Contents

This workshop is a (mandatory!) part of the Network Security lecture held in the winter term 2015/2016. Subject of the workshop are all topics covered in the first chapter "Physical- & Link-Layer Security":

• Jamming: Attacks, Detection, Mitigation
• WiFi (IEEE 802.11): Problems, Attacks, State-of-the-art
• Cellular networks: GSM, LTE
• Cyber-physical Systems: PKES, ADS-B
• Countermeasures: Secure Location Verification, Distance Bounding

Organization

The workshop is organized in a typical computer science research conference manner. It consists of three phases:

1. Submission phase: Students submit their contributions (here: in form of essays) to the conference. Each essay must be written in a group of three students. Therefore, you need to find two peers for your group. In case you do not know any other attendees, you will have the opportunity to find a group in the lecture. Please read the submission guidlines (below) carefully!
2. Review phase: After the submission deadline (TBA) has passed, all submissions will be reviewed and rates by members of the program committee. For this workshop, the program committee consists of all authors, i.e. you. That means, that you have to read, comment, and rate three essays from other students. The submission and reviewing process is double-blind, which means that neither the authors know the reviewers, nor do the reviewers know the authors.
3. Revision phase: Once the deadline for reviews has passed, we hand out the (anonymous) reviews to the authors of the essays. The authors will then have to revise their essay based on the comments of the reviewers. After processing the reviews and updating the essays, the groups have to re-submit their works and the reviewers have to adjust their ratings.

After the third phase, we will take the best essays (according to their ratings) and publish them on the lecture's website in form of a workshop proceedings. As already mentioned in the lecture, the successful participation in this workshop (including all three phases) is mandatory and a formal prerequisit to the exam. Successful participation means that the final rating of your essay must be at least 0 (on a Likert scale).

Deadlines

Note: These deadlines are hard deadlines! Missing them results in an immediate exclusion from the workshop and loss of admission. So make sure you are well-organized.

Submission Guidelines

In order to be accepted for the review process, your essay must strictly conform with the following regulations. Violations will result in exclusion from the workshop and thus, exclusion from the NetSec exam. So please read the following carefully and make sure your essay will comply with these submission guidelines.

• The number of authors is limited to at most three authors per essay. Organization of group members and group-internal division of work is at your own responsibility.
• The essays will be reviewed in double-blind mode. They must be submitted in a form suitable for anonymous review: no author names may appear on the title page, and papers should avoid revealing their identity in the text. Contact the program chair This email address is being protected from spambots. You need JavaScript enabled to view it. if you have any questions. Papers that are not properly anonymized may be rejected without review. Please note that only the essay itself, not the registration at easychair (see below) must be anonymized. Since students from other groups may be your reviewer in the review process, it is strongly recommended not to reveal your topic other groups or students outside the lecture to obtain unbiased reviews.
• The length of the essay must be at least 2 pages per author and at least 3 pages in total. So if you plan to write your essay alone, you will have to write more.
• Essays must be written using the LaTeX markup language. Knowing LaTeX is a key skill in the academic world. If you are not familiar with LaTeX yet, there is plenty of documentation and examples available online. As common for international research conferences, essays must be formatted for US letter (not A4) size paper. The text must be formatted in a two-column layout, with columns no more than 9.5 in. tall and 3.5 in. wide. The text must be in Times font, 10-point, with 11-point or 12-point line spacing. Authors are strongly encouraged to use the IEEE conference proceedings templates. Its default settings when using \documentclass[10pt, conference, letterpaper]{IEEEtran} are accepted.
• Submissions must be in Portable Document Format (.pdf). Authors should pay special attention to unusual fonts, images, and figures that might create problems for reviewers. Your document should render correctly in Adobe Reader 9 and when printed in black and white.
• We expect every student to use at least 2 references. Use the bibliography of the NetSec slides (last set of slides) or search engines like Google Scholar to find literature on your topic. That means, if you are writing your essay in a group of three students, your essay should list at least 6 references. Use e.g. BibTeX for referencing.
• Plagiarism in any form is unacceptable and is considered a serious breach of professional conduct. If you refer to information from other sources directly or indirectly, indicate the original source carefully using references. We will use plagiarism detection tools, so make sure you do not copy without referencing the source. For referencing and bibliography examples, please check e.g. the papers referenced in the NetSec lecture. It is again strongly recommended to use the IEEE bibliography style as shown here. This style is common for computer science papers.
• Essays must be submitted at https://easychair.org/conferences/?conf=phylisec16 and may be updated at any time until the submission deadline (see above). On registration, EasyChair requires you to enter your address. If you feel uncomfortable with providing your data to EasyChair (although it is a reputable platform), please do not hesitate entering e.g. the address of the TU Kaiserslautern instead of your private one.
• Fairness: In case one of your group mates does not deliver her/his part of the essay, do not hesitate to omit the name when registering the essay on the submission platform. To keep this exercise fair, you do not have to do the work for lazy group mates.  Work should be evenly distributed to all group members. For instance, if only two of the three group members are actually doing the work, enter only these two names on EasyChair. Also the required number of pages is then reduced accordingly to 4 (or 3 if only one is doing all the work).

Review Guidelines

After you've submitted your essay, it's time to start the review phase of the PhyLiSec workshop. Therefore, you have been added to the so called "Program Committee" on Easychair and Carolina has assigned two essays to all of you. If you have no account on EasyChair yet, use the email address your group mate entered in your submission. The reviews will be double-blind. That means, neither you know who you are reviewing, nor the other authors will know who reviewed them.

For each of your two assigned essays, you have to write a short review. Start with reading the essays carefully and then fill in this text template for each essay. Each section in the review (summary/strengths/weaknesses/feedback) should have at least 100 words. Be concise and provide arguments for your statements. The reviews will serve as a basis for improvements in the revision phase and all reviewers should keep this in mind. Finally, rate the essay between very bad (-2) and very good (2).

Plagiarism: In case you learn that the essay you are reviewing is a case of plagiarism, we recommend to reject the paper by rating it with -2. In such a case, please provide proof for your allegation by referencing the respective parts of the essay. Examples for plagiarism (which have already been found) would be if the essay is almost completely copied from other works.

The deadline for the review submission is at 23:59 on the 29th of January. You can find the essays assigned to you under "Reviews->My papers" on Easychair. To submit a review, click on the green "+"-Button and enter your review into the form.

Final Version

As mentioned in the notification email, those of you who are not rejected need to revise their essay according to the comments in the reviews until the 9th of February at 23:59. You can upload your revised essay on EasyChair. To do so, please change your role back to author (PhyLiSec16->Change Role).

Proceedings

The final versions of the papers are listed below. They are supposed to serve as an additional source for information for the exam preparation. Thanks everyone for participating and producing these valuable resources. The five best essays (according to the reviews) are marked with ★. Congratulations!

Organization

Course Overview

The objective of this lecture is to introduce the art of perfomance-related modeling of complex distributed systems.

• Performance dimensioning of planned systems
• Performance control of running systems
• Quality of service guarantees in distributed systems
• Resource management in distributed systems

The focus will be on different analytical methods for performance modeling:

• Tail-bounded Network Calculus
• MGF-bounded Network Calculus
• Application examples / case studies

Slides and Script

The slides are accessible only from within the university network (131.246.*). Please use SSH or VPN for remote access.

There is a script, which includes the topics of the course, written by Michael Beck. The chapters of the script will be published, as the course advances:

Examination

Dates for the oral examinations will be announced.

To qualify for the examination students are required to partake in the exercises.

Exercises

The exercises to this course will be based on a wiki. Further information can be found on the lecture slides.

To participate in the exercises students need to register here:

https://131.246.19.102/registration/stocads1516/

The registration opens 27 November 2015 at 11 AM and closes 29 November 2015 at midnight.

Participating in the exercises is mandatory to be eligible for the examination!

The first meetup for the StocADS-Wiki takes place on Friday 20th, 11:45 in 36-438.

Literature

• Jean-Yves Le Boudec, Patrick Thiran. Network Calculus. Springer, 2001. (Also →available online)
• Cheng-Shang Chang, Performance Guarantees in Communication Networks. Springer, 2000.
• Yuming Jiang, Stochastic Network Calculus. Springer, 2008.

Organization

Please find the slides of our kick-off meeting last Friday here. If you decide to participate in the project, you can register via email to This email address is being protected from spambots. You need JavaScript enabled to view it. until next Friday, the 22nd of January. Further instructions will follow via email just before the project's start in February.

Instructors

M.Sc. Daniel Berger
M.Sc. Matthias Schäfer

Follow #PEDSproject and @DISCO_Teaching.

Literature Research

Please find the results of the first phase here:

• Group 1: Alexander and Fahru
• Group 2: Khojema and Subin
• Group 3: Daniel, Markus, and Philipp

Maximum Compression Ratio

Our goal is to find a trade-off between compression ratio and timeliness. Information which is older than 1 second is considered outdated and must be ignored. So the first requirement is to transmit messages at latest 1s after its reception. However, we first start with finding the algorithm(s) which suit(s) our data best.

Therefore, use this trace of binary sensor data and find the algorithm with the maximum compression ratio. The data is formatted as follows:

<esc> "2" : 6 byte MLAT timestamp, 1 byte signal level, 7 byte Mode-S short frame
<esc> "3" : 6 byte MLAT timestamp, 1 byte signal level, 14 byte Mode-S long frame

where

<esc><esc>: true 0x1a (i.e. 0x1a's within packets are escaped)
<esc> is 0x1a, and "1", "2" and "3" are 0x31, 0x32 and 0x33

The original format description can be found here. The upper 18 bit of the MLAT timestamp are the seconds of the day, the lower 30 bits are the nanoseconds of the second of the day. The Mode-S frames are encoded according to ICAO Annex 10 Volume IV. Find the Mode S message encoding in this file.

Results

The maximum compression ratio of about 2.2 has been achieved with LZMA. An additional 10% improvement can be achieved with some optimizations: reducing the entropy by XORing the CRC and removing ESC chars. However, the high compression ratio is paid for with a high computation time of up to 4 minutes. Find the presentation with the details below:

• Group 1: Alexander and Fahru
• Group 2: Khojema and Subin
• Group 3: Daniel, Markus, and Philipp

Stripped Data

Group 3 provided a clean dataset without the escape characters (so each message directly starts with 2 -> short message (15 Bytes) or 3 -> long message (22 Bytes)), they removed unnecessary messages, and they XORed the CRC so that the entropy is lower. They also provided the chunks needed for the next task. Find both, the complete clean and optimized dataset as well as the chunks here.

Chunk Size vs. Compression Ratio & Profiling

In the third task, we investigated the effect of the datasize on the compression ratio and compression time. Since we aim at compressing very small chunks of data, the investiated chunk sizes are 1, 2, 4, ..., 1024 Radarcape messages. Three compression algorithms were tested: LZMA, deflate (gzip, zlib), and burrows wheeler. Interestingly, while in the previous task LZMA was the outstanding winner with the best compression ratio for the complete dataset, the results of this experiment show that for these very small datasets, all algorithms and compression levels perform more or less equally good.

In addition to the compression ratio for different chunksizes, we profiled the execution time of the different steps of compression algorithms. The results clearly show, that matching the longest symbols is the most expensive task for dictionary-based compression schemes.

Find the presentation with the details below:

• Group 1: Alexander and Fahru
• Group 2: Khojema and Subin
• Group 3: Daniel, Markus, and Philipp

Stream-Compression Implementation

Two-week task: March 7 until March 18.

PEDS Project Report

Use Latex and this template (DiscoReport.zip).

1. Intro and Problem Statement (2 pages)
2. Literature Research + Table of Compression Algorithms (2 pages)
3. Performance Evaluation of Classical Algorithms
   1. Max Compression Ratio + plot (1 page)
   2. Compression Ratio with Message Chunks + plot (1 page)
   3. Profiling of Execution Time + plot (1 pages)
4. Stream Compression System Design (2 pages)
5. Performance Evaluation of Stream Compression System + plots (3 pages)
6. Conclusions and Future Work (1 page)

Organization

Course Overview

This course covers aspects and principles of network security. Based on many attacks on common technologies used in communication systems, this course illustrates how things can go wrong and provides basic measures to protect a network from mistakes commited in the past. It covers furthermore the fundamental concepts of security and security problems.

Areas covered in this lecture:

• Physical and Link Layer Security
• Network Layer Security
• Transport Layer Security
• Application Layer Security

Please note that it is strongly recommended to attend communication systems first since it provides the background knowledge for this lecture.

Exercises

The workshop (first exercise) website can be found here. The proceedings (results) of the workshop are also online.

The first hack challenge (second exercise) can be found here.

The second hack challenge (third exercise) can be found here.

Examination

The final results of the exam can be found here. Well done :-)

The written exam will be held on Monday, March 21st 2016 at 8:30am in room 42-115. It will last about 60 minutes. Please be there at latest by 8:15am, we will start on time. Again: Please check the list of admissions below!! There are some registrations without admission. They will be cancelled automatically if you don't do anything. You will not be allowed to participate in the exam without admission! In addition, to avoid any trouble on Monday check the QIS if you are properly registered for the exam. Please contact the Prüfungsamt and This email address is being protected from spambots. You need JavaScript enabled to view it. BEFORE the exam if there is any trouble with your registration.

Exam Admission

Find the list of the students who passed the exercises and got the admission here. If you registered for the exam but you are not on the list, please cancel your registration. In case you don't, the Prüfungsamt will cancel it for you. If you are not on the list but you think you should be, please contact This email address is being protected from spambots. You need JavaScript enabled to view it..

Slides

The slides are accessible only from within the university network (131.246.*). Please use SSH or VPN for remote access.