Yaron Koral

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—Pattern matching algorithms lie at the core of all contemporary Intrusion Detection Systems (IDS), making it intrinsic to reduce their speed and memory requirements. This paper focuses on the most popular class of pattern-matching algorithms, the Aho-Corasick–like algorithms, which are based on constructing and traversing a Deterministic Finite Automaton(More)
— One of the fundamental technique which is used today by network security tools to detect malicious activities is 'signature based' detection. Today, the performance of the security tools is dominated by the speed of the string-matching algorithms that detect these signatures. Currently these security tools do not deal with compressed traffic, which(More)
Middleboxes play a major role in contemporary networks, as forwarding packets is often not enough to meet operator demands, and other functionalities (such as security, QoS/QoE provisioning, and load balancing) are required. Traffic is usually routed through a sequence of such middleboxes, which either reside across the network or in a single, consolidated(More)
This paper takes advantage of the emerging multi-core computer architecture to design a general framework for mitigating network-based complexity attacks. In complexity attacks, an attacker carefully crafts " heavy " messages (or packets) such that each heavy message consumes substantially more resources than a normal message. Then, it sends a sufficient(More)
Early programming languages for software-defined networking (SDN) were built on top of the simple match-action paradigm offered by OpenFlow 1.0. However, emerging hardware and software switches offer much more sophisticated support for persistent state in the data plane, without involving a central controller. Nevertheless, managing stateful, distributed(More)
Current security tools, using "signature-based" detection, do not handle compressed traffic, whose market-share is constantly increasing. This paper focuses on compressed HTTP traffic. HTTP uses GZIP compression and requires some kind of decompression phase before performing a string matching. We present a novel algorithm, Aho-Corasick-based algorithm for(More)
Compressing web traffic using standard GZIP is becoming both popular and challenging due to the huge increase in wireless web devices, where bandwidth is limited. Security and other content based networking devices are required to decompress the traffic of tens of thousands concurrent connections in order to inspect the content for different signatures. The(More)
— Deep Packet Inspection (DPI) is the most time and resource consuming procedure in contemporary security tools such as Network Intrusion Detection/Prevention System (NIDS/IPS), Web Application Firewall (WAF), or Content Filtering Proxy. DPI consists of inspecting both the packet header and payload and alerting when signatures of malicious software appear(More)
A central component in all contemporary intrusion detection systems (IDSs) is their pattern matching algorithms, which are often based on constructing and traversing a deterministic finite automaton (DFA) that represents the patterns. While this approach ensures deterministic time guarantees, modern IDSs need to deal with hundreds of patterns, thus(More)