1. Practical data hiding in TCP/IP;Ahsan,2002
2. Covert channels based on jitter field of the RTCP header;Bai,2008
3. Estimation of ‘quality per call‘ in modelled telephone conversations;Berger,2008
4. Detailed analysis of Skype traffic;Bonfiglio;IEEE Trans Multimed,2009
5. Out-of-band covert channels—a survey;Carrara;ACM Comput Surv,2016