Dr. Christian Deppe
Technical University of Munich
Chair of Communications Engineering (Prof. Kramer)
Postal address
Postal:
Theresienstr. 90
80333 München
 Phone: +49 (89) 289  23458
 Room: 0104.03.404
 christian.deppe@tum.de
Biography
Christian Deppe received the Dipl.Math. degree in mathematics from the Universität Bielefeld, Bielefeld, Germany, in 1996, and the Dr.Math. degree in mathematics from the Universität Bielefeld, Bielefeld, Germany, in 1998. He was a Research and Teaching Assistant with the Fakultät für Mathematik, Universität Bielefeld, from 1998 to 2010. From 2011 to 2013 he was project leader of the project ``Sicherheit und Robustheit des QuantenRepeaters´´ of the Federal Ministry of Education and Research at Fakultät für Mathematik, Universität Bielefeld. In 2014 he was supported by a DFG project at the Institute of Theoretical Information Technology, Technische Universität München. In 2015 he had a temporary professorship at the Fakultät für Mathematik und Informatik, FriedrichSchiller Universität Jena. He is currently project leader of the project ``Abhörsichere Kommunikation über QuantenRepeater´´ of the Federal Ministry of Education and Research at Fakultät für Mathematik, Universität Bielefeld. Since 2018 he is at the Department of Communications Engineering at the Technical University of Munich.
Teaching
 SS 2014 Lecture: Data transmission with feedback
 WS 2014/2015 Lecture: Quantum Information Theory
 SS 2015 Lecture: Computability and Complexity
 SS 2015 Lecture: Information Theory
 SS 2015 Lecture: Numerical Mathematics  Supplements
 WS 2015/2016 Lecture: Quantum Information Theory
 SS 2016 Lecture: Quantum Information Theory
 WS 2016/2017 Lecture: Quantum Information Theory
 SS 2018 Lecture: Multi User Information Theory
 WS 2018/2019 Lecture: Nachrichtentechnik II
 SS 2019 Lecture: Multi User Information Theory
 SS 2019 Lecture: Nachrichtensysteme  Kommunikationssysteme (LB)
 WS 2019/2020 Lecture: Nachrichtentechnik II
Research
Secrecy Capacity of Classical  Quantum Channels
Investigation into communication via quantum channels started in the 1960s. Quantum mechanics differs significantly from classical mechanics, it has its own laws. Quantum information theory unifies information theory with quantum mechanic, generalizing classical information theory to the quantum world.
A quantum channel can transmit both classical and quantuminformation. We consider the capacity of quantum channels carrying classical information. This is equivalent toconsidering the capacity of classicalquantum channels, where the classicalquantum channels are quantum channels whose sender’s inputs are classical variables. We determine the secrecy capacity of the several channel with (quantum) wiretapper.
Message Transmission under Jamming Attacks
Our goal is to investigate in communication that takes place over a channel which is, in addition to the noise, subjected to the action of a jammer which actively manipulates the channel. A channel with a jammer is called an arbitrarily varying channel, where the jammer may change his input in every channel use and is not restricted to use a repetitive probabilistic strategy. In the model of an arbitrarily varying channel, we consider a channel which is not stationary and can change with every use. We interpret this as an attack of a jammer. It works as follows: the sender and the receiver have to select their coding scheme first. After that the jammer makes his choice to sabotage the message transmission. However, due to the physical properties, we assume that the jammer’s changes only take place in a known set. We consider classical and classicalquantum channels with a jammer and determine the (secrecy) capacity.
Identification over Channels
The implementation of this communication in today’s systems mostly based on the communication theory of Shannon. In this communication model, it is always assumed that the receiver’s goal is to decode all messages. Due to this strong goal, the coding scheme is inefficient for some cases. Ahlswede and Dueck have shown that there are more efficient solutions when the recipient’s goal changes. Instead of the decoder wanting to decode the message, he is only interested in whether a specific message has been sent. However, the sender does not know which message is interesting for the receiver. This communication task is called identification. We consider classical and classicalquantum channels with a jammer and determine the (secrecy) identification capacity.
ErrorCorrecting Codes with Feedback
We consider the problem of transmitting messages over a noisy channel with noiseless feedback. A sender wants to transmit a message over a noisy binary channel. We have a passive feedback, that means that the sender always knows what has been received. The ith code letter depends on the message we want to transmit and the (i1) symbols which have been received before. We suppose that the noise does not change more than a fixed number of symbols of a codeword. We consider several channel models with partial feedback and limited magnitude and construct coding strategies. Furthermore, we determine the capacity error function for these channels.
Books
[Translate to en:]  Ahlswede, Rudolf; Bäumer, Lars; Cai, Ning; Aydinian, Harout; Blinovsky, Vladimir; Deppe, Christian; Mashurian, Haik (Eds.) General Theory of Information Transfer and Combinatorics SpringerVerlag Series: Lecture Notes in Computer Science, Vol. 4123 1st Edition, 2006, ISBN: 9783540462453 Also availabel ONLINE 
Aydinian, Harout; Cicalese, Ferdinando; Deppe, Christian (Eds.) Information Theory, Combinatorics, and Search Theory In Memory of Rudolf Ahlswede SpringerVerlag Series: Lecture Notes in Computer Science, Vol. 7777 1st Edition, 2013, ISBN: 9783642368981 Also availabel ONLINE 

Ahlswede, Alexander; Althöfer, Ingo; Deppe, Christian; Tamm, Ulrich (Eds.) Storing and Transmitting Data Rudolf Ahlswede's Lectures on Information Theory 1 SpringerVerlag Series: Foundations in Signal Processing, Communications and Networking, Vol. 10 1st Edition, 2014, ISBN: 9783319054780 Also availabel ONLINE 

Ahlswede, Alexander; Althöfer, Ingo; Deppe, Christian; Tamm, Ulrich (Eds.) Transmitting and Gaining Data Rudolf Ahlswede's Lectures on Information Theory 2 SpringerVerlag Series: Foundations in Signal Processing, Communications and Networking, Vol. 11 1st Edition, 2015, ISBN: 9783319125220 Also availabel ONLINE 

Ahlswede, Alexander; Althöfer, Ingo; Deppe, Christian; Tamm, Ulrich (Eds.) Hiding Data  Selected Topics Rudolf Ahlswede's Lectures on Information Theory 3 SpringerVerlag Series: Foundations in Signal Processing, Communications and Networking, Vol. 12 1st Edition, 2016, ISBN: 9783319315133 Also availabel ONLINE 

Ahlswede, Alexander; Althöfer, Ingo; Deppe, Christian; Tamm, Ulrich (Eds.) Combinatorial Methods and Models Rudolf Ahlswede's Lectures on Information Theory 4 SpringerVerlag Series: Foundations in Signal Processing, Communications and Networking, Vol. 13 1st Edition, 2017, ISBN: 9783319531397 Also availabel ONLINE 

Ahlswede, Alexander; Althöfer, Ingo; Deppe, Christian; Tamm, Ulrich (Eds.) Probabilistic Methods and Distributed Information Rudolf Ahlswede's Lectures on Information Theory 5 SpringerVerlag Series: Foundations in Signal Processing, Communications and Networking, Vol. 13 1st Edition, 2019, ISBN: 9783030003128 Also availabel ONLINE 