Angebotene Arbeiten

Bei Interesse an einer Bachelor oder Master Arbeit, einer Ingenieurs- oder Forschungspraxis oder einer Werkstudententätigkeit, können Sie sich auch direkt an unsere Doktoranden wenden. Es sind oftmals Themen in Vorbereitung, die hier noch nicht aufgelistet sind und es besteht die Möglichkeit ein Thema entsprechend Ihrer Interessenlage zu finden.
Bitte legen Sie jeder Bewerbung einen Lebenslauf sowie eine Liste der besuchten Lehrveranstaltungen bei.
Wenn Ihre Ingenieurspraxis vom Studiendekanat an einen unserer Professoren zugeteilt wurde, wenden Sie sich damit bitte an Frau Dorn (Raum N2401).

Bachelorarbeiten

[identification] Idnetification and Secrecy with Physically-Unclonable-Functions (PUFs)

Stichworte:
PUF secrecy identification

Beschreibung

Identification is a communication scheme that allows rate doubly exponential in the blocklemght, with the tradeoff that identities cannot be decoded (as messages do) but can only be verified.

Identification codes can be achieved by first removing the errors from the channel with regular transmission channel coding, and then sending a challenge though the corrected channel. For every identity i, The channenge is generated by picking a random input m and computing the corresponding output T_i(m) using a function T_i that depends on the identity. The challenge is then the pair m,T_i(m) and the receiver wanting to verify an identity j will verify whether j=i by testing the challenge. This is done by recomputing the output with T_j and verifying whether T_j(m)= T_i(m). The errors are reduced by ensuring that the various functions collide on a small fraction of the possible inputs.

It turns out that choosing good sets of funtions {T_i} is the same as choosing error-correction codes {c_i} with large distance, where now each codeword c_i defines a function by mapping positions m (sometimes called code locators) to symbols c_im of the codeword.
We can thus construct identification codes by choosing error-correction codes where we are only interested in the performance of the error correction encoders (we are not interested in the error-correction decoder or error-correction codes).

From previous work we have a fairly efficient implementation based Reed-Muller code which can be found at

Secrecy in this identification codes has also been implemented in unpublished work. Furthermore, the theoretical work on Identification with PUF's has been done in

The goal of the project will be to bridge the three topics and create practical and efficient secret identification codes in the PUF setting.

The working language will be in English.

Environment: this is a project in collaboration with LTI. At LNT and LTI there is currently a lot of funding for research in identification. Therefore you will find a large group of people that might be available for discussion and collaboration.

Betreuer:

[identification] Implementation of identification with universal hash functions

Stichworte:
universal hash identification

Beschreibung

Identification is a communication scheme that allows rate doubly exponential in the blocklemght, with the tradeoff that identities cannot be decoded (as messages do) but can only be verified.

The double exponential growth presents various challenges in the finite regime: there are heavy computational costs introduced at the encoder and decoder and heavy trade-offs between the error and the codes sizes.

The ultimate goal is to find a fast, reliable implementation while still achieving large code sizes.

Identification codes can be achieved by first removing the errors from the channel with regular transmission channel coding, and then sending a challenge though the corrected channel. For every identity i, The channenge is generated by picking a random input m and computing the corresponding output T_i(m) using a function T_i that depends on the identity. The challenge is then the pair m,T_i(m) and the receiver wanting to verify an identity j will verify whether j=i by testing the challenge. This is done by recomputing the output with T_j and verifying whether T_j(m)= T_i(m). The errors are reduced by ensuring that the various functions collide on a small fraction of the possible inputs.

It turns out that choosing good sets of funtions {T_i} is the same as choosing error-correction codes {c_i} with large distance, where now each codeword c_i defines a function by mapping positions m (sometimes called code locators) to symbols c_im of the codeword.
We can thus construct identification codes by choosing error-correction codes where we are only interested in the performance of the error correction encoders (we are not interested in the error-correction decoder or error-correction codes).

Your task will be implementing the identification codes described in

aiming at the fastest implementation, and testing their performance in comparison to other current implementations.

For reference, our previous work on identification based on Reed-Solomon and Reed-Muller code can be found at

The coding will be in Python/Sagemath.
The working language will be in English.

Environment: we collaborate with LTI. At LNT and LTI there is currently a lot of funding for research in identification. Therefore you will find a large group of people that might be available for discussion and collaboration.

Betreuer:

Masterarbeiten

Automatic Bias Control for Optical IQ Modulation in Quantum Communications

Beschreibung

For our Advanced Technology team in Munich/Martinsried, we are looking for a motivated master thesis student at the intersection of optical (quantum) communications, electrical engineering, and cyber security. With the advancement of the continuous variable QKD (CV-QKD), information can be encoded on the quadratures of the incident electromagnetic field, like in commercial optical communication systems. This allows the information on coherent states of light to be captured at the receiver. Similar to coherent optical communications, Inphase & Quadrature (IQ) modulation is a crucial step for the generation of the QKD transmit signal . For this step the modulator, usually a Mach-Zehnder modulator (MZM), imprints the electrical baseband DAC output onto the continuous wave laser light.

Throughout this thesis work, the student’s main task will be to research, analyze and implement a practical IQ modulator for QKD applications.

Kontakt

utku.akin@advasecurity.com

Betreuer:

Utku Akin - Utku Akin (Adva Network Security GmbH)

Nonlinear Effects in Multi-Core Fibers

Stichworte:
nonlinearity, optical communications, mcf, multicore fibers

Beschreibung

Space-division multiplexing (SDM), which consists in exploiting multimode fibers (MMFs) or multicore fibers (MCFs) instead of single mode ones, is one of the future optical communications architectures to increase data rates and network planning flexibility. The nonlinear properties of MCFs are of primary interest in assessing the usefulness of SDM against the current network. With this thesis, the student has the chance to work on a state-of-the-art topic in the field of optical communication systems, and progress quickly thanks to a tight (if desired) supervision. Would you be curious to know more about it? If so, just get in touch with me at paolo.carniello@tum.de (personal page https://www.ce.cit.tum.de/lnt/mitarbeiter/doktoranden/carniello/).

Voraussetzungen

-some knowledge on optical communications systems (e.g., Optical Communication Systems or Simulation of Optical Communication Systems Lab)

-some knowledge about communications engineering topics

Kontakt

paolo.carniello@tum.de
See https://www.ce.cit.tum.de/lnt/mitarbeiter/doktoranden/carniello/ for more info on the supervisor.

Betreuer:

Error Resilience in the Number-Theoretic Transform – PQC acceleration for safetycritical applications

Stichworte:
post-quantum cryptography, HW acceleration, number theoretic transform

Beschreibung

Asymmetric cryptography is a core component of modern communication infrastructure. The existence of a sufficiently large quantum computer threatens all algorithms currently in use and recent developments in this field motivate the field of post-quantum cryptography (PQC), with the primary objective of developing secure and futureproof alternatives. To consolidate these efforts, the National Institute of Standards and Technology (NIST) is conducting a competition with the goal of selecting and standardizing the best available candidates.

In July 2022 four algorithms were selected, one Public-key Encryption and Key-establishment Algorithms (KEM) and three Digital Signature Algorithms (DSA). Of these four algorithms, three (including the two recommended for general purpose applications) are from the class of lattice-based schemes, i.e., they rely on difficult problems over lattices for their security.

The lattices in these schemes are represented by elements from a polynomial ring and arithmetic over this ring therefore plays a crucial role in their execution. To accelerate this arithmetic and, specifically, the multiplication of polynomials, the number-theoretic transform (NTT) is used. This approach is a generalization of the multiplication algorithms based on the fast Fourier transform (FFT), that have been long established in fields like signal processing. Since a considerable part of the computational complexity of these algorithms lies in this NTT, it is a prime candidate for HW acceleration and many works in literature have proposed such accelerators.

While considerable efforts have been made to offer fast and lean NTT accelerators, the topic of fault resilience has received little attention so far. In safety critical applications, as common in automotive or industrial fields, this resilience is an important feature and needs to be provided by the HW. On the other hand, these fields are traditionally price sensitive, so the additional chip area required for these features should be minimal. However, current approaches, such as those introduced by Sarker et al. [1], impose a large area (or latency) overhead.

The goal of this thesis is to address this shortcoming. First, the approaches published in literature shall be evaluated with regard to the relevant performance figures (area overhead, latency, …). Then, new approaches for error resilience in NTT calculation shall be developed, either based on improving upon existing methods or by adapting methods for error resilience in the computation of FFTs.

References

[1] Sarker, Ausmita, Alvaro Cintas Canto, Mehran Mozaffari Kermani, and Reza Azarderakhsh. “Error Detection Architectures for Hardware/Software Co-Design Approaches of Number-Theoretic Transform.” IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems, 2022, 1–1. https://doi.org/10.1109/TCAD.2022.3218614.

Voraussetzungen

Basic understanding of HW design

Good knowledge of algebra

Kontakt

georg.maringer@tum.de

 

Betreuer:

Georg Maringer - Lukas Holzbaur, Alexander Zeh (Infineon Technologies)

Efficient Block Propagation in Cryptocurrency Networks

Beschreibung

Cryptocurrencies like Bitcoin and Ethereum use a decentralized ledger called Blockchain to track transactions. Whenever a new block is added to the Blockchain, the change is spread through the network using a gossip-like protocol. This process is known as block propagation.

To increase scalability, the efficiency of block propagation is crucial. This thesis aims to explore the information theoretic limits of block propagation, derive realistic models based on real data, and investigate innovative and efficient techniques for block propagation.

The thesis will be conducted at the Institute of Communications and Navigation at DLR (German Aerospace Center) in Oberpfaffenhofen.

Voraussetzungen

Required qualifications are

  • basic knowledge of information theory
  • programming experience in Matlab, C, or python.
  • Interest in cryptocurrencies.

Kontakt

Interested applicants may contact Dr. Francisco Lázaro via email at francisco.lazaroblasco@dlr.de.

Betreuer:

Juan Diego Lentner Ibanez - Dr. Francisco Lázaro (DLR (German Aerospace Center))

[identification] Idnetification and Secrecy with Physically-Unclonable-Functions (PUFs)

Stichworte:
PUF secrecy identification

Beschreibung

Identification is a communication scheme that allows rate doubly exponential in the blocklemght, with the tradeoff that identities cannot be decoded (as messages do) but can only be verified.

Identification codes can be achieved by first removing the errors from the channel with regular transmission channel coding, and then sending a challenge though the corrected channel. For every identity i, The channenge is generated by picking a random input m and computing the corresponding output T_i(m) using a function T_i that depends on the identity. The challenge is then the pair m,T_i(m) and the receiver wanting to verify an identity j will verify whether j=i by testing the challenge. This is done by recomputing the output with T_j and verifying whether T_j(m)= T_i(m). The errors are reduced by ensuring that the various functions collide on a small fraction of the possible inputs.

It turns out that choosing good sets of funtions {T_i} is the same as choosing error-correction codes {c_i} with large distance, where now each codeword c_i defines a function by mapping positions m (sometimes called code locators) to symbols c_im of the codeword.
We can thus construct identification codes by choosing error-correction codes where we are only interested in the performance of the error correction encoders (we are not interested in the error-correction decoder or error-correction codes).

From previous work we have a fairly efficient implementation based Reed-Muller code which can be found at

Secrecy in this identification codes has also been implemented in unpublished work. Furthermore, the theoretical work on Identification with PUF's has been done in

The goal of the project will be to bridge the three topics and create practical and efficient secret identification codes in the PUF setting.

The working language will be in English.

Environment: this is a project in collaboration with LTI. At LNT and LTI there is currently a lot of funding for research in identification. Therefore you will find a large group of people that might be available for discussion and collaboration.

Betreuer:

[quantum] Quantum Machine Learning for Communication

Stichworte:
physical, layer, quantum, machine learning, non-linear

Beschreibung

As part of an ongoing project with Huawei we are looking into quantum machine learning algorithms applied to decoding at the end of an optical fiber in the non-linear regime.

So far we have tried only the quantum version of k-mean clustering, however the goal is to test further quantum algorithms, in particular quantum support vector machines next, and their classical quantum-inspired counterpart.

The projects will involve reading the literature on quantum machine learning algorithms and quantum-inspired algorithms, find or come up with an implementation (this will involve the use of quantum libraries, in particular so far we have use qiskit), and benchmark the performance.

Voraussetzungen

Knowledge of quantum mechanics or quantum information is highly recommended.

Betreuer:

[identification] Implementation of identification with universal hash functions

Stichworte:
universal hash identification

Beschreibung

Identification is a communication scheme that allows rate doubly exponential in the blocklemght, with the tradeoff that identities cannot be decoded (as messages do) but can only be verified.

The double exponential growth presents various challenges in the finite regime: there are heavy computational costs introduced at the encoder and decoder and heavy trade-offs between the error and the codes sizes.

The ultimate goal is to find a fast, reliable implementation while still achieving large code sizes.

Identification codes can be achieved by first removing the errors from the channel with regular transmission channel coding, and then sending a challenge though the corrected channel. For every identity i, The channenge is generated by picking a random input m and computing the corresponding output T_i(m) using a function T_i that depends on the identity. The challenge is then the pair m,T_i(m) and the receiver wanting to verify an identity j will verify whether j=i by testing the challenge. This is done by recomputing the output with T_j and verifying whether T_j(m)= T_i(m). The errors are reduced by ensuring that the various functions collide on a small fraction of the possible inputs.

It turns out that choosing good sets of funtions {T_i} is the same as choosing error-correction codes {c_i} with large distance, where now each codeword c_i defines a function by mapping positions m (sometimes called code locators) to symbols c_im of the codeword.
We can thus construct identification codes by choosing error-correction codes where we are only interested in the performance of the error correction encoders (we are not interested in the error-correction decoder or error-correction codes).

Your task will be implementing the identification codes described in

aiming at the fastest implementation, and testing their performance in comparison to other current implementations.

For reference, our previous work on identification based on Reed-Solomon and Reed-Muller code can be found at

The coding will be in Python/Sagemath.
The working language will be in English.

Environment: we collaborate with LTI. At LNT and LTI there is currently a lot of funding for research in identification. Therefore you will find a large group of people that might be available for discussion and collaboration.

Betreuer:

[identification] Applications of Identification Codes in V2X Communications

Stichworte:
sumo, ns3, ns-3, vehicular, communication, identification, c++, Reed-Muller

Beschreibung

As part of the NewCom Project, new communication paradigms are investigated from an experimental perspective in order to construct proof-of-concept implementations that demonstrate the theoretical results obtained for Post-Shannon Communication schemes. In particular, this MSc thesis focuses on Identification Codes and their integration into a simulation environment where vehicular networks are modelled.

For this, the master student will first conduct a review of the state-of-the-art use cases for identification in the scientific literature and in form of patents, with an emphasis on V2X communications. By using an open-source V2X implementation based on LDR’s Simulation of Urban Mobility (SUMO) framework integrated with ns-3’s implementation of the ITS-G5 and LTE standards and conducting simulation in specific scenarios, the student will gain a first impression of the performance of the system using traditional transmission schemes. The integration of existing implementation of identification codes culminates this thesis, where KPIs will be defined in order to compare the advantages of using identification instead of transmission in the context of V2X communications.

Details about the C++ tools/libraries

The software used for the simulation of the vehicular network communication is ezCar2x

which build on and integrates the NS-3 (network simulation) and SUMO (traffic simulation) libraries

For the identification part and identification code based on Reed-Muller codes needs to be reimplemented (work in progress) from Python into C++ using the Givaro library

 

 

Voraussetzungen

  • Knowledge of communications engineering, mobile communications, wireless channel models, signal processing, and channel coding techniques (experience in LTE/5G cellular networks is a plus)

  • Interest in novel communication concepts as well in their practical implementation

  • Software experience: MATLAB, C++ and Python (experience with ns-3 or SUMO is a plus)

  • Comfortable working with Linux operative systems and distributed version control tools (e.g., gitlab)

  • Goal-oriented and structured work style

 

Kontakt

To apply, Please send your application by e-mail to Roberto Ferrara (roberto.ferrara@tum.de) and Luis Torres-Figueroa (luis.torres.figueroa@tum.de) with the following documents:

  • Curriculum vitae

  • Academic transcript

  • Short motivation (0.5 – 1 page)

Betreuer:

[identification] Simulation and performance improvement of identification codes

Beschreibung

Identification is a communication scheme that allows rate doubly exponential in the blocklemght, with the tradeoff that identities cannot be decoded (as messages do) but can only be verified.

The double exponential growth presents various challenges in the finite regime: there are heavy computational costs introduced at the encoder and decoder and heavy trade-offs between the error and the codes sizes.

The ultimate goal is to find a fast, reliable implementation while still achieving large code sizes.

Identification codes can be achieved by first removing the errors from the channel with regular transmission channel coding, and then sending a challenge though the corrected channel. For every identity i, The channenge is generated by picking a random input m and computing the corresponding output T_i(m) using a function T_i that depends on the identity. The challenge is then the pair m,T_i(m) and the receiver wanting to verify an identity j will verify whether j=i by testing the challenge. This is done by recomputing the output with T_j and verifying whether T_j(m)= T_i(m). The errors are reduced by ensuring that the various functions collide on a small fraction of the possible inputs.

It turns out that choosing good sets of funtions {T_i} is the same as choosing error-correction codes {c_i} with large distance, where now each codeword c_i defines a function by mapping positions m (sometimes called code locators) to symbols c_im of the codeword.
We can thus construct identification codes by choosing error-correction codes where we are only interested in the performance of the error correction encoders (we are not interested in the error-correction decoder or error-correction codes).

Your task will be speeding up the current implementations based on Reed-Solomon and Reed-Muller codes:

The coding will be in Python/Sagemath.
This work can accomodate multiple students.
The working language will be in English.

Environment: we collaborate with LTI. At LNT and LTI there is currently a lot of funding for research in identification. Therefore you will find a large group of people that might be available for discussion and collaboration.

Voraussetzungen

Nachrichtentechnik 2

 

Betreuer:

[security] Practical implementation of physical-layer semantic security

Stichworte:
semantic, security, secrecy, programming, implementation

Beschreibung

The goal of this project is to implement in Python/Sagemath the security functions (at least one of four) described in https://arxiv.org/abs/2102.00983
Sagemath contains libraries for mosaics, BIBDs, etc, that can be used for the project.

Motivation:
There are various types of security definitions.
The mutual information based types, in increasing order of security requirement are

  1. Weak secresy asks that the average mutual information of the eavesdropper I(M:E)/n goes to 0 for a uniform message M (average here means averaged over the blocklength n, an additional average over M is implicit in the mutual information)
  2. Strong secrecy asks that the total mutual information I(M:E) goes to 0,
  3. Semantic security asks that the total mutual informaiton I(M:E) goes to 0 for any distribution of the message M (and thus in particular for all distributions that pick any of two chosen messages with 1/2 probabilty)

Then there are the almost-equivalent respective indistiguishablity types  of security requirements (below |P-Q|_1 is the statistical distance and Exp_M is expectation value over M)

  1. average indistinguishability 1/n Exp_M | P_{E|M} - P_E |_1 for a uniform message M goes to 0 (again average refers over the blocklegth n, clearly there is also the average over M)
  2. total indistiguishability Exp_M | P_{E|M} - P_E |_1 for a uniform message M goes to 0
  3. indistinguishability |P_{E|m} - P_{E|m'}|_1 for any two messages m and m' goes to 0.

Each of the indistiguishabilities can also be written using KL digvergence instead of statistical distance, in which case the conditions are exactly equivalent to their mutual information versions.

Strong secrecy is the standard security requirement considered in information-theoretic security, while semantic security is the minimum requirement considered in computational security.
Information-theoretic (physical-layer) security differs from computational security in that the secrecy is guaranteed irrespective of the power of the adversary, while in computational security E is computationally bounded. Computational security also assumes that the message is at least of a certain length for the schemes to work, and thus if the message to be secured is too small it needs to be padded to a larger message.

In practice, information theoretic security is expensive, because the messages that can be secured can be only as long as the keys that can be generated. However, in identification only a very small part of the message needs to be secured, which in computational security triggers padding and thus waste, but on the other side makes information-theoretic security accessible and not so expensive.

At the same time, the security of identification implicitly requires semantic security. It has been known for a while that hash functions provide information-theoretic strong secrecy. However, because the standard for information-theoretic security has been strong secrecy, before https://arxiv.org/abs/2102.00983 no efficient functions where known to provide information-theoretic semantic security.
We need an implementation of these type of functions so that we can integrate information-theoretic security into our identification project.

Betreuer:

[quantum] Realignment criterion and upper bounds in device-independent QKD

Beschreibung

This paper uses the partial transpose as a tool to derive upper bounds on device-independent QKD
https://arxiv.org/abs/2005.13511
In this project the goal is to try to generalize the above to the other tools like the reallignment criterion:
https://arxiv.org/abs/quant-ph/0205017
https://arxiv.org/abs/0802.2019

Voraussetzungen

basics of quantum information/quantum formalism

Betreuer:

[quantum] Semantic security of infinite-dimensional classical-quantum channels

Beschreibung

Generalize semantic security of classical-quantum channels to infinite dimensional channel (not necessarily gaussian)

Voraussetzungen

quantum information theory

Betreuer:

[quantum] Asymptotic continuity of restricted quantum relative entropies under general channels

Stichworte:
quantum, relative entropy, Pinsker, reverse, inequality, information thoery, asymptotic, continuity

Beschreibung

Asypmtotic continuity is a property in the form of inequalities (classically known also as inequalities of the reverse-Pinker type) that is necessary to prove upper bounds on operational capacities.

The (quantum) relative entropy (also known as quantum divergence and classically also known as Kullbackt-Leibler divergence), can be used to define various entanglment measures many of which have a proven asymptotic continuity.

Of particular interest are the restricted quantum relative entropies defined by Marco Piani (https://arxiv.org/abs/0904.2705), many of which satisfy asymptotic continuity (A.S.)

In the above there are maybe 2-3 different proof styles.
We can group the results in the above as follows:

  • A.S. for entropy, conditional entropies, mutual information, conditional mutual information
  • A.S. for relative entropies with infimum over states on the second argument
  • A.S. relative entropies with infimum over state *and maximization over measurement channels*

The goal of the project is to generalize the last case to asymptotic continuity for relative entropies with infimum over state and maximization over *general* channels.

Possible new proof directions are

Voraussetzungen

Knowledge of quantum information is highly recommended/required.
Knowledge of matrix analysis will be a strong advantage.

Kontakt

roberto.ferrara@tum.de

Betreuer:

[quantum] Practical protocols for quantum synchronization in classical network

Stichworte:
quantum, network, synchronization

Beschreibung

Voraussetzungen

Knowledge of quantum theory as provided by the course Algorithms in Quantum Theory or similar

Betreuer:

[quantum] Entanglement-measures upper bounds on device-independent distillable key

Stichworte:
quantum, qkd, entanglement

Beschreibung

The goal of this work is to try to upper bound the device-independent distillable key in terms of locally restricted relative entropy of entanglement (an entanglement measure).

The following are relevant works/articles

Voraussetzungen

Strong background in quantum theory is required, preferably in quantum information theory, which is not covered by the course Algorithms in Quantum Theory

Betreuer:

Forschungspraxis (Research Internships)

Preventing Malicious Updates in the Messaging Layer Security using Commutative Encryption

Beschreibung

Regular secure communication protocols (as the Signal protocol, the double ratchet algorithm) are not well adapted to big groups.   The Messaging Layer Security is a security layer for end-to-end encrypting messages in arbitrarily sized groups. It is based on a Merkle tree structure, where leaf nodes are the group members. Non-leaf do not represent any entity but exist in the group representation of all group members. To each node in the tree corresponds a private/public key-pair. Leaf nodes (i.e. group members) know the key-pairs of all their ascending nodes.   Each leaf node applies the same key derivation function on the root private key to generate the same symmetric key used for communication. At every epoch, a key update is launched by a group member (leaf node): the leaf node first updates its own key-pair arbitrarily; then it only updates all of its ascending nodes' key-pairs in the following way: each node's new key-pair is obtained by deriving it from its child node. The leaf node has to communicate those new key-pairs to the other leaf nodes that share ascendants. If the updating node is malicious, it could communicate inconsistent information to different leaf nodes, thus effectively kicking them out of the group.   The aim of the internship is to explore the use of commutative encryption in preventing malicious updates in MLS. Specifically, the goals are:
1. Make a state of the art on commutative encryption.
2. Prove the prevention of malicious updates using commutative encryption.

Betreuer:

Nonlinear Effects in Multi-Core Fibers

Stichworte:
nonlinearity, optical communications, mcf, multicore fibers

Beschreibung

Space-division multiplexing (SDM), which consists in exploiting multimode fibers (MMFs) or multicore fibers (MCFs) instead of single mode ones, is one of the future optical communications architectures to increase data rates and network planning flexibility. The nonlinear properties of MCFs are of primary interest in assessing the usefulness of SDM against the current network. With this thesis, the student has the chance to work on a state-of-the-art topic in the field of optical communication systems, and progress quickly thanks to a tight (if desired) supervision. Would you be curious to know more about it? If so, just get in touch with me at paolo.carniello@tum.de (personal page https://www.ce.cit.tum.de/lnt/mitarbeiter/doktoranden/carniello/).

Voraussetzungen

-some knowledge on optical communications systems (e.g., Optical Communication Systems or Simulation of Optical Communication Systems Lab)

-some knowledge about communications engineering topics

Kontakt

paolo.carniello@tum.de
See https://www.ce.cit.tum.de/lnt/mitarbeiter/doktoranden/carniello/ for more info on the supervisor.

Betreuer:

Strong Coupling Multimode Fibers

Stichworte:
Multimode fibers, Space-division multiplexing

Beschreibung

Space-division multiplexing (SDM), which consists in exploiting multimode (MMF) or multicore fibers instead of single mode ones, is one of the future architectures to increase data rates and network planning flexibility. A desired working condition for SDM is the so called strong-coupling linear regime, which is however not intrinsically achievable in common MMFs. With this topic, the student has the chance to investigate if it would be achievable with some new design. If you are curious about it, just send a mail to paolo.carniello@tum.de.

Voraussetzungen

Basics of Optical Communication Systems (see https://www.ce.cit.tum.de/en/lnt/teaching/lectures/optical-communication-systems/)

Kontakt

paolo.carniello@tum.de

Betreuer:

Neural Network-Based Signal Predistortion for Direct Detection Systems

Beschreibung

During the internship, the student will be researching the application of Neural Network-based signal predistortion to mitigate the effects of fiber chromatic dispersion in direct detection systems.

Voraussetzungen

  • basic Python skills beneficial

Betreuer:

Resilient Over-the-Air Computation with Applications in Federated Learning

Kurzbeschreibung:
Over-the-Air (OtA) computation is a promising approach with the potential to drastically reduce the communication overhead of wireless distributed data-processing systems (e.g. Federated Learning). Since this method is prone to adversarial noise, it is crucial to secure it against jamming attacks.

Beschreibung

Novel use cases for mobile communication networks include the aggregation of large amounts of data, which is stored in a distributed manner across network users. For instance, Federated Learning requires the aggregation of machine learning model updates from contributing users.

Over-the-Air (OtA) computation is an approach with the potential to drastically reduce the communication overhead of wireless distributed data-processing systems (e.g. Federated Learning). It exploits the multiple-access property and linearity of the wireless channel to compute sums of pre-processed data by the channel. This important property at the same time opens great opportunities for adversaries to corrupt the computation process. Therefore, Increasing the resiliency of OtA computation systems against adversaries is important.

Several solutions [1-4] have been proposed to tackle this problem, which make different assumptions and impose different constraints on the system. These solutions shall be evaluated and compared, theoretically as well as empirically by a simple Federated Learning implementation.

 

[1] X. Fan, Y. Wang, Y. Huo, and Z. Tian, “BEV-SGD: Best Effort Voting SGD Against Byzantine Attacks for Analog-Aggregation-Based Federated Learning Over the Air,” IEEE Internet of Things Journal, vol. 9, no. 19, pp. 18946–18959, Oct. 2022.

[2] S. Park and W. Choi, “Byzantine Fault Tolerant Distributed Stochastic Gradient Descent Based on Over-the-Air Computation,” IEEE Transactions on Communications, vol. 70, no. 5, pp. 3204–3219, May 2022,

[3] S. Huang, Y. Zhou, T. Wang, and Y. Shi, “Byzantine-Resilient Federated Machine Learning via Over-the-Air Computation,” arXiv:2105.10883 [cs, math], May 2021, Accessed: Dec. 21, 2021

[4] H. Sifaou and G. Y. Li, “Robust Federated Learning via Over-the-Air Computation,” in 2022 IEEE 32nd International Workshop on Machine Learning for Signal Processing (MLSP), Aug. 2022.

 

Voraussetzungen

- knowledge in statistics and estimation theory
- basic knowledge of machine learning with Tensorflow

Betreuer:

[identification] Idnetification and Secrecy with Physically-Unclonable-Functions (PUFs)

Stichworte:
PUF secrecy identification

Beschreibung

Identification is a communication scheme that allows rate doubly exponential in the blocklemght, with the tradeoff that identities cannot be decoded (as messages do) but can only be verified.

Identification codes can be achieved by first removing the errors from the channel with regular transmission channel coding, and then sending a challenge though the corrected channel. For every identity i, The channenge is generated by picking a random input m and computing the corresponding output T_i(m) using a function T_i that depends on the identity. The challenge is then the pair m,T_i(m) and the receiver wanting to verify an identity j will verify whether j=i by testing the challenge. This is done by recomputing the output with T_j and verifying whether T_j(m)= T_i(m). The errors are reduced by ensuring that the various functions collide on a small fraction of the possible inputs.

It turns out that choosing good sets of funtions {T_i} is the same as choosing error-correction codes {c_i} with large distance, where now each codeword c_i defines a function by mapping positions m (sometimes called code locators) to symbols c_im of the codeword.
We can thus construct identification codes by choosing error-correction codes where we are only interested in the performance of the error correction encoders (we are not interested in the error-correction decoder or error-correction codes).

From previous work we have a fairly efficient implementation based Reed-Muller code which can be found at

Secrecy in this identification codes has also been implemented in unpublished work. Furthermore, the theoretical work on Identification with PUF's has been done in

The goal of the project will be to bridge the three topics and create practical and efficient secret identification codes in the PUF setting.

The working language will be in English.

Environment: this is a project in collaboration with LTI. At LNT and LTI there is currently a lot of funding for research in identification. Therefore you will find a large group of people that might be available for discussion and collaboration.

Betreuer:

MAB-Based Efficient Distributed ML on the Cloud

Stichworte:
Distributed Machine Learning (ML), Multi-Armed Bandits (MABs), Cloud Simulations (AWS, GCP, ...)

Beschreibung

We consider the problem of running a distributed machine learning algorithm on the cloud. This imposes several challenges. In particular, cloud instances may have different performances/speeds. To fully leverage the performance of the instances, we want to characterize their speed and potentially use the fastest ones. To explore the speed of the instances while exploiting them (assigning computational tasks), we use the theory of multi-armed bandits (MABs).

The goal of the research intership is to start by implementing existing theoretical algorithms [1] and possibly adapting them based on the experimental observations.

[1] M. Egger, R. Bitar, A. Wachter-Zeh and D. Gündüz, Efficient Distributed Machine Learning via Combinatorial Multi-Armed Bandits, submitted to IEEE Journal on Selected Areas in Communications (JSAC), 2022.

Voraussetzungen

  • Information Theory
  • Machine Learning Basics
  • Python (Intermediate Level)

Betreuer:

[quantum] Quantum Machine Learning for Communication

Stichworte:
physical, layer, quantum, machine learning, non-linear

Beschreibung

As part of an ongoing project with Huawei we are looking into quantum machine learning algorithms applied to decoding at the end of an optical fiber in the non-linear regime.

So far we have tried only the quantum version of k-mean clustering, however the goal is to test further quantum algorithms, in particular quantum support vector machines next, and their classical quantum-inspired counterpart.

The projects will involve reading the literature on quantum machine learning algorithms and quantum-inspired algorithms, find or come up with an implementation (this will involve the use of quantum libraries, in particular so far we have use qiskit), and benchmark the performance.

Voraussetzungen

Knowledge of quantum mechanics or quantum information is highly recommended.

Betreuer:

[identification] Implementation of identification with universal hash functions

Stichworte:
universal hash identification

Beschreibung

Identification is a communication scheme that allows rate doubly exponential in the blocklemght, with the tradeoff that identities cannot be decoded (as messages do) but can only be verified.

The double exponential growth presents various challenges in the finite regime: there are heavy computational costs introduced at the encoder and decoder and heavy trade-offs between the error and the codes sizes.

The ultimate goal is to find a fast, reliable implementation while still achieving large code sizes.

Identification codes can be achieved by first removing the errors from the channel with regular transmission channel coding, and then sending a challenge though the corrected channel. For every identity i, The channenge is generated by picking a random input m and computing the corresponding output T_i(m) using a function T_i that depends on the identity. The challenge is then the pair m,T_i(m) and the receiver wanting to verify an identity j will verify whether j=i by testing the challenge. This is done by recomputing the output with T_j and verifying whether T_j(m)= T_i(m). The errors are reduced by ensuring that the various functions collide on a small fraction of the possible inputs.

It turns out that choosing good sets of funtions {T_i} is the same as choosing error-correction codes {c_i} with large distance, where now each codeword c_i defines a function by mapping positions m (sometimes called code locators) to symbols c_im of the codeword.
We can thus construct identification codes by choosing error-correction codes where we are only interested in the performance of the error correction encoders (we are not interested in the error-correction decoder or error-correction codes).

Your task will be implementing the identification codes described in

aiming at the fastest implementation, and testing their performance in comparison to other current implementations.

For reference, our previous work on identification based on Reed-Solomon and Reed-Muller code can be found at

The coding will be in Python/Sagemath.
The working language will be in English.

Environment: we collaborate with LTI. At LNT and LTI there is currently a lot of funding for research in identification. Therefore you will find a large group of people that might be available for discussion and collaboration.

Betreuer:

[identification] Simulation and performance improvement of identification codes

Beschreibung

Identification is a communication scheme that allows rate doubly exponential in the blocklemght, with the tradeoff that identities cannot be decoded (as messages do) but can only be verified.

The double exponential growth presents various challenges in the finite regime: there are heavy computational costs introduced at the encoder and decoder and heavy trade-offs between the error and the codes sizes.

The ultimate goal is to find a fast, reliable implementation while still achieving large code sizes.

Identification codes can be achieved by first removing the errors from the channel with regular transmission channel coding, and then sending a challenge though the corrected channel. For every identity i, The channenge is generated by picking a random input m and computing the corresponding output T_i(m) using a function T_i that depends on the identity. The challenge is then the pair m,T_i(m) and the receiver wanting to verify an identity j will verify whether j=i by testing the challenge. This is done by recomputing the output with T_j and verifying whether T_j(m)= T_i(m). The errors are reduced by ensuring that the various functions collide on a small fraction of the possible inputs.

It turns out that choosing good sets of funtions {T_i} is the same as choosing error-correction codes {c_i} with large distance, where now each codeword c_i defines a function by mapping positions m (sometimes called code locators) to symbols c_im of the codeword.
We can thus construct identification codes by choosing error-correction codes where we are only interested in the performance of the error correction encoders (we are not interested in the error-correction decoder or error-correction codes).

Your task will be speeding up the current implementations based on Reed-Solomon and Reed-Muller codes:

The coding will be in Python/Sagemath.
This work can accomodate multiple students.
The working language will be in English.

Environment: we collaborate with LTI. At LNT and LTI there is currently a lot of funding for research in identification. Therefore you will find a large group of people that might be available for discussion and collaboration.

Voraussetzungen

Nachrichtentechnik 2

 

Betreuer:

[quantum] Realignment criterion and upper bounds in device-independent QKD

Beschreibung

This paper uses the partial transpose as a tool to derive upper bounds on device-independent QKD
https://arxiv.org/abs/2005.13511
In this project the goal is to try to generalize the above to the other tools like the reallignment criterion:
https://arxiv.org/abs/quant-ph/0205017
https://arxiv.org/abs/0802.2019

Voraussetzungen

basics of quantum information/quantum formalism

Betreuer:

Seminar Themen

Die drei Seminare "Seminar on Coding and Cryptography", "Seminar on Digital Communications" und "Seminar on Optical Communications" werden zusammen organisiert und abgehalten.

Mehr Informationen finden Sie unter Seminar Themen.