Welcome to my homepage

Thank you for visiting. I am a full-time PhD student at the Department of Computer Science, The State University of New York at Stony Brook under the supervision of Dr. Michalis Polychronakis. Currently, I am working as a visiting research fellow at Dr. Phillipa Gill’s Calipr Lab, University of Massachusetts - Amherst.

My research interest encompasses Security and Privacy, with an emphasis on anonymity networks and Internet censorship circumvention technologies. In particular, I am interested in conducting network measurements to gain insight into anonymity networks (e.g., Tor, I2P) and technologies (e.g., proxy, VPN) that are used for censorship circumvention.

Notes - Useful Bash Commands

Follows are command lines that I often use (not necessarily the best approach) while interacting with Unix shell. Find files (including files in subdirectories) whose size is larger than x k bytes (replace k with M for mega bytes). sudo find . -type f -size + xk Re-run through some tasks periodically (e.g., every 10 minutes = 10 * 60s): while true; do ...; sleep 600; done Get size (disk usage) of a file/directory: [Read More]

Notes - Add OpenVPN and SSTP VPN Connections to NetworkManager in Ubuntu 18.04 Using CLI

This note originates from an effort to find ways to automate OpenVPN and SSTP VPN connections from an Ubuntu 18.04 machine using CLI. For setting VPN connection from GUI, NetworkManager GNOME has nice third-party packages for most VPN protocols. Only follow this note if you want to setup OpenVPN or SSTP VPN connection from CLI. OpenVPN has a nice CLI tool (i.e. openvpn). However, connecting to an SSTP VPN server using CLI (e. [Read More]


Mahatma Gandhi used to say: “Live as if you were to die tomorrow. Learn as if you were to live forever.” Therefore, I always try to improve my knowledge and keep myself up to date by reading. In addition to reading, I think taking note also helps me to understand the topic, remember it longer, and easier to trace back something that I have read. Therefore, here is a list of notes of various topics that I read/learned from several sources. [Read More]

Notes - Connect to An SSTP VPN Server Using Command Line in Ubuntu

SSTP stands for Secure Socket Tunneling Protocol, developed by Microsoft. It is one of the most powerful and widely used VPN protocols. It has the ability to bypass most firewalls because it uses SSL over port 443, which is also used by the famous protocol – HTTPS. Together with OpenVPN protocol, SSTP is considered one of the “stealth-VPN” protocols. Since it is owned by Microsoft, most Windows operating systems has a built-in SSTP-client. [Read More]

Notes - Remove Broken Files (broken content, broken file name) in Ubuntu

I once wrote a python program to create text files, which only contain ASCII and UTF-8 Unicode text. Before being written to a file, every non-UTF-8 line of text is decoded to UTF-8 using this line of code: line = line.decode('utf-8', 'ignore').encode("utf-8") I noticed many suggestions on StackOverFlow to use python’s string.printable or bash’s strings command to sanitize the text. However, these functions will remove all non-ASCII characters, which includes many, many valid UTF-8 characters because ASCII is a subset of UTF-8 (reference). [Read More]

Notes - Useful Command in AWS's CLI

Follows are command lines that I often use (not necessarily the best approach) while interacting with AWS. Before starting, you will need to install the CLI. For macOS, use brew install awscli For Linux, use pip install awscli Commands list files from a public S3 bucket. If the bucket is not publicly accessible, you need to sign in and do not need the --no-sign-request flag: aws --no-sign-request s3 ls s3://<bucket>/<path> Download files from a S3 bucket: [Read More]

Notes - Docker Containers Command Lines

Follows are command lines that I often use (not necessarily the best approach) while interacting with Docker Container. Commands are correct up to Version 18.03.1. show all containers, including inactive ones: docker ps -a show images: docker images run a container from an image in interactive mode: docker run -d -it --name [nameOfContainer] [imageName:version or imageID] get into a container with a bash shell: docker exec -it [containerID] /bin/bash show images: [Read More]


PhD's Courses @ SUNY Stony Brook 2018 Spring Semester: CSE595 Semantic Web (Instructed by Dr. Paul Fodor) 2017 Fall Semester: CSE508 Network Security (Instructed by Dr. Michalis Polychronakis) 2017 Spring Semester: CSE547 Discrete Mathematics (Instructed by Dr. Anita Wasilewska) 2017 Spring Semester: CSE534 Fundamentals of Computer Networks (Instructed by Dr. Aruna Balasubramanian) 2016 Fall Semester: CSE532 Theory of Database Systems (Instructed by Dr. Fusheng Wang) 2016 Fall Semester: CSE509 System Security (Instructed by Dr. [Read More]


Lecture Notes Lecture 1: 情報教育特論0(講義計画)[PDF] Lecture 2: 情報教育特論1(概観)[PDF] Lecture 3: 大学におけるジェネリック・スキル教育の意義と課題 [PDF] Lecture 4: 情報教育特論 情報セキュリティ・情報倫理教育[PDF] Lecture 5: メディアリテラシー教育[PDF] Lecture 6: インフォメーションリテラシー[PDF] Lecture 7: ITリテラシー教育[PDF] Lecture 8: プログラミング教育 [PDF]  Lecture 9: 教室でのIT利用[PDF] Lecture 10: キャンパスの情報基盤[PDF] Homework Assignment 1 以下の情報セキュリティ e-Learning を受講し https://security-learning.nii.ac.jp/course/view.php?id=18 https://security-learning.nii.ac.jp/course/view.php?id=7&lang=ja 受講前には知らなかった事項、さらに追加されればよいと思われる事項、この e-Learning は学習したことが実践されて意味を持つがその視点からの指摘事項についてA4 版3枚程度にまとめ PDF 形式で提出すること Assignment 2 中等教育(中学,高校)での情報教育について以下を論じよ。 中学,高校で科目としてどのように設定されているかを整理せよ。 これらの科目の実施における課題を挙げよ。 また,その課題についてどのような解決方法があるか,その実現可能性を検討して意見を述べよ。 Assignment 3 従来のマスメディア(テレビ,新聞)とインターネットについてメディアリテラシーの視点からその相違と,それを教育にどのように反映させるかを議論しなさい。 [Read More]

Information System Design 1

Course Schedule [PDF] Homework Assignment 1: WBS: Work Breakdown Structure [PDF] [Submitted Version PDF] Xmind for drawing Project [Download], or Create diagrams online Real time collaboration [here] Assignment 2: PDM: Precedence Diagramming Method [PDF] [Submitted Version PDF] Assignment 3: Project Schedule - Critical Path [PDF] [Submitted Version PDF] Assignment 4: Services Computing 1 [PDF] [Submitted Version PDF] Assignment 5: Services Computing 2 [PDF] [Submitted Version PDF] Assignment 6: Services Computing 3 [PDF] [Submitted Version PDF] Past Examinations from 2009 to 2015: [PDF] [Read More]