{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,21]],"date-time":"2026-03-21T22:14:17Z","timestamp":1774131257936,"version":"3.50.1"},"reference-count":36,"publisher":"Privacy Enhancing Technologies Symposium Advisory Board","issue":"4","license":[{"start":{"date-parts":[[2017,10,1]],"date-time":"2017-10-01T00:00:00Z","timestamp":1506816000000},"content-version":"unspecified","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc-nd\/3.0"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2017,10,1]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:p>This paper studies the possibility of using the encrypted video channel of widely used videoconferencing applications, such as Skype, as a carrier for unobservable covert TCP\/IP communications. We propose and evaluate different alternatives to encode information in the video stream in order to increase available throughput while preserving the packet-level characteristics of the video stream. We have built a censorship-resistant system, named DeltaShaper, which offers a data-link interface and supports TCP\/IP applications that tolerate low throughput \/ high latency links. Our results show that it is possible to run standard protocols such as FTP, SMTP, or HTTP over Skype video streams.<\/jats:p>","DOI":"10.1515\/popets-2017-0037","type":"journal-article","created":{"date-parts":[[2017,10,17]],"date-time":"2017-10-17T10:01:46Z","timestamp":1508234506000},"page":"5-22","source":"Crossref","is-referenced-by-count":27,"title":["DeltaShaper: Enabling Unobservable Censorship-resistant TCP Tunneling over Videoconferencing Streams"],"prefix":"10.56553","volume":"2017","author":[{"given":"Diogo","family":"Barradas","sequence":"first","affiliation":[{"name":"INESC-ID, Instituto Superior T\u00e9cnico , Universidade de Lisboa"}]},{"given":"Nuno","family":"Santos","sequence":"additional","affiliation":[{"name":"INESC-ID, Instituto Superior T\u00e9cnico , Universidade de Lisboa"}]},{"given":"Lu\u00eds","family":"Rodrigues","sequence":"additional","affiliation":[{"name":"INESC-ID, Instituto Superior T\u00e9cnico , Universidade de Lisboa"}]}],"member":"35752","published-online":{"date-parts":[[2017,10,10]]},"reference":[{"key":"2021040704543029504_j_popets-2017-0037_ref_001_w2aab3b7b2b1b6b1ab1ab1Aa","doi-asserted-by":"crossref","unstructured":"[1] C. 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