• Electronics and Telecommunications Trends
• /
• v.33 no.1
• /
• pp.68-77
• /
• 2018

Data deduplication is a common used technology in backup systems and cloud storage to reduce storage costs and network traffic. To preserve data privacy from servers or malicious attackers, there has been a growing demand in recent years for individuals and companies to encrypt data and store encrypted data on a server. In this study, we introduce two cryptographic primitives, Convergent Encryption and Message-Locked Encryption, which enable deduplication of encrypted data between clients and a storage server. We analyze the security of these schemes in terms of dictionary and poison attacks. In addition, we introduce deduplication systems that can be implemented in real cloud storage, which is a practical application environment, and describes the proof of ownership on client-side deduplication.

• Journal of Korea Multimedia Society
• /
• v.21 no.1
• /
• pp.26-33
• /
• 2018

As financial transactions using mobile devices have been activated, mobile payment services have appeared and many changes have been made to the existing financial service methods. Due to the simplified payment method of mobile payment service, security threats such as personal information leakage, phishing damage, and malicious code are increasing. Research that can solve this is needed. In this paper, we discuss the features and security factors of mobile payment system. In order to improve the security of mobile payment system, we propose a fault analysis method based on frequency of occurrence using Fault Fishbone Analysis(FFA) technique.

• Annual Conference of KIPS
• /
• 2005.05a
• /
• pp.1461-1464
• /
• 2005

In contrast with conventional networks, mobile ad hoc networks usually do not provide online access to trusted authorities or to centralized servers, and they exhibit frequent partitioning due to link and node failures and node mobility. For these reasons, traditional security solutions that require online trusted authorities or certificate repositories, but those are not well-suited for securing ad hoc networks. Moreover, a fundamental issue of securing mobile ad hoc networks is to ensure mobile nodes can authenticate each other. Because of its strength and efficiency, public key and digital signature is an ideal mechanism to construct the authentication service. Although this is already mature in the internet application, providing public key based authentication is still very challenging in mobile ad hoc networks. In this paper I propose a secure public key authentication service based on clustering model and trust model to protect nodes from getting false public keys of the others efficiently when there are malicious nodes in the network.

• Annual Conference of KIPS
• /
• 2018.10a
• /
• pp.242-245
• /
• 2018

모바일 앱 환경에서의 광고는 앱 내부에 배너형, 팝업 형 등 다양한 형태의 광고를 띄우고, 사용자의 터치를 유도하는 등의 방법으로 광고 수익이 발생한다는 특징이 있다. 하지만, 악의적 광고주 또는 공격자는 이러한 특징을 악용해 앱 내에서의 정당한 광고를 다른 광고로 바꾸거나, 사용자에게 의도되지 않는 광고를 노출하는 등의 광고 인젝션을 발생시킨다. 광고 인젝션은 광고주에겐 수익 저하, 서비스 제공자에겐 서비스의 품질 저하, 서비스 이용자에겐 불편함을 야기하는 등 문제가 된다. 모바일 앱 환경에서의 광고 인젝션에 대한 연구 및 탐지 방법에 대한 연구는 몇몇 진행되었으나, 미진한 상황이다. 본 연구에서는 모바일 환경에서의 광고 인젝션 탐지를 위한 광고 인젝션 앱만의 특징 수집을 위해 광고 인젝션 앱, 특히 사용자가 많은 안드로이드 환경에서의 앱을 분석하는 방법을 제시한다.

• Proceedings of the Korean Information Science Society Conference
• /
• 2012.06c
• /
• pp.221-223
• /
• 2012

안드로이드 모바일 플랫폼 환경에서 정보유출, 과금유발 그리고 피싱과 같은 행위를 하는 대부분의 악성코드는 안드로이드 환경에서 기본적으로 제공되는 API(Application Programming Interface)를 이용한 것으로, 이러한 악성코드 탐지 방법으로는 정적 분석과 동적 분석 방법이 있다. 현재까지 두 가지 분석 방법에 대한 연구가 활발히 진행되고 있으며 두 가지 방식을 혼합한 형태의 검증 프로세스가 제안되고 있다. 그러나 본 논문에서 다루어지는 Radio Interface Layer 에서의 악성행위는 안드로이드 모바일 기기의 통신칩에 직접적으로 명령을 입력하는 방식으로, 그동안 악성코드 형태로 발견된 사례가 없으며, 이로 인해 발생 가능한 피해가 크므로 관련 내용을 살펴보고 대응 방안을 제시하고자 한다.

• Journal of Korea Multimedia Society
• /
• v.21 no.12
• /
• pp.1448-1458
• /
• 2018

Vehicular Ad-Hoc Networks (VANETs) have become one of the active areas of research, standardization, and development because they have tremendous potentials to improve vehicle and road safety, traffic efficiency, and convenience as well as comfort to both drivers and passengers. However, message trustfulness is a challenge because the propagation of false message by malicious vehicles induces unreliable and ineffectiveness of VANETs, Therefore, we need a reliable reputation method to ensure message trustfulness. In this paper, we consider a vulnerability against the Sybil attack of the previous reputation systems based on blockchain and suggest a new reputation system which resists against Sybil attack on the previous system. We propose an initial authentication process as a countermeasure against a Sybil attack and provide a reliable reputation with a cooperative message delivery to cope with message omission. In addition, we use Homomorphic Commitment to protect the privacy breaches in VANETs environment.

• IEMEK Journal of Embedded Systems and Applications
• /
• v.14 no.5
• /
• pp.239-247
• /
• 2019

Recently, successful attacks on cyber-physical systems have been reported. As existing network security solutions are limited in preventing the system from malicious attacks, appropriate countermeasures are required from the perspective of the control. In this paper, the cyber and physical attacks are interpreted in terms of actuator and sensor attacks. Based on the interpretation, we suggest a strategy for designing Kalman filters to secure the resilience and safety of the system. Such a strategy is implemented in details to be applied for the lateral control of autonomous driving vehicle. A set of simulation results verify the performance of the proposed Kalman filters.

• Annual Conference of KIPS
• /
• 2013.11a
• /
• pp.871-874
• /
• 2013

기존 PC에서 발생되는 악성코드가 안드로이드 모바일 플랫폼에서 스미싱 어플리케이션으로 급증하고 있다. 스마트 폰 사용자는 SMS에 의해 악성코드를 설치하게 되며, 악성코드가 소액결제 서비스 인증번호를 가로채어 C&C 서버 등으로 송신함으로써 30 만원 이내의 금전적 손해를 일으키게 된다. 본 논문에서는 GCM(Google Cloud Messaging)과 MDM(Mobile Device Management)을 이용하여 사용자의 스마트 폰에서 동작하고 있는 악성 어플리케이션을 탐지하고, 악성 행위를 통제시키며 사용자로부터 직접 어플리케이션을 삭제하길 권하는 시스템을 설계하여 제안하고자 한다.

• Annual Conference of KIPS
• /
• 2020.05a
• /
• pp.231-234
• /
• 2020

In the past few years, the industrial internet of things (IIoT) has received great attention in various industrial sectors which have potentially increased a high level of integrity, availability, and scalability. The increasing of IIoT is expected to create new smart industrial enterprises and build the next generation smart system. However existing IIoT systems rely on centralized servers that are vulnerable to a single point of failure and malicious attack, which exposes the data to security risks and storage. To address the above issues, blockchain is widely considered as a promising solution, which can build a secure and efficient environment for data storing, processing and sharing in IIoT. In this paper, we propose a decentralized, peer-to-peer platform for secure data storing in industrial IoT base on the ethereum blockchain. We exploit ethereum to ensure data security and reliability when smart devices store the data.

• Nuclear Engineering and Technology
• /
• v.56 no.3
• /
• pp.1108-1115
• /
• 2024

Assuring physical security for Micro Modular Reactors (MMRs) will be key to their licensing. Economic constraints however require changes in how the security objectives are achieved for MMRs. A promising new approach is the so-called performance based (PB) approach wherein the regulator formally sets general security objectives and leaves it to the licensee to set their own specific acceptance criteria to meet those objectives. To implement the PB approach for MMRs, one performs a consequence-based analysis (CBA) whose objective is to study hypothetical malicious attacks on the facility, assuming that intruders take control of the facility and perform any technically possible action within a limited time before an offsite security force can respond. The scenario leading to the most severe radiological consequences is selected and studied to estimate the limiting impact on public health. The CBA estimates the total amount of radionuclides that would be released to the atmosphere in this hypothetical scenario to determine the total radiation dose to which the public would be exposed. The predicted radiation exposure dose is then compared to the regulatory dose limit for the site. This paper describes application of the CBA to four different MMRs technologies.