We investigate the effectiveness of anti-phishing support systems through a quantitative study involving 453 participants. To this end, we developed a tool that allows participants to immerse themselves in a realistic setting, tasked with classifying emails as either phishing or legitimate, while being assisted by support systems. Despite the prevalence of support systems in webmailers and email clients, our results indicate no significant difference in correctly assessing emails of varying difficulty between these systems and the control group. We found a minor negative effect of the support system that uses tooltips compared to other support systems. In the subsequent survey, we found that the support systems are appreciated and considered helpful by users, as supported by the results of the UEQ-S, even if they have no observable effect. Email context, such as the contact list, as well as hovering over the links, had stronger effects on the classification than the tested support systems.

E-mail phishing attacks remain one of the most significant challenges in IT security and are often used for initial access. Many organizations rely on phishing simulations to educate their staff to recognize suspicious e-mails. Previous studies have analyzed the effectiveness of these phishing simulations with mixed findings. However, the perception of and attitudes towards phishing simulations among staff have received little to no attention. This paper presents findings from a study that we carried out in cooperation with a multinational company that conducted phishing simulations over more than 12 months. We first conducted a quantitative survey involving 757 employees and then qualitative interviews with 22 participants to gain deeper insights into the perception of phishing simulations and the corresponding e-learning. We could not find evidence that employees feel attacked by their organization, as previous studies suspected. On the contrary, we found that a majority 86.9 % have a positive or very positive attitude towards phishing simulations. The interviews revealed that some employees developed new routines for e-mail processing, but most describe themselves as having become more vigilant without concrete changes. Furthermore, we found evidence that phishing simulations create a false sense of security, as the employees feel protected by them. Additionally, a lack of communication and feedback can negatively impact employees' attitudes and lead to adverse consequences. Finally, we show that only a small portion of the employees who clicked on the phishing website interacted with the interactive e-learning elements, which raises questions about its objective usefulness, although they are perceived as useful.

Contact Tracing Apps (CTAs) have been developed to contain the coronavirus disease 19 (COVID-19) spread. By design, such apps invade their users’ privacy by recording data about their health, contacts, and—partially—location. Many CTAs frequently broadcast pseudorandom numbers via Bluetooth to detect encounters. These numbers are changed regularly to prevent individual smartphones from being trivially trackable. However, the effectiveness of this procedure has been little studied.

Tor is a popular privacy-enhancing technology that allows anonymous communication using onion routing. However, such technologies are only helpful if used; therefore, performance is an important aspect. One of the main performance bottlenecks of Tor is the cross-circuit interference (CCI) problem. Tor multiplexes multiple circuits over a single Transport Layer Security (TLS) 1.2 connection if they share a path segment (link). Therefore, they have the same congestion window, which can yield unfair bandwidth allocation. However, there has been little work in understanding this problem in more depth. This paper investigates the number of simultaneously shared links in the current Tor network, which are the root cause of CCI. We developed a novel shared links simulator called SALSA to investigate this problem. Our results show that 3.7 % of active links are shared, and the involving Onion Routers (ORs) have the most common bandwidth capabilities. Additionally, we show that the internal circuits and exit policy influence the CCI problem. Furthermore, we model the number of shared links when the demand grows further and show that the number of shared links can go up to 16 %. Finally, we run Shadow simulations with a 25 % down-scaled Tor network and show that a network without shared links is faster.

The main objectives of the Intelligent Transportation Systems (ITS) vision is to improve road safety, traffic management, and mobility by enabling cooperative communication among participants. This vision requires the knowledge of the current state of the road traffic, which can be obtained by collecting Floating Car Data (FCD) information using Dedicated Short-Range Communication (DSRC) based on the IEEE 802.11p standard. Most of the existing FCD collection protocols have been evaluated via simulations and mathematical models, while the real-world implications have not been thoroughly investigated. This paper presents an open-source implementation of two state-of-the-art FCD collection algorithms, namely BASELINE and DISCOVER. These algorithms are implemented in an open-source vehicular prototyping platform and validated in a real-world experimental setup.

peer reviewed

Active measurement studies show that the Peer-to-Peer (P2P) file sharing protocol Bit Torrent is highly under attack. Moreover, malicious peers can easily exploit the original seeding algorithm and therefore reduce the efficiency of this protocol. In this paper, we propose a novel seeding algorithm that requests peers to vote for their best sharing peers. Our results show that this incentive mechanism makes Bit Torrent harder to exploit without losing performance. In some situations our algorithm even outperform other seeding algorithms. The peer exchange - that comes as a side effect - reduces the dependency on a centralized tracker and increases the robustness and the efficiency. We studied the effectiveness of our approach in a real testbed comprising 32 peers.

Since most real-time audio and video applications lack of QoS support, QoS demand of such IP data streams shall be detected and applied automatically. To support QoS in LANs, especially in home environments, a system was developed, which enables self-organised QoS for unmanaged networks through host implementations in contrast to traditional solutions without network support. It supports per-link reservation and prioritisation and works without a need for application support. One part of this system is an automated traffic identification and classification system, which is subject of this paper. An efficient set of attribute meters, based on the Statistical Protocol IDentification (SPID), was investigated, enhanced and evaluated. We improved the performance, added support for UDP protocols and real-time identification. It is shown that using our implementation efficient near real-time protocol identification on per-flow basis is possible to support self-organised resource reservation.