Secure and Dependable Systems


  • Course: Secure and Dependable Systems (CO21-320203)
  • Semester: Spring 2018
  • Instructor: Jürgen Schönwälder
  • TA: Liu, Yufei
  • TA: Xhelili, Orgest
  • Class: Monday, 08:15-09:30, Lecture Hall Research I
  • Class: Friday, 09:45-11:00, Conference Room Research IV


This course introduces formal methods for analyzing and assuring safety and security of software systems. The course starts off with a clarification of concepts such as dependability, quality, safety, and security of software systems, and how to achieve them in the software development process. We introduce the foundations of cryptography as a basis for security mechanisms. The main part of the course introduces different paradigms of safety/security analysis such as formal testing (code coverage), static program analysis (control/data flow analysis and abstract interpretation), model checking (computational tree logic), and program verification (Hoare calculus, dynamic logic). The formal techniques will be used for analyzing both safety and security properties of programs. Where possible, students will be given hands-on micro-projects in state-of-the-art tools (e.g., Isabelle for program verification).


  • Bruce Schneier: Applied Cryptography, 20th Anniversary Edition, Wiley, 2015
  • Wm.A. Conklin, Gregory White: Principles of Computer Security, 5th Edition, McGraw-Hill, 2018
  • Simon Singh: The Code Book: Science of Secrecy from Ancient Egypt to Quantum Cryptography, Anchor Books, 2000


Mo 08:15 Fr 09:45 Topics
2018-02-02 Introduction (Spectre)
2018-02-05 2018-02-09 Dependability Concepts and Classic Computing Disasters
2018-02-12 2018-02-16 Software Engineering and Testing
2018-02-19 2018-02-23 Software Specification and Verification
2018-02-26 2018-03-02 Automated Generation of Proof Goals and Termination Proofs
2018-03-05 2018-03-09 Time, Events, and Causality in Distributed Systems
2018-03-12 2018-03-16 Broadcast Algorithms, Communicating Sequential Processes
2018-03-19 2018-03-23 Communicating Sequential Processes
2018-03-26 2018-03-30 [Spring Break]
2017-04-02 2018-04-06 Midterm Exam (Campus Center Eastwing)
2018-04-09 2018-04-13 Basic Concepts of Cryptography and Symmetric Encryption Algorithms and Block Ciphers
2018-04-16 2018-04-20 Asymmetric Encryption Algorithms, Cryptographic Hash Functions, Certificates
2018-04-23 2018-04-27 Key Management Schemes, Pretty Good Privacy
2018-04-30 2018-05-04 Transport Layer Security and Secure Shell
2018-05-07 2018-05-11 Steganography, Covert Channels, Anonymity, Trusted Computing
2018-05-14 Review and Exam Preparation


Date/Due Name Topics
2018-02-26 Sheet #1 unit testing and coverage (stack and rpn calculator)
2018-03-08 Sheet #2 partial correctness and total correctess of the gcd algorithm
2018-04-04 Sheet #3 logical clocks and communicating sequential processes
2018-04-06 Midterm Exam 09:45-11:00 East Wing (closed book, hand written cheat sheet (one single-sided a4 page or a double-sided a5 page) allowed)
2018-04-24 Sheet #4 symmetric encryption and proof of work
2018-05-16 Sheet #5 gpg keys, X.509 certificates, ocsp
2018-05-25 Final Exam 09:00-11:00 Conference Hall (closed book, hand written cheat sheet (one single-sided a4 page or a double-sided a5 page) allowed)


The final grade is made up of the final exam (40%), a midterm exam (30%) and homework assignments (30%).

Electronic submission is the preferred way to hand in homework solutions. Please submit documents (plain ASCII text or PDF, no Word) and your source code (tar, zip) via the online submission system. If you have problems, please contact one of the TAs.

Late submissions will not be accepted. Homeworks may need to be defended in an oral interview.

For any questions stated on assignment sheets, quiz sheets, exam sheets or during makeups, we by default expect a reasoning for the answer given, unless explicitely stated otherwise.

Students must submit solutions individually. If you copy material verbatim from the Internet (or other sources), you have to provide a proper reference. If we find your solution text on the Internet without a proper reference, you risk to lose your points. Any cheating cases will be reported to the registrar. In addition, you will lose the points (of course).

Any programs, which have to be written, will be evaluated based on the following criteria:

  • correctness including proper handling of error conditions
  • proper use of programming language constructs
  • clarity of the program organization and design
  • readability of the source code and any output produced

Source code must be accompanied by a README file providing an overview of the source files and giving instructions how to build the programs. A suitable Makefile is required if the build process involves more than a single source file.

If you are unhappy with the grading, please report immediately (within one week) to the TAs. If you can't resolve things, contact the instructor. Problem reports which come late, that is after the one week period, are not considered anymore.

The policy on makeup quizzes is the following: There won't be any quiz makeups. If you (a) get an official excuse for a quiz from the registrar's office or (b) approach we well in advance of the quiz with a very good reason for not being able to participate (e.g., because you take a GRE computer science subject test at the day of a quiz), then the weight of the final exam will be increased according to the weight of the quiz you got excused for.