{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,7,13]],"date-time":"2025-07-13T16:40:03Z","timestamp":1752424803868,"version":"3.41.2"},"reference-count":0,"publisher":"Privacy Enhancing Technologies Symposium Advisory Board","issue":"4","license":[{"start":{"date-parts":[[2025,10,1]],"date-time":"2025-10-01T00:00:00Z","timestamp":1759276800000},"content-version":"unspecified","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["PoPETs"],"abstract":"<jats:p>Smartwatches such as the Apple Watch collect vast amounts of intimate health and fitness data as we wear them. Users have little choice regarding how this data is processed: The Apple Watch can only be used with Apple's iPhones, using their software and their cloud services. We are the first to publicly reverse-engineer the watch's wireless protocols, which led to discovering multiple security issues in Apple's proprietary implementation. With WatchWitch, our custom Android reimplementation, we break out of Apple's walled garden-demonstrating practical interoperability with enhanced privacy controls and data autonomy. We thus pave the way for more consumer choice in the smartwatch ecosystem, offering users more control over their devices.<\/jats:p>","DOI":"10.56553\/popets-2025-0121","type":"journal-article","created":{"date-parts":[[2025,7,13]],"date-time":"2025-07-13T15:58:27Z","timestamp":1752422307000},"page":"94-111","source":"Crossref","is-referenced-by-count":0,"title":["WatchWitch: Interoperability, Privacy, and Autonomy for the Apple Watch"],"prefix":"10.56553","volume":"2025","author":[{"given":"Nils","family":"Rollshausen","sequence":"first","affiliation":[{"name":"Secure Mobile Networking Lab, Technical University of Darmstadt"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Alexander","family":"Heinrich","sequence":"additional","affiliation":[{"name":"Secure Mobile Networking Lab, Technical University of Darmstadt"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Matthias","family":"Hollick","sequence":"additional","affiliation":[{"name":"Secure Mobile Networking Lab, Technical University of Darmstadt"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jiska","family":"Classen","sequence":"additional","affiliation":[{"name":"Hasso Plattner Institute, University of Potsdam"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"35752","published-online":{"date-parts":[[2025,10]]},"container-title":["Proceedings on Privacy Enhancing Technologies"],"original-title":[],"deposited":{"date-parts":[[2025,7,13]],"date-time":"2025-07-13T15:58:29Z","timestamp":1752422309000},"score":1,"resource":{"primary":{"URL":"https:\/\/petsymposium.org\/popets\/2025\/popets-2025-0121.php"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,10]]},"references-count":0,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2025,10]]}},"alternative-id":["10.56553\/popets-2025-0121"],"URL":"https:\/\/doi.org\/10.56553\/popets-2025-0121","relation":{},"ISSN":["2299-0984"],"issn-type":[{"type":"electronic","value":"2299-0984"}],"subject":[],"published":{"date-parts":[[2025,10]]}}}