Rapid developments in mobile technology have transformed mobile phones into personal multimedia devices. Due to these advancements, user created mobile content is on the increase, both in terms of quality and quantity. In addition, content sharing is getting popular in home networks as well as in social community networks. To keep pace with such movements, the new networking technology named as content centric networking (CCN) optimized for content sharing has appeared. However, it has little consideration for mobile consumer devices. So, this paper indicates that the proxy-based CCN scheme can provide lower communication overhead, shorter download time, and lower energy consumption in mobile environments.

Ransomware, which is one type of malware, encrypts a user's files on a device and then requires the user to pay a ransom to recover the damaged files. The amount of ransomware is growing so rapidly that it constituted more than 70% of the malware found in 2017. Although many ransomware solutions have been released, similar to traditional antimalware solutions, most ransomware solutions are designed based on a blacklist that includes the code signatures of known ransomware. However, such blacklist-based solutions cannot prevent unknown ransomware, which may be either new or a variation of an existing ransomware. Another solution is to continuously monitor the abnormal behavior of every software program running on a user's device. To do so, some solutions monitor the executing programs that access the files stored on a device, while other solutions specify a folder as a safe folder and control executing programs when they access the objects in the folder. However, these solutions can degrade the performances of devices or inconvenience users. This article presents a new solution to detect/prevent ransomware using a whitelist. We analyze the file operation procedures of a user-device operating system and then implement a whitelist-based access control as a partial file operation procedure. Since the solution utilizes a whitelist and not a blacklist, it does not need to patch in the information on new ransomware regularly provided by a ransomware solution provider. Therefore, it can prevent both unknown and future ransomware in real time.

The increase of user generated mobile content raises the need of mobile content sharing. Moreover, content centric networking (CCN) is known for the new efficient network architecture appropriate for con tent sharing. However, it has little consideration for mobile devices. So, this paper indicates that the proxy-based CCN scheme can provide lower communication overhead and shorter download time in mobile environments.

Recently, new mobile applications and services have appeared thanks to the rapid development of mobile devices and mobile network technology. Cloud computing has played an important role over the past decades, providing powerful computing capabilities and high-capacity storage space to efficiently deliver these mobile services to mobile users. Nevertheless, existing cloud computing delegates computing to a cloud server located at a relatively long distance, resulting in significant delays due to additional time to return processing results from a cloud server. These unnecessary delays are inconvenient for mobile users because they are not suitable for applications that require a real-time service environment. To cope with these problems, a new computing concept called Multi-Access Edge Computing (MEC) has emerged. Instead of sending all requests to the central cloud to handle mobile users’ requests, the MEC brings computing power and storage resources to the edge of the mobile network. It enables the mobile user device to run the real-time applications that are sensitive to latency to meet the strict requirements. However, there is a lack of research on the efficient utilization of computing resources and mobility support when mobile users move in the MEC environment. In this paper, we propose the MEC-based mobility management scheme that arranges MEC server (MECS) as the concept of Zone so that mobile users can continue to receive content and use server resources efficiently even when they move. The results show that the proposed scheme reduce the average service delay compared to the existing MEC scheme. In addition, the proposed scheme outperforms the existing MEC scheme because mobile users can continuously receive services, even when they move frequently.

As the majority of Internet traffic is becoming a variety of high quality multimedia and is mostly generated by consumers, efficient and usable content sharing in home as well as in mobile environment remains an elusive goal. For intuitive content sharing experience, an attractive approach named a content-centric networking (CCN) based virtual private community service has been proposed. The proposed CCN-based private community service had a hierarchical domain structure to efficiently manage multiple user and home domains. But it wasn't described how users can construct the hierarchical domain. In this paper, we propose the procedure of how users intuitively and securely construct CCN-based virtual private community. To support the construction of the proposed CCN-based virtual private community, this paper proposes two main points: one is a membership association to represent the relationship between the members of a domain as well as between hierarchical domains. The other is location-limited channel (LLC)-based enrollment schemes to identify devices adaptively available for both short and long distance as well as to issue a membership credential to newcomer-devices. From the proposal, users can easily and securely identify community member's devices without using a trust third party (TTP) and can configure the memberships of all community domain classes for a newcomer-device only by one registration operation. Hence, the users can securely and easily construct their private communities to share private contents among the members of the communities.

As smart home systems increasingly utilize AI technology, a user-friendly and intelligent smart home system becomes increasingly popular. However, a home generally consists of various devices with different capabilities from different vendors. Hence, it is difficult to apply high-performance security solutions to such a smart home system. Recently, although a blockchain is mentioned as an alternative, it needs a high computation resource because of the mining process of PoW. So, to apply a blockchain to a smart home system, it is necessary to address such a high resource problem. This paper proposes a reverse hash chain as an alternative PoW for a blockchain-based smart home authentication. Since this proposed scheme needs small numbers of hash value computations for PoW, a user can apply a blockchain to a smart home.