[{"status":"public","user_id":"83504","publisher":"Association for Computing Machinery","_id":"25336","page":"1647–1664","citation":{"apa":"Schwenk, J., Brinkmann, M., Poddebniak, D., Müller, J., Somorovsky, J., &#38; Schinzel, S. (2020). Mitigation of Attacks on Email End-to-End Encryption. <i>Proceedings of the 2020 ACM SIGSAC Conference on Computer and Communications Security</i>, 1647–1664. <a href=\"https://doi.org/10.1145/3372297.3417878\">https://doi.org/10.1145/3372297.3417878</a>","ieee":"J. Schwenk, M. Brinkmann, D. Poddebniak, J. Müller, J. Somorovsky, and S. Schinzel, “Mitigation of Attacks on Email End-to-End Encryption,” in <i>Proceedings of the 2020 ACM SIGSAC Conference on Computer and Communications Security</i>, 2020, pp. 1647–1664, doi: <a href=\"https://doi.org/10.1145/3372297.3417878\">10.1145/3372297.3417878</a>.","short":"J. Schwenk, M. Brinkmann, D. Poddebniak, J. Müller, J. Somorovsky, S. Schinzel, in: Proceedings of the 2020 ACM SIGSAC Conference on Computer and Communications Security, Association for Computing Machinery, New York, NY, USA, 2020, pp. 1647–1664.","chicago":"Schwenk, Jörg, Marcus Brinkmann, Damian Poddebniak, Jens Müller, Juraj Somorovsky, and Sebastian Schinzel. “Mitigation of Attacks on Email End-to-End Encryption.” In <i>Proceedings of the 2020 ACM SIGSAC Conference on Computer and Communications Security</i>, 1647–1664. CCS ’20. New York, NY, USA: Association for Computing Machinery, 2020. <a href=\"https://doi.org/10.1145/3372297.3417878\">https://doi.org/10.1145/3372297.3417878</a>.","mla":"Schwenk, Jörg, et al. “Mitigation of Attacks on Email End-to-End Encryption.” <i>Proceedings of the 2020 ACM SIGSAC Conference on Computer and Communications Security</i>, Association for Computing Machinery, 2020, pp. 1647–1664, doi:<a href=\"https://doi.org/10.1145/3372297.3417878\">10.1145/3372297.3417878</a>.","ama":"Schwenk J, Brinkmann M, Poddebniak D, Müller J, Somorovsky J, Schinzel S. Mitigation of Attacks on Email End-to-End Encryption. In: <i>Proceedings of the 2020 ACM SIGSAC Conference on Computer and Communications Security</i>. CCS ’20. Association for Computing Machinery; 2020:1647–1664. doi:<a href=\"https://doi.org/10.1145/3372297.3417878\">10.1145/3372297.3417878</a>","bibtex":"@inproceedings{Schwenk_Brinkmann_Poddebniak_Müller_Somorovsky_Schinzel_2020, place={New York, NY, USA}, series={CCS ’20}, title={Mitigation of Attacks on Email End-to-End Encryption}, DOI={<a href=\"https://doi.org/10.1145/3372297.3417878\">10.1145/3372297.3417878</a>}, booktitle={Proceedings of the 2020 ACM SIGSAC Conference on Computer and Communications Security}, publisher={Association for Computing Machinery}, author={Schwenk, Jörg and Brinkmann, Marcus and Poddebniak, Damian and Müller, Jens and Somorovsky, Juraj and Schinzel, Sebastian}, year={2020}, pages={1647–1664}, collection={CCS ’20} }"},"place":"New York, NY, USA","date_updated":"2022-08-03T09:57:27Z","publication_status":"published","author":[{"full_name":"Schwenk, Jörg","first_name":"Jörg","last_name":"Schwenk"},{"first_name":"Marcus","last_name":"Brinkmann","full_name":"Brinkmann, Marcus"},{"last_name":"Poddebniak","first_name":"Damian","full_name":"Poddebniak, Damian"},{"full_name":"Müller, Jens","first_name":"Jens","last_name":"Müller"},{"full_name":"Somorovsky, Juraj","first_name":"Juraj","last_name":"Somorovsky","orcid":"0000-0002-3593-7720","id":"83504"},{"full_name":"Schinzel, Sebastian","last_name":"Schinzel","first_name":"Sebastian"}],"publication_identifier":{"isbn":["9781450370899"]},"year":"2020","title":"Mitigation of Attacks on Email End-to-End Encryption","doi":"10.1145/3372297.3417878","language":[{"iso":"eng"}],"series_title":"CCS '20","abstract":[{"lang":"eng","text":"OpenPGP and S/MIME are two major standards for securing email communication introduced in the early 1990s. Three recent classes of attacks exploit weak cipher modes (EFAIL Malleability Gadgets, or EFAIL-MG), the flexibility of the MIME email structure (EFAIL Direct Exfiltration, or EFAIL-DE), and the Reply action of the email client (REPLY attacks). Although all three break message confidentiality by using standardized email features, only EFAIL-MG has been mitigated in IETF standards with the introduction of AEAD algorithms. So far, no uniform and reliable countermeasures have been adopted by email clients to prevent EFAIL-DE and REPLY attacks. Instead, email clients implement a variety of different ad-hoc countermeasures which are only partially effective, cause interoperability problems, and fragment the secure email ecosystem.We present the first generic countermeasure against both REPLY and EFAIL-DE attacks by checking the decryption context including SMTP headers and MIME structure during decryption. The decryption context is encoded into a string DC and used as Associated Data (AD) in the AEAD encryption. Thus the proposed solution seamlessly extends the EFAIL-MG countermeasures. The decryption context changes whenever an attacker alters the email source code in a critical way, for example, if the attacker changes the MIME structure or adds a new Reply-To header. The proposed solution does not cause any interoperability problems and legacy emails can still be decrypted. We evaluate our approach by implementing the decryption contexts in Thunderbird/Enigmail and by verifying their correct functionality after the email has been transported over all major email providers, including Gmail and iCloud Mail."}],"publication":"Proceedings of the 2020 ACM SIGSAC Conference on Computer and Communications Security","department":[{"_id":"632"}],"type":"conference","keyword":["decryption contexts","EFAIL","OpenPGP","S/MIME","AEAD"],"date_created":"2021-10-04T18:58:37Z"},{"intvolume":"         4","date_updated":"2022-01-06T06:51:08Z","author":[{"last_name":"Bischoff","first_name":"Renke","full_name":"Bischoff, Renke"},{"id":"242","full_name":"Haeb-Umbach, Reinhold","last_name":"Haeb-Umbach","first_name":"Reinhold"},{"first_name":"Wolfgang","last_name":"Schulz","full_name":"Schulz, Wolfgang"},{"full_name":"Heinrichs, Guenther","first_name":"Guenther","last_name":"Heinrichs"}],"year":"2002","title":"Employment of a multipath receiver structure in a combined GALILEO/UMTS receiver","doi":"10.1109/VTC.2002.1002940","language":[{"iso":"eng"}],"main_file_link":[{"open_access":"1","url":"https://groups.uni-paderborn.de/nt/pubs/2002/BiHaScHe02.pdf"}],"abstract":[{"text":"Current navigation systems like GPS (Global Positioning System) and its Russian counterpart GLONASS (Global Navigation Satellite System) only evaluate the direct signal path. The receivers treat the reflected paths also reaching the receiver antenna as disturbance which has to be suppressed. Multipath affects the tracking accuracy by resulting in a degeneration of the S-curve of the DLL (delay locked loop). Nowadays the future European systems GALILEO and GPSIIF/III with two new signals are on the way to the market and it is time to think about new receiver structures. Therefore we investigated if it is possible to use multipath for navigation constructively.","lang":"eng"}],"publication":"IEEE 55th Vehicular Technology Conference (VTC 2002 Spring)","department":[{"_id":"54"}],"type":"conference","keyword":["combined GALILEO/UMTS receiver","delay locked loop","delay lock loops","DLL","Global Positioning System","GLONASS","GPS","GPSIIF/III","mobile satellite communication","multipath channels","multipath receiver structure","radio receivers","RAKE receiver","S-curve"],"date_created":"2019-07-12T05:27:12Z","status":"public","volume":4,"user_id":"44006","_id":"11733","page":"1844-1848 vol.4","citation":{"mla":"Bischoff, Renke, et al. “Employment of a Multipath Receiver Structure in a Combined GALILEO/UMTS Receiver.” <i>IEEE 55th Vehicular Technology Conference (VTC 2002 Spring)</i>, vol. 4, 2002, pp. 1844–48 vol.4, doi:<a href=\"https://doi.org/10.1109/VTC.2002.1002940\">10.1109/VTC.2002.1002940</a>.","bibtex":"@inproceedings{Bischoff_Haeb-Umbach_Schulz_Heinrichs_2002, title={Employment of a multipath receiver structure in a combined GALILEO/UMTS receiver}, volume={4}, DOI={<a href=\"https://doi.org/10.1109/VTC.2002.1002940\">10.1109/VTC.2002.1002940</a>}, booktitle={IEEE 55th Vehicular Technology Conference (VTC 2002 Spring)}, author={Bischoff, Renke and Haeb-Umbach, Reinhold and Schulz, Wolfgang and Heinrichs, Guenther}, year={2002}, pages={1844–1848 vol.4} }","ama":"Bischoff R, Haeb-Umbach R, Schulz W, Heinrichs G. Employment of a multipath receiver structure in a combined GALILEO/UMTS receiver. In: <i>IEEE 55th Vehicular Technology Conference (VTC 2002 Spring)</i>. Vol 4. ; 2002:1844-1848 vol.4. doi:<a href=\"https://doi.org/10.1109/VTC.2002.1002940\">10.1109/VTC.2002.1002940</a>","ieee":"R. Bischoff, R. Haeb-Umbach, W. Schulz, and G. Heinrichs, “Employment of a multipath receiver structure in a combined GALILEO/UMTS receiver,” in <i>IEEE 55th Vehicular Technology Conference (VTC 2002 Spring)</i>, 2002, vol. 4, pp. 1844–1848 vol.4.","apa":"Bischoff, R., Haeb-Umbach, R., Schulz, W., &#38; Heinrichs, G. (2002). Employment of a multipath receiver structure in a combined GALILEO/UMTS receiver. In <i>IEEE 55th Vehicular Technology Conference (VTC 2002 Spring)</i> (Vol. 4, pp. 1844–1848 vol.4). <a href=\"https://doi.org/10.1109/VTC.2002.1002940\">https://doi.org/10.1109/VTC.2002.1002940</a>","chicago":"Bischoff, Renke, Reinhold Haeb-Umbach, Wolfgang Schulz, and Guenther Heinrichs. “Employment of a Multipath Receiver Structure in a Combined GALILEO/UMTS Receiver.” In <i>IEEE 55th Vehicular Technology Conference (VTC 2002 Spring)</i>, 4:1844–48 vol.4, 2002. <a href=\"https://doi.org/10.1109/VTC.2002.1002940\">https://doi.org/10.1109/VTC.2002.1002940</a>.","short":"R. Bischoff, R. Haeb-Umbach, W. Schulz, G. Heinrichs, in: IEEE 55th Vehicular Technology Conference (VTC 2002 Spring), 2002, pp. 1844–1848 vol.4."},"oa":"1"}]