NETWORK TRAFFIC ANOMALY-DETECTION FRAMEWORK USING GPUS by Meera Ramesh Network security has been very crucial for the software industry. Deep packet inspection (DPI) is one of the widely used approaches in enforcing network security. Due to the high volume of network traffic, it is challenging to achieve high performance for DPI in real time. In this thesis, a new DPI framework is presented that accelerates packet header checking and payload inspection on graphics processing units (GPUs). Various optimizations were applied to GPU-version packet inspection, such as thread-level and block-level packet assignment, warp divergence elimination, and memory transfer optimization using pinned memory and shared memory. The performance of the pattern-matching algorithms used for DPI was analyzed by using an assorted set of characteristics such as pipeline stalls, shared memory efficiency, warp efficiency, issue slot utilization, and cache hits. The extensive characterization of the algorithms on the GPU architecture and the performance comparison among parallel pattern-matching algorithms on both the GPU and the CPU are the unique contributions of this thesis. Among the GPU-version algorithms, the Aho-Corasick algorithm and the Wu-Manber algorithm outperformed the Rabin-Karp algorithm because the Aho-Corasick and the Wu-Manber algorithms were executed only once for multiple signatures by using the tables generated before the searching phase was begun. According to my evaluation on a NVIDIA K80 GPU, the GPU-accelerated packet processing achieved at least 60 times better performance than CPU-version processing. ACKNOWLEDGMENTS It is with immense gratitude that I acknowledge the support of my advisor Dr. Hyeran Jeon throughout the thesis. Prof. Hyeran is one of the best Professors I've met and I've learned many things from her, the most important quality I cultivated because of her is patience. I would also like to thank my co-advisor Dr. Younghee Park for monitoring the progress of the project and for providing me good ideas to solve certain issues I had faced. I am also very thankful to Dr. Xiao Su for being a part of the committee and for providing her advice on the future scope of the thesis. I am indebted to my parents and my brother for instilling confidence in me. I'm thankful to my in-laws for their constant support and motivation. I'm also thankful to my friend Sindhuja, who gave her ear to my problems. This thesis would have remained a dream had it not been for the support from my husband Karthik, and I owe my deepest gratitude to him. v TABLE OF CONTENTS List of Tables .