Distributed Denial-of-Service (DDoS) attack remains a serious problem on the Internet today, as it takes advantage of the lack of authenticity in the IP protocol, destination oriented routing, and stateless nature of the Internet. Among various DDoS attacks, the TCP SYN flooding [1] is the most commonly-used one. It exploits TCP’s three-way handshake mechanism and TCP’s limitation in maintainin...

Brand and Zaaropulo BZ83] introduced the model of communicating nite-state machines to represent a distributed system connected with FIFO channels. Several diierent communication protocols can be speciied with this simple model. In this paper we address the problem of automatically validating protocols by verifying properties such as well-formedness and absence of deadlock. Our method is based ...

Transmission control protocol (TCP) employs acknowledgement (TCP-ACK) for every transmitted packets to ensure reliable transmission. As a result, it sends the next window after receiving TCP-ACK packet of previous window. This means that earlier arrives, faster TCP transmission and better performances. To do so, there should be special treatment fasten paper proposes collision probability reduc...

We study the maximum information gain that an adversary may obtain through hacking without being detected. Consider a dynamical process observed by sensor transmits local estimate of system state to remote estimator according some reference transmission policy across packet-dropping wireless channel equipped with acknowledgments (ACK). An overhears transmissions and proactively hijacks reprogra...

I am interested in solving system security problems via program analysis techniques. More speci€cally, I have developed fundamental primitives for the investigation of advanced cyber-aŠacks and the analysis and prevention of everevolving malicious programs and payloads across multiple platforms. In particular, my research focuses on building systems to solve three prominent problems in system s...

In this paper, we focus on the performance of TCP splitting in satellite-terrestrial hybrid networks. By simulation we show that long-time link outage has great negative impact on TCP throughput. To solve the problem, an ACK reservation scheme is proposed to speed up TCP recovery from link outage and analytical estimate of a key parameter of the scheme is provided for achieving high end-to-end ...

The IEEE has recently released IEEE 802.15.5 standard [3] to provide multi-hop mesh functions for low-rate wireless personal area networks (WPANs). In this paper, we extensively describe a link-layer reliable broadcast protocol referred to as timer-based reliable broadcast (TRB) [3] in the IEEE 802.15.5 standard. The TRB scheme exploits (1) bitmap based implicit ACK to effectively reduce the un...

It is well-known that MAC protocols for multihop wireless networks face the problems of hidden and exposed nodes due to the limited transmission range of wireless nodes. The Distributed Coordination Function (DCF) mechanism of the IEEE 802.11 standard [2] addresses the issue of hidden node problem by employing a four-way handshake of RTS-CTSDATA-ACK frames. In this exchange, the transmitter emi...

A set of low-cost sensors is deployed to infer the network topology a self-organizing wireless network. The operate in non-invasive fashion, extracting only timings data packets and acknowledgment (ACK) from all nodes meta-data also reports source node each packet, but not destination or contents packets. central processor collects sensors, goal for based solely on such information. Prior work ...