{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,1]],"date-time":"2026-08-01T04:23:00Z","timestamp":1785558180120,"version":"3.56.0"},"reference-count":28,"publisher":"Springer Science and Business Media LLC","issue":"8","license":[{"start":{"date-parts":[[2025,12,10]],"date-time":"2025-12-10T00:00:00Z","timestamp":1765324800000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"},{"start":{"date-parts":[[2025,12,10]],"date-time":"2025-12-10T00:00:00Z","timestamp":1765324800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"}],"content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["SN COMPUT. SCI."],"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>While privacy-preserving mechanisms aim to protect sensitive information at the attribute level, distributed complex event processing (DCEP) systems remain vulnerable to privacy breaches through the detection of event patterns. Even if individual events are not inherently private, their combination into patterns can reveal sensitive knowledge. This article investigates the integration of pattern-level privacy within the APP-CEP context. We address the challenge of selectively applying obfuscation techniques to event-based systems to safeguard sensitive information. Unlike existing methods, we aim to establish event-stream-agnostic privacy by formulating queries and privacy constraints using CEP-like patterns, and constructing pattern dependency graphs to dynamically select obfuscation techniques that have no consequences on detecting other sensitive patterns, as well as non-sensitive patterns required to provide an acceptable quality of service. Additionally, we model potential adversary\u2019s knowledge that could compromise privacy and analyze its influence on the obfuscation process. We evaluated APP-CEP\u2019s performance using two real-world datasets: online retail transactions and medical records, replayed as temporally ordered event streams. Our results indicate that APP-CEP effectively balances privacy and utility. By modeling background knowledge, we also successfully prevented adversaries from detecting modifications to the input streams.<\/jats:p>","DOI":"10.1007\/s42979-025-04574-1","type":"journal-article","created":{"date-parts":[[2025,12,10]],"date-time":"2025-12-10T11:15:58Z","timestamp":1765365358000},"update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Pattern-Level Privacy Protection in Event-Based Systems"],"prefix":"10.1007","volume":"6","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-1326-7540","authenticated-orcid":false,"given":"Majid","family":"Lotfian Delouee","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Victoria","family":"Degeler","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Peter","family":"Amthor","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Martijn C.","family":"Schut","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Boris","family":"Koldehofe","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"297","published-online":{"date-parts":[[2025,12,10]]},"reference":[{"key":"4574_CR1","doi-asserted-by":"crossref","unstructured":"Lotfian\u00a0Delouee M, Koldehofe B, Degeler V, Towards adaptive quality-aware complex event processing in the internet of things. In: Proceedings of the 18th International Conference on Mobility, Sensing and Networking (MSN\u201922). IEEE; 2022. p. 571\u2013575 .","DOI":"10.1109\/MSN57253.2022.00095"},{"key":"4574_CR2","doi-asserted-by":"crossref","unstructured":"Lotfian Delouee M, Koldehofe B, Degeler V, Aqua-cep: Adaptive quality-aware complex event processing in the internet of things. In: Proceedings of the 17th ACM International Conference on Distributed and Event-Based Systems (DEBS\u201923). ACM; 2023. p. 13\u201324.","DOI":"10.1145\/3583678.3596884"},{"key":"4574_CR3","doi-asserted-by":"crossref","unstructured":"Khalil A, Lotfian\u00a0Delouee M, Degeler V, Meuser T, Anta AF, Koldehofe B, Driving towards efficiency: Adaptive resource-aware clustered federated learning in vehicular networks. In: Proceedings of the 22nd Mediterranean Communication and Computer Networking Conference (MedComNet\u201924). IEEE; 2024.","DOI":"10.1109\/MedComNet62012.2024.10578208"},{"key":"4574_CR4","doi-asserted-by":"crossref","unstructured":"Lotfian Delouee M, Koldehofe B, Degeler V, Poster: Towards pattern-level privacy protection in distributed complex event processing. In: Proceedings of the 17th ACM International Conference on Distributed and Event-Based Systems. ACM; 2023. p. 185\u2013186 .","DOI":"10.1145\/3583678.3603278"},{"key":"4574_CR5","doi-asserted-by":"crossref","unstructured":"Palanisamy SM, D\u00fcrr F, Tariq MA, Rothermel K, Preserving privacy and quality of service in complex event processing through event reordering. In: Proceedings of the 12th ACM International Conference on Distributed and Event-based Systems. 2018. p. 40\u201351.","DOI":"10.1145\/3210284.3210296"},{"key":"4574_CR6","doi-asserted-by":"crossref","unstructured":"Lotfian Delouee M, Degeler V, Amthor P, Koldehofe B, App-cep: Adaptive pattern-level privacy protection in complex event processing systems. 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