Summer 2017

The art of cryptography: secure internet & e-passports


This course is about various aspects of security in the internet. In the first part we deal with secure connections, whereas the second part considers electronic voting schemes involving further tasks.

  • Who can read my email?
  • How do I know that eBay is eBay, or amazon is amazon?
  • What is the public key of Angela Merkel? Where do I get it and how do I verify that it's really hers?
  • ...

In the internet a large variety of protocols ("chatting programs") are in use to make this or that `secure'. VPN, IPsec, SSL, PKI, PGP are just a few tokens that need explanations. We will try to understand a little of that and how things are used and made available. We aim at also considering their security relative to the used primitives.

Passports shall carry more and more sensitive information in a easily accessible way in the future. This information may, apart from name, origin and the like, contain fingerprints or retina scans. And it is stored in electronic form, and it can be accessed by wireless transmissions. This raises a lot of new problems:

  • The passport holder cannot immediately control the contents of the stored information.
  • Unauthorized eavesdroppers might be able to gather or actively read information from the passport unnoticed. So one could think that identifying a certain person passing at a certain place, or tracking her path through a department store might be possible.
  • Personal rights of a person are touched when acquiring and storing biometric information.

The course will try to give an overview what and how things are implemented. We will discuss the concerns of and threats to holders, society and government. Biometrical information has long been used to identify persons. Already, in 1901 Scotland Yard started to use fingerprints to identify criminals. Since then various other methods have been introduced: iris scan, face recognition, retina scans, hand geometry to name just the most prominent. Since about 1965 people have tried to automate all these identification methods. This has shown many difficulties. It is still not clear which information identify a person: for example, though it is widely believed that fingerprints do, only few scientific studies are available. And it turns out to be pretty difficult to find a reliable automatic pattern matcher. Mind that it is not like searching a given fixed string in a dictionary. You have to find the template(s) that are most similar to a given one, or tell that there is none within given bounds.


Michael Nüsken

Time & Place

  • Monday, 1230-1400, b-it bitmax.
  • Thursday, 1230-1400, b-it bitmax.
  • Tutorial: Monday, 1415-1545, b-it bitmax.

First meeting: Thursday, 20 April 2017, 1230.

Notes & Exercises

You find notes and exercises at sciebo until March 2018.


Basic knowledge in cryptography is needed, as for example the course Cryptography held in the previous winter. Compare our programme.


4+2 SWS.

  • Master in Media Informatics: Computer and Communication Technology.
    8 ECTS credits.
    Optionally, 3+2 SWS, 6 ECTS credits. On request a breakpoint at about 3/4 of the teaching time will be defined, and only the course material up to that point will be relevant for their exams and grades.
  • Master in Computer Science at University of Bonn: MA-INF 1312.
    9 CP.
    Students have to register this course with POS/BASIS.
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