定义网络(SDN, Software Defined Networking)的概念和OpenFlow技术的兴起,多域网包分类在可编程网络平台上面临着更高维度和更快更新速率等新的问题。因此,结合当前最新的软硬件平台进展,研究和开发新型高性能网包分类算法,成为推广高性能网络监控设备和可编程网络平台的必由之路。此外,随着互联网应用不断增加以及应用层协议趋于复杂,传统的基于网包包头(packet header)的状态检测(stateful inspection)技术已经不能满足当前网络安全处理的需求,基于网包载荷(packet payload)的深度检测(DI, Deep Inspection)技术由此兴起,并且已经成为业务感知路由器、深度检测防火墙、网络入侵检测/防御系统(NIDS/NIPS,Network Intrusion Detection/Prevention System)以及统一威胁管理(UTM, Unified Threat Management)等设备的关键组成部分和核心技术所在。本方向深入研究深度检测技术中的模式匹配(pattern matching)问题,即如何在网流的载荷中快速高效地匹配字符串(string)或正则表达式(regular expression)特征。随着软件定义网络(SDN, Software Defined Networking)等概念的提出以及云计算的日益普及,模式匹配在可编程网络传输节点和服务节点上面临着特征复杂、规模庞大、更新快速、绿色节能等方方面面的新问题。因此,结合当前最新的软硬件平台进展,研究新型高效能的模式匹配算法,对于开发和推广高性能网络安全检测及内容感知等设备具有十分重要的意义。

From: 清华大学信息技术研究院网络安全实验室