• Implemented an AES-encrypted P2P instant messenger with HMAC authentication.
• Implemented a port scanner and a port scanner detector, which can detect a scanner if a single machine attempted to connect to 30 or more ports within a 5 second window.
• Intercepted Tor traffic package, implemented a system using machine learning techniques to determine the most likely website visited by the Tor client using the feature of the packages with an accuracy of 73%.