Chalmers Open Digital Repository

Välkommen till Chalmers öppna digitala arkiv!

Här hittar du:

Studentarbeten utgivna på lärosätet, såväl kandidatarbeten som examensarbeten på grund- och masternivå
Digitala specialsamlingar, som t ex Chalmers modellkammare
Utvalda projektrapporter

Forskningspublikationer, rapporter och avhandlingar hittar du i research.chalmers.se

Enheter i Chalmers ODR

Välj en enhet för att se alla samlingar.

Visar 1 - 2 av 2

Senast publicerade

Deep Learning-Assisted Differential Cryptanalysis on Round-reduced Block Ciphers: What are the advantages?
(2026) Flink, Lucas
This thesis investigates and evaluates the application of deep learning techniques in differential cryptanalysis of lightweight block ciphers. The main two focuses are on comparison between a hybrid attack pipeline and a classical attack pipeline, and on transfer learning compared to training a model from scratch. The study considers both SPN ciphers and the SIMON32/64 cipher, which is part of the ISO standard for RFID systems. Neural distinguishers based on convolutional neural networks are trained to classify pairs of ciphertexts, as either random noise or ciphertexts produced by the cipher. For the SPN cipher it is integrated into a key recovery attack pipeline. For SIMON32/64 it is compared to the outcome of transfer learning of a pre-trained network. The results show that a hybrid approach is comparable to a classical approach in terms of key recovery attack. The transfer learning enables faster convergence, but does not reach the same accuracy in classification compared to training the model from scratch. These findings contribute to the understanding of the role of machine learning in cryptanalysis, and how it can be further studied to potentially be more useful in the future, and what the security impacts might be for real-world use in especially supply chains using RFID technology.
Evaluating VPN Defenses Against Video Fingerprinting: A Case Study of DAITA
(2026) Henriksson, Wilhelm; Liman, Max
Virtual Private Networks aim to obfuscate and hide the user’s internet traffic by encrypting it and rerouting it through the service providers own servers. This is no longer enough since by examining the frequency and size of the packets sent over the network, an attacker can with the help of a database of fingerprinted videos from different streaming services correctly identify which video is being streamed, despite a VPN connection being active. The VPN company Mullvad has developed a feature called DAITA for their service aiming to solve this issue through various methods. In this paper, a type of fingerprinting attack on video data that was developed by the authors of “Endangered Privacy: Large-Scale Monitoring of Video Streaming Services” is used. The attack exploits the information leak of modern video streaming protocols which are patterns that are referred to as “bursts”. These bursts are unique and can be mapped to fingerprints of specific videos. This paper aims to examine how the DAITA feature and other defensive measures affect the given video fingerprinting attack’s performance and evaluate the data derived from the tests of the attack on these different protections. We find that the attack works against the regular use of VPN as expected, and that the padding of packets is not what breaks the attack. The attack will still work so long as the traffic is translatable into bursts and similar enough to the fingerprints. When a VPN connection with DAITA enabled has a defense active that is able to disrupt the traffic pattern enough to confuse the bursts from the fingeprints, the attack fails. However, we show that DAITA does not always break the attack.
Rotation-Symmetric Bosonic Code Error Correction: Investigating error-correcting capabilities of the Two-Mode Binomial Code
(2025) Andersson, Julius; Hiscoke, Griffin; Svensson, Carl; Zou, Hang
This project investigates the error-correcting capabilities of the Two-Mode Binomial Code, a subclass of Rotation-Symmetric Bosonic (RSB) codes designed to mitigate the trade-off between protection against photon loss and dephasing noise. The project focuses exclusively on the ability of the code to correct photon loss errors. While the Knill-Laflamme (KL) conditions for this code are known to be satisfied to the first order in the photon decay rate, its behavior at higher orders has not been previously established. We derive the two-mode photon loss error operators to the second order in κt and evaluate the satisfaction of the KL conditions for code parameters K = 2 with symmetry orders N = 2 and N = 4. By utilizing a cost function to quantify the violation of these conditions, our results demonstrate that the KL conditions are not strictly satisfied for either symmetry order. However, the N = 4 code shows a higher degree of satisfaction compared to N = 2, with optimal beam-splitter parameters found at δ = π/4 and 3π/4. This corresponds to the values required for first-order dephasing correction. These findings indicate that while exact error correction is not feasible to the second order, the N = 4 Two-Mode Binomial Code remains a promising candidate for use with approximate recovery channels such as teleportation or the Petz Recovery Map.
Motion-Capture Comparison of Unilateral and Bilateral Knee Orthoses in Orthopedic Rehabilitation
(2026) Avdic, Edin; Razaie, Elias
This thesis examines the contribution of orthosis, between having unilateral (support on one side of the knee) orthoses compared to bilateral (support on both sides of the knee orthoses, to a patient's rehabilitation process following knee-related orthopedic injuries. Such as muscle weakness, anterior cruciate ligament (ACL) injuries, or impaired bone function resulting from surgical procedures or neurological diseases. Since ethical guidelines restrict the use of patients with knee-related orthopedic injuries in this research. Therefore, only healthy subjects were recruited, and all tasks were within the normal range of motion. The analysis was done with Optical Motion Capture and biomechanical properties, allowing for a detailed analysis of the orthoses. The orthosis with support on both sides of the knee was the more stable option in 10 out of 12 comparisons. The results point to a clear trend: that the two-sided support is the most effective option in terms of control and stability. This research provides insight into how well the orthoses contribute to rehabilitation and the potential it has in optimization of medical applications.
Early phase evaluation of building wind interaction for structural design
(2025) Grampp, Axel
Wind is a major horizontal force on structures. Due to its complex and highly variable behaviour, reliance on design codes such as Eurocode 1991-1-4 is necessary for predicting wind effects. However, such codes cannot fully account for all, infinitely variable types of structures and their resulting aerodynamic responses. The dominant alternative, wind-tunnel testing, provides detailed results but remains costly and time-consuming. In parallel, Computational Fluid Dynamics (CFD) has gained increasing credibility as a complementary approach for wind analysis. This thesis explores the application of IBOFlow, an in-house CFD flow-solver developed by Fraunhofer-Chalmers Centre, in an structural design context. Through a validation study, IBOFlow was shown to achieve favorable prediction performance and overall agreement with benchmark wind-tunnel data. Subsequently, a series of Case Studies further explored its integration into early-stage design workflows, illustrating its ability to complement code-based approaches and support early-stage design exploration. The results indicate that the integrated IBOFlow method can provide valuable predictions, while reducing the time needed for setup and calculation. The study concludes that an immersed-boundary CFD approach, when validated and integrated with design tools, can potentially offer a practical and accessible means to enhance early-phase wind assessment of complex structures for structural engineers. Keywords: