Biblio
Bitcoin, a peer-to-peer payment system and digital currency, is often involved in illicit activities such as scamming, ransomware attacks, illegal goods trading, and thievery. At the time of writing, the Bitcoin ecosystem has not yet been mapped and as such there is no estimate of the share of illicit activities. This paper provides the first estimation of the portion of cyber-criminal entities in the Bitcoin ecosystem. Our dataset consists of 854 observations categorised into 12 classes (out of which 5 are cybercrime-related) and a total of 100,000 uncategorised observations. The dataset was obtained from the data provider who applied three types of clustering of Bitcoin transactions to categorise entities: co-spend, intelligence-based, and behaviour-based. Thirteen supervised learning classifiers were then tested, of which four prevailed with a cross-validation accuracy of 77.38%, 76.47%, 78.46%, 80.76% respectively. From the top four classifiers, Bagging and Gradient Boosting classifiers were selected based on their weighted average and per class precision on the cybercrime-related categories. Both models were used to classify 100,000 uncategorised entities, showing that the share of cybercrime-related is 29.81% according to Bagging, and 10.95% according to Gradient Boosting with number of entities as the metric. With regard to the number of addresses and current coins held by this type of entities, the results are: 5.79% and 10.02% according to Bagging; and 3.16% and 1.45% according to Gradient Boosting.
Smart home automation and IoT promise to bring many advantages but they also expose their users to certain security and privacy vulnerabilities. For example, leaking the information about the absence of a person from home or the medicine somebody is taking may have serious security and privacy consequences for home users and potential legal implications for providers of home automation and IoT platforms. We envision that a new ecosystem within an existing smartphone ecosystem will be a suitable platform for distribution of apps for smart home and IoT devices. Android is increasingly becoming a popular platform for smart home and IoT devices and applications. Built-in security mechanisms in ecosystems such as Android have limitations that can be exploited by malicious apps to leak users' sensitive data to unintended recipients. For instance, Android enforces that an app requires the Internet permission in order to access a web server but it does not control which servers the app talks to or what data it shares with other apps. Therefore, sub-ecosystems that enforce additional fine-grained custom policies on top of existing policies of the smartphone ecosystems are necessary for smart home or IoT platforms. To this end, we have built a tool that enforces additional policies on inter-app interactions and permissions of Android apps. We have done preliminary testing of our tool on three proprietary apps developed by a future provider of a home automation platform. Our initial evaluation demonstrates that it is possible to develop mechanisms that allow definition and enforcement of custom security policies appropriate for ecosystems of the like smart home automation and IoT.
The QR codes have gained wide popularity in mobile marketing and advertising campaigns. However, the hidden security threat on the involved information system might endanger QR codes' success, and this issue has not been adequately addressed. In this paper we propose to examine the life cycle of a redesigned QR code ecosystem to identify the possible security risks. On top of this examination, we further propose standard changes to enhance security through a digital signature mechanism.