Summarizing and Searching Data in Computer Networks

, M.Sc. Thesis Sharif University of Technology Tavakoli, Mehdi (Author) ; Jafari, Amir (Supervisor) ; Kharrazi, Mehdi (Supervisor)

Abstract

Network forensic analysts employ Payload Attribution Systems (PAS) as an investigative tool. With such tool large amount of network traffic, including full packet payload, is summarized and stored. Hence an investigator could query the system for a specific string and see whether any packets transmitted previously in the network contained that specific string. Wildcards are an important type of query that allows the investigator to locate strings in the payload when only part of the string is known. In this thesis we present a new payload attribution technique, named character based bloom filter, which in addition to improving on previously proposed techniques is able to support wildcard...

Watermarking of a Fingerprint Image

, M.Sc. Thesis Sharif University of Technology Gazorpak, Maryam (Author) ; Fatemizadeh, Emadeddin (Supervisor)

Abstract

Extracting the minutia of a fingerprint image and then hiding this information in the original image in order to increase the security has been explained and implemented in this thesis. One of the methods which can embed the predetermined digital data in the image is digital watermarking. In this thesis, the host image is a fingerprint image whose minutia has been embedded in that image. Embedding can be done in two spatial and frequency domains. In this thesis, embedding is implemented by combining two domains. Embedding in the frequency domain is applied to transforming coefficients directly from the image then by spatial method the information is embedded. Actually combining DWT and LSB...

Design new Video Fingerprinting Algorithm

, M.Sc. Thesis Sharif University of Technology Tanghatari, Ehsan (Author) ; Sharifkhani, Mohammad (Supervisor)

Abstract

Digital videos is one of biggest parts of digital world. With rapid development of social networks, it is more challenging to protect media against copy right violations. Video fingerprint algorithms is one of the best tools which help detecting these violations. In this thesis, we propose two algorithms in compressed and uncompressed domains which are based on dividing videos in shots. We apply our algorithms on H264 Compression standard. In compressed domain, we use frame size in bytes in stream of video for extracting fingerprints. In Uncompressed domain, we apply multi kernel algorithm in image pyramid to extract fingerprint from videos. Results from Testing on our Dataset including 1278...