González Manzano, LorenaBernárdez, SergioFuentes García-Romero de Tejada, José María de2022-01-192022-01-192020-12-29L. Gonzalez-Manzano, S. Bernardez and J. M. de Fuentes, "SmartLED: Smartphone-Based Covert Channels Leveraging the Notification LED," 2020 IEEE 19th International Conference on Trust, Security and Privacy in Computing and Communications (TrustCom), 2020, pp. 1748-1755, doi: 10.1109/TrustCom50675.2020.00240.978-1-6654-0392-4https://hdl.handle.net/10016/33916The widespread adoption of smartphones make them essential in daily routines. Thus, they can be used to create a covert channel without raising suspicions. To avoid detection, networkless communications are preferred. In this paper, we propose SmartLED, a mechanism to build covert channels leveraging a widely available smartphone feature - its notification LED. The secret is encoded through LED blinks using Manhattan encoding. SmartLED is assessed in real-world indoor and outdoor scenarios, considering different distances up to 5 meters. Our results show that the best performance is achieved in dark settings - 34.8 s. are needed to exfiltrate a 7-byte password to a distance of 1 m. Remarkably, distance does not cause a great impact on effective transmission time and shorter blinks do not lead to substantially greater transmission errorseng©2020 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale orredistribution to servers or lists, or reuse of any copyrighted component of this work in other works.smartphonecovert communicationcovert channelnotification ledconference proceedingsInformáticahttps://doi.org/10.1109/TrustCom50675.2020.00240open access17481755Proceedings of 2020 IEEE 19th International Conference on Trust, Security and Privacy in Computing and Communications (TrustCom)CC/0000031106