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2020
Completed
Analysis of Apple's crowdsourced location tracking system
Supervisor:
Milan Stute
2020
Completed
Wi-Fi Sharing for All: Reverse Engineering and Breaking the Apple Wi-Fi Password Sharing Protocol
Supervisor:
Milan Stute
Modern devices provide more and more functionality, simplifying everyday tasks. Obscured from the user are the complex, proprietary, and undocumented protocol stacks, most of them always listening in the background. In this thesis, we take a look at one of these features, Apple Wi-Fi Password Sharing, which enables users to share the Wi-Fi password to guests in their home. We publish documentation of involved frameworks, describe the actual protocol, and search for vulnerabilities. Besides one implementation bug, we find multiple small flaws in the protocol and user interface, which we combine into two attacks, a denial-of-service attack, which crashes the iOS settings app, and a man-in-the-middle attack, which spoofs the victim into an attacker-controlled Wi-Fi network.
2019
Completed
Analyzing Apple’s Private Wireless Communication Protocols with a Focus on Security and Privacy
Supervisor:
Milan Stute
2019
Completed
Practical Performance Analysis of Neighbor Awareness Networking
Supervisor:
Lars Almon
Milan Stute
2018
Completed
Security Aspects of the Apple Wireless Direct Link Protocol
Supervisor:
Milan Stute
2018
Completed
Desynchronization Attacks and Mitigations for the Apple Wireless Direct Link Protocol
Supervisor:
Milan Stute
2018
Completed
Draining Mallory and Sybil: DoS-resistant Disruption-Tolerant Networks
Supervisor:
Milan Stute
Description
Disruption-Tolerant Networks (DTNs) can be used as a communication means in the emergency context when communication infrastructure is unavailable. In DTNs, mobile user devices such as smartphones act as “data mules”: they store, carry and forward messages. Unfortunately, the “storing” part is especially vulnerable to denial-of-service (DoS) attacks since an attacker can flood the network with bogus information and, thus, replace or purge valid messages from a node’s buffer.
In this thesis, you will implement and evaluate a novel, DoS-resistant buffer management scheme in IBR-DTN [1], DTN implementation written in C++, which also runs on standard Android smartphones.
[1] IBR-DTN. https://github.com/ibrdtn/ibrdtn.
2018
Completed
Practical Defense Against Pollution Attacks in Network Coding-based Systems
Supervisor:
Milan Stute
Motivation
Network Coding has many positives properties that make it especially suitable for Wireless Multihop Networks [1]. Network Coding can be used to increase the effective capacity of the network, by coding (simplest form: bit-wise XOR) together packets of different flows and forwarding them in a single broadcast transmission to their intended receivers, e.g., [2]. It can also be used within a single flow to improve forward error correction (FEC) and, thus, increase transmission reliability, e.g., [3]. Unfortunately, systems based on Network Coding are easy targets for a number of attacks, and even easier to disrupt than protocols based on traditional forwarding [4].
Goal
In this thesis, you will familiarize yourself with the concept of Network Coding and analyize potential threats to both inter- and intra-flow Network Coding. Based on this, you will design and implement practical security measures. The design should then be validated against a number of different attacks.
2018
Completed
Experimental Evaluation of Mobile Attacks on Ad hoc Routing Protocols
Supervisor:
Milan Stute
2017
Completed
Understanding the Apple Auto Unlock Protocol
Supervisor:
Milan Stute
Description
Abstract of final thesis:
The Apple Watch provides the ability to automatically unlock a device running macOS when in proximity. The underlying proprietary protocol is called Auto Unlock (AU) and differs from other smart locking techniques. It uses a combination of two wireless technologies: Bluetooth Low Energy (BLE) and IEEE 802.11, to facilitate secure proximity detection. In this work we analyze the protocol by using reverse engineering and dynamic debugging. We show that AU uses both standardized protocols as well as proprietary techniques to implement a secure distance bounding protocol. With this knowledge, we discuss attack vectors and conduct a successful Man-in-the-Middle (MitM) attack on the protocol. Furthermore, we provide a starting point to allow implementations on other platforms by specifying the protocol and establish the foundation for further attacks.
2017
Completed
Reverse Engineering the Apple Wireless Direct Link Protocol
Supervisor:
Milan Stute
Flor Maria Alvarez Zurita
Apple Wireless Direct Link (AWDL) is a proprietary and undocumented 802.11 based peer-to-peer protocol. It is implemented in all of Apple's operating systems. In this thesis a reverse engineering method using binary analysis complemented by runtime analysis with traces and logs was applied. We found that each device in AWDL provides its own channel sequence. An elected master node is used to synchronize these sequences. Outside these windows of time, devices can use their wireless radio for other protocols or save energy by turning it off. Each node adapts its channel sequence, e.g. depending on network load, shifting the ratio between infrastructure and peer-to-peer Wi-Fi. This thesis also provides a first analysis of AWDL, includes the frame format documentation and presents a Wireshark dissector and a prototype implementation for AWDL.
2017
Completed
Neighbor Discovery and Maintenance under Mobility in mmWave-based Mesh Networks
Supervisor:
Daniel Steinmetzer
Milan Stute
2017
Completed
Design, Implementation and Evaluation of Realistic Scenarios and Movement Models for Natural Disasters Using Simulations for Delay Tolerant Networks
Supervisor:
Milan Stute
Max Maass
Description
Seeing the continuous increase in natural disasters around the world, many people are contemplating how to contribute helping those in need. Among them are several computer scientists who fulfil their share by developing technology which enables fast and reliable communication in disaster areas. We were inspired by their work and thus wanted to further improve the state-of-the-art. DTN is a specific technology which can be used for the creation of alternative networks in disaster areas, where conventional ones are unavailable due to the inevitable destructions implied by the disaster. Given that such technology is usually evaluated within network simulators we exclusively focus on improving the state-of-the-art of movement models and scenarios utilized within such simulators. The very random driven, and thus not realistic, state-of-the-art is improved by our contribution in the form of a fully designed, implemented, and evaluated realistic natural disaster movement model with underlying scenarios. The results of our evaluation indicate that previously published results might be too optimistic. Thus, further approximations to reality are inevitable for more accurate simulation of DTN, in the goal to ultimately obtain better and more realistic results.
2016
Completed
Energy efficient WiFi analysis framework on smartphones
Supervisor:
Milan Stute