TY - CHAP A1 - Völker, Timo A1 - Volodina, Ekaterina A1 - Tüxen, Michael A1 - Rathgeb, Erwin Paul T1 - A QUIC Simulation Model for INET and its Application to the Acknowledgment Ratio Issue T2 - 2020 IFIP Networking Conference N2 - Quick UDP Internet Connections (QUIC) is a novel transport protocol introducing known features in a new protocol design. To investigate these features and the design, we developed a QUIC implementation in the INET simulation model suite. In this paper, we describe that implementation, its validation and a result achieved using the simulation model. The result shows the negative impact on throughput, when raising the acknowledgment ratio. We propose a solution and describe how it solves the issue. KW - QUIC KW - INET OMNeT++ KW - Protocol Simulation KW - Transport Protocol KW - Ack Ratio Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-149662 UR - https://ieeexplore.ieee.org/document/9142723 SN - 978-3-903176-28-7 SP - 737 EP - 742 PB - IEEE CY - New York, NY, USA ER - TY - CHAP A1 - Horsthemke, Ludwig A1 - Bischoff, Christian A1 - Glösekötter, Peter A1 - Burchard, Bernd A1 - Staacke, Robert A1 - Meijer, Jan T1 - All optical readout scheme for photoluminescence based magnetic field sensors T2 - 2020 IEEE Sensors, Rotterdam, Netherlands N2 - An improvement on a concept for all optical mag- netometry using nitrogen vacancies in diamond is presented. The concept is based on the fluorescence attenuation of optically pumped nitrogen vacancies by magnetic fields up to ≈ 50 mT. The attenuation is registered by modulating the pumping power to generate a constant signal at a photodetector. A sensitivity of 2.6μT/√Hz at a sampling frequency of 500 Hz is achieved. KW - photoluminescence based magnetic field sensors Y1 - 2020 U6 - http://dx.doi.org/10.1109/SENSORS47125.2020.9278923 SP - 1 EP - 3 ER - TY - CHAP A1 - Willing, Markus A1 - Dresen, Christian A1 - Haverkamp, Uwe A1 - Schinzel, Sebastian T1 - Analyzing medical device connectivity and its effect on cyber security in german hospitals N2 - Background: Modern healthcare devices can be connected to computer networks and many western healthcareinstitutions run those devices in networks. At the same time, cyber attacks are on the rise and there is evidence thatcybercriminals do not spare critical infrastructure such as major hospitals, even if they endanger patients. Intuitively,the more and closer connected healthcare devices are to public networks, the higher the risk of getting attacked. Methods: To asses the current connectivity status of healthcare devices, we surveyed the field of German hospitalsand especially University Medical Center UMCs. Results: The results show a strong correlation between the networking degree and the number of medical devices.The average number of medical devices is 25.150, with a median of networked medical devices of 3.600. Actual keyusers of networked medical devices are the departments Radiology, Intensive Care, Radio-Oncology RO, NuclearMedicine NUC, and Anaesthesiology in the group of UMCs. In the next five years, the usage of networked medicaldevices will increase significantly in the departments of Surgery, Intensive Care, and Radiology. We detected a strongcorrelation between the degree of connectivity and the likelihood of being attacked.The survey answers regarding the cyber security status reveal a lack of security basics in some of the inquiredhospitals. We did discover successful attacks in hospitals with separated or subsidiary departments. A fusion ofcompetencies on an organizational level facilitates the right behavior here. Most hospitals rated themselvespredominantly positively in the self-assessment but also stated the usefulness of IT security insurance.Conclusions:Concluding our results, hospitals are already facing the consequences of omitted measures within theirgrowing pool of medical devices. Continuously relying on historically grown structures without adaption and trustingmanufactures to solve vectors is a critical behavior that could seriously endanger patients. Y1 - 2020 U6 - http://dx.doi.org/10.1186/s12911-020-01259-y PB - BMC Medical Informatics and Decision Making volume ER - TY - CHAP A1 - Müller, Jens A1 - Ising, Fabian A1 - Mla­de­nov, Vla­dis­lav A1 - Mainka, Chris­ti­an A1 - Schinzel, Sebastian A1 - Schwenk, Jörg T1 - Of­fice Do­cu­ment Se­cu­ri­ty and Pri­va­cy T2 - 14th USE­NIX Work­shop on Of­fen­si­ve Tech­no­lo­gies (WOOT 2020) N2 - OOXML and ODF are the de facto standard data formats for word processing, spreadsheets, and presentations. Both are XML-based, feature-rich container formats dating back to the early 2000s. In this work, we present a systematic analysis of the capabilities of malicious office documents. Instead of focusing on implementation bugs, we abuse legitimate features of the OOXML and ODF specifications. We categorize our attacks into five classes: (1) Denial-of-Service attacks affecting the host on which the document is processed. (2) Invasion of privacy attacks that track the usage of the document. (3) Information disclosure attacks exfiltrating personal data out of the victim's computer. (4) Data manipulation on the victim's system. (5) Code execution on the victim's machine. We evaluated the reference implementations – Microsoft Office and LibreOffice – and found both of them to be vulnerable to each tested class of attacks. Finally, we propose mitigation strategies to counter these attacks. KW - Cyber Security KW - Open Document Format KW - docx Y1 - 2020 UR - https://www.usenix.org/conference/woot20/presentation/muller PB - USENIX ER - TY - CHAP A1 - Müller, Jens A1 - Brinkmann, Marcus A1 - Poddebniak, Damian A1 - Schinzel, Sebastian A1 - Schwenk, Jörg T1 - Mailto: Me Your Secrets. On Bugs and Features in Email End-to-End Encryption T2 - 2020 IEEE Conference on Communications and Network Security (CNS) N2 - OpenPGP and S/MIME are the two major standards for email end-to-end encryption. We show practical attacks against both encryption schemes in the context of email. First, we present a design flaw in the key update mechanism, allowing a third party to deploy a new key to the communication partners. Second, we show how email clients can be tricked into acting as an oracle for decryption or signing by exploiting their functionality to auto-save drafts. Third, we demonstrate how to exfiltrate the private key, based on proprietary mailto parameters implemented by various email clients. An evaluation shows that 8 out of 20 tested email clients are vulnerable to at least one attack. While our attacks do not target the underlying cryptographic primitives, they raise concerns about the practical security of OpenPGP and S/MIME email applications. Finally, we propose countermeasures and discuss their advantages and disadvantages. KW - Cyber Security KW - PGP KW - S/MIME Y1 - 2020 U6 - http://dx.doi.org/10.1109/CNS48642.2020.9162218 SP - 1 EP - 9 ER - TY - CHAP A1 - Saatjohann, Christoph A1 - Ising, Fabian A1 - Krings, Luise A1 - Schinzel, Sebastian T1 - STALK: security analysis of smartwatches for kids T2 - ARES 2020: The 15th International Conference on Availability, Reliability and Security / Editors: Melanie Volkamer, Christian Wressnegger N2 - Smart wearable devices become more and more prevalent in the age of the Internet of Things. While people wear them as fitness trackers or full-fledged smartphones, they also come in unique versions as smartwatches for children. These watches allow parents to track the location of their children in real-time and offer a communication channel between parent and child. In this paper, we analyzed six smartwatches for children and the corresponding backend platforms and applications for security and privacy concerns. We structure our analysis in distinct attacker scenarios and collect and describe related literature outside academic publications. Using a cellular network Man-in-the-Middle setup, reverse engineering, and dynamic analysis, we found several severe security issues, allowing for sensitive data disclosure, complete watch takeover, and illegal remote monitoring functionality. KW - Security KW - Privacy Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-123548 SN - 978-1-4503-8833-7 SP - 1 EP - 10 ER - TY - CHAP A1 - Horsthemke, Ludwig A1 - Staake, Robert A1 - Burchard, Bernd A1 - Meijer, Jan A1 - Bischoff, Christian A1 - Glösekötter, Peter T1 - Highly Sensitive Compact Room Temperature Quantum Scalar Magnetormeter T2 - SMSI 2020 N2 - Magnetometry with nitrogen–vacancy (NV) defects in diamond has been extensively stud-ied in the past [1]. While most approaches in-clude the use of microwaves (MW) for the de-tection of electron spin resonance, only few investigate the sensitivity of the photolumines-cence (PL) from NV centers to an external magnetic field without MW [2, 3, 4]. This work aims to utilize this effect to build a highly sensi-tive and compact room temperature magne-tometer. The avoidance of MW serves the re-duction of production costs and allows a com-mercialization at the current patent situation. KW - Highly Sensitive Y1 - 2020 U6 - http://dx.doi.org/10.5162/SMSI2020/A1.4 SP - 47 EP - 48 ER - TY - CHAP A1 - Dresen, Christian A1 - Ising, Fabian A1 - Poddebniak, Damian A1 - Kappert, Tobias A1 - Holz, Thorsten A1 - Schinzel, Sebastian ED - Zhou, Jianying T1 - CORSICA: Cross-Origin Web Service Identification T2 - The 15th ACM ASIA Conference on Computer and Communications Security N2 - Vulnerabilities in private networks are difficult to detect for attackers outside of the network. While there are known methods for port scanning internal hosts that work by luring unwitting internal users to an external web page that hosts malicious JavaScript code, no such method for detailed and precise service identification is known. The reason is that the Same Origin Policy (SOP) prevents access to HTTP responses of other origins by default. We perform a structured analysis of loopholes in the SOP that can be used to identify web applications across network boundaries. For this, we analyze HTML5, CSS, and JavaScript features of standard-compliant web browsers that may leak sensitive information about cross-origin content. The results reveal several novel techniques, including leaking JavaScript function names or styles of cross-origin requests that are available in all common browsers. We implement and test these techniques in a tool called CORSICA. It can successfully identify 31 of 42 (74%) of web services running on different IoT devices as well as the version numbers of the four most widely used content management systems WordPress, Drupal, Joomla, and TYPO3. CORSICA can also determine the patch level on average down to three versions (WordPress), six versions (Drupal), two versions (Joomla), and four versions (TYPO3) with only ten requests on average. Furthermore, CORSICA is able to identify 48 WordPress plugins containing 65 vulnerabilities. Finally, we analyze mitigation strategies and show that the proposed but not yet implemented strategies Cross-Origin Resource Policy (CORP)} and Sec-Metadata would prevent our identification techniques. Y1 - 2020 UR - https://asiaccs2020.cs.nthu.edu.tw/program/ ER -