Improving the Resilience of Computing Infrastructures against Zero Day Attacks through Quantitative Threat Modeling and Network Hardening

今天的计算基础设施在企业、政府或军事组织以及电网等关键基础设施中发挥着神经系统的作用。然而，计算基础设施安全漏洞的规模和严重性继续以越来越大的速度增长，这从许多备受瞩目的安全事件中可见一斑，例如最近由Mirai僵尸网络导致的大规模DDoS攻击，以及2015年乌克兰电网遭受的网络物理攻击，导致超过23万居民蒙在鼓里。所谓的零日攻击利用以前未知或未打补丁的漏洞，通常是此类安全事件的幕后黑手(例如，Stuxnet使用四个不同的零日漏洞来攻击工业控制系统)。因此，超越传统的防御方法来评估和提高计算基础设施对潜在零日攻击的弹性是重要的。大多数现有的威胁建模、安全指标和网络加固解决方案都基于有关现有漏洞的已知事实，不适用于零日攻击。在这样的背景下，拟议的研究计划旨在开发一系列用于建模、测量和缓解零日攻击的新技术，并将这些技术应用于任务关键型计算基础设施，如数据中心、企业网络和关键基础设施，以提高它们对零日攻击的弹性。

Today's computing infrastructures are playing the role of nerve systems in enterprises, governmental or military organizations, and critical infrastructures, such as power grids. However, the scale and severity of security breaches in computing infrastructures have continued to grow at an ever-increasing pace, which is evidenced by many high profile security incidents, such as the recent large scale DDoS attacks caused by the Mirai Botnet and the cyber-physical attack on Ukraine power grid in 2015 which left more than 230,000 residents in the dark. The so-called zero day attacks, which exploit previously unknown or unpatched vulnerabilities, are usually behind such security incidents (e.g., Stuxnet employs four different zero day vulnerabilities to target an industrial control system). Therefore, going beyond traditional defense approaches to evaluate and improve the resilience of computing infrastructures against potential zero day attacks is important. Most existing solutions for threat modeling, security metrics, and network hardening are based on known facts about existing vulnerabilities and are not applicable to zero day attacks. In such a context, the proposed research program aims to develop a series of novel techniques for modeling, measuring, and mitigating zero day attacks, and to apply such techniques to mission critical computing infrastructures, such as data centers, enterprise networks, and critical infrastructures, in order to improve their resilience against zero day attacks.