Covert communication is designed for hiding the subliminal which takes place between both of speakers and their relationship. The traditional covert utilizes centralized channel third-party central node or authority to distribute messages leads a lack undetectability, antitraceability, robustness. In recent years, there have been attempts apply blockchain solutions, characteristics such as dece...

A network covert channel is a mechanism that can be used to leak information across a network in violation of a security policy and in a manner that can be difficult to detect. Detecting and preventing covert channels is particularly important for multilevel security systems in which processes working with classified information may leak information to processes with a lower classification leve...

Covert channels are not new in computing systems, and have been studied since their first definition four decades ago. New platforms invoke thorough investigations to assess their security. Now is the time for Android platform to analyze its security model, in particular the two key principles: process-isolation and the permissions system. Aside from all sorts of malware, one threat proved intr...

Covert channels aim to hide the existence of communication. Recently proposed packet-timing channels encode covert data in inter-packet times, based on models of inter-packet times of normal traffic. These channels are detectable if normal inter-packet times are not independent identically-distributed, which we demonstrate is the case for several network applications. We show that ~80% of chann...

Communication from a low-to a high-level system without acknowledgements will be unreliable; with acknowledgements, it can be insecure. We propose to provide quantiiable security, acceptable reliability, and minimal performance penalties by interposing a device (called the Pump) to push messages to the high system and provide a controlled stream of acknowledgements to the low system. This paper...

Covert communication can prevent the adversary from knowing that a wireless transmission has occurred. In the additive white Gaussian noise channels, a square root law is obtained and the result shows that Alice can reliably and covertly transmit O(√n) bits to Bob in n channel uses. If additional “friendly” node near the adversary can inject artificial noise to aid Alice in hiding her transmiss...

In this paper, we show that attackers can leak data from isolated, air-gapped computers to nearby smartphones via covert magnetic signals. The proposed covert channel works even if a smartphone is kept inside a Faraday shielding case, which aims to block any type of inbound and outbound wireless communication (Wi-Fi, cellular, Bluetooth, etc.). The channel also works if the smartphone is set in...

Despite extensive research, covert channels are a principal threat to information security. Covert channels employ specially-crafted content or timing characteristics to transmit internal information to external attackers. Most techniques for detecting covert channels model legitimate network traffic. However, such an approach may not be applicable in dynamic virtualized environments because tr...