• Journal of the Korea Institute of Information Security & Cryptology
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• v.24 no.1
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• pp.155-163
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• 2014

To enhance network efficiency, content-centric networking (CCN) proposes that intermediated network nodes on a content-delivery path temporally cache transmitted contents. Then if an intermediated node receives a content request message (Interest) for previously cached content, the node directly transmits the cached content as a response message (Data) to requestors and finishes the transmission of the received Interest. Since Interest is performed by intermediated network nodes, it is possible to efficiently transmit contents and to effectively solve a network congestion problem caused around contents sources. For that, CCN utilizes both content store to temporarily cache content and pending Interest table (PIT) to record Interest incoming Face. However, it has mentioned the possibility of denial service attack using both the limitation of PIT resource and fake Interests. In this paper, we briefly describe the presented PIT flooding attack utilizing fake Interest. Then we introduce new attack possibility using fake Data and propose a countermeasure for the proposed attack. Also we evaluate the performance of our proposal.

• Journal of Convergence Society for SMB
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• v.4 no.3
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• pp.1-6
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• 2014

DDoS (Distributed Denial Service, Distributed Service) attacks are being generated for a constant threat on the Internet, countermeasures for this have been proposed. However, the problem has become an increasingly effective instruction in any Measures are a variety of attacks and sophisticated attacks. Attackers can change a steady attack tools to respond to these, the experts as a countermeasure to this constantly research for a fresh attack. This paper is to introduce countermeasures to DDoS recent representative examples of 7.7DDoS and look for 3.3DDoS existing types of DDoS attacks increased PPS attacks, high traffic sent, web service delay and router and firewall settings, applications and to describe the DDoS countermeasures research by certification, is so that you can plan effectively for the future DDoS attacks proposed method.

• KIPS Transactions on Computer and Communication Systems
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• v.7 no.1
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• pp.19-26
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• 2018

Recently, DDoS amplification attacks using servers that provide Microsoft Active Directory information using CLDAP protocol are increasing. Because CLDAP is an open standard application that allows a wide range of directory information to be accessed and maintained in a network, the server is characterized by its openness to the Internet. This can be exploited by the Reflector server to perform an amplification attack by an attacker. In addition, this attack can be attacked with a packet that is amplified 70 times more than the conventional UDP-based flooding attack, and it can block service to small and medium sized server. Therefore, in this paper, we propose an algorithm that can reduce the DDoS amplification attack using CLDAP server and implement the corresponding CLDAP server environment virtually, and implement and demonstrate the corresponding algorithm. This provides a way to ensure the availability of the server.

• KIISE Transactions on Computing Practices
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• v.21 no.10
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• pp.670-679
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• 2015

With a rapid development of internet, many users these days refer to various recommender sites when buying items, movies, music and more. However, there are malicious users (Sybil) who raise or lower item ratings intentionally in these recommender sites. And as a result, a recommender system (RS) may recommend incomplete or inaccurate results to normal users. We suggest a recommender algorithm to separate ratings generated by users into normal ratings and outlier ratings, and to minimize the effects of malicious users. Specifically, our algorithm first ensures a stable RS against three kinds of attack models (Random attack, Average attack, and Bandwagon attack) which are the main recent security issues in RS. To prove the performance of the method of suggestion, we conducted performance analysis on real world data that we crawled. The performance analysis demonstrated that the suggested method performs well regardless of Sybil size and type when compared to existing algorithms.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.22 no.5
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• pp.1169-1178
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• 2012

Recently, since the most software intensive systems are using internet environment for data exchange, the software security is being treated as a big issue. And, to minimize vulnerability of software system, security ensuring steps which are applying secure coding rules, are introduced in the software development process. But, since actual attacks are using a variety of software vulnerabilities, it is hard to analyze software weakness by monotonic analysis. In this paper, it is tried to against the complex attack on the variety of software vulnerability using the coupling which is one of the important characteristic of software. Furthermore, pre-analysis of the complex attack patterns using a combination of various attack methods, is carried out to predict possible attack patterns in the relationship between software modules. And the complex attack pattern analysis method is proposed based on this result.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.5
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• pp.36-46
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• 2019

The number of hosts connected to the Internet has increased dramatically, introducing the Domain Name System(DNS) in 1984. DNS is now an important key point for all users of the Internet by allowing them to use a convenient character address without memorizing a series of numbers of complex IP address. However, relative to the importance of DNS, there still exist many problems such as the authorization allocation issue, the disputes over public registration, security vulnerability such as DNS cache poisoning, DNS spoofing, man-in-the-middle attack, DNS amplification attack, and the need for many domain names in the age of hyper-connected networks. In this paper, to effectively improve these problems of existing DNS, we proposed a method of implementing DNS using distributed ledger technology, blockchain, and implemented using a Ethereum-based platform. In addition, the qualitative analysis performance comparative evaluation of the existing domain name registration and domain name server was conducted, and conducted security assessments on the proposed system to improve security problem of existing DNS. In conclusion, it was shown that DNS services could be provided high security and high efficiently using blockchain.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.1
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• pp.119-131
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• 2013

With the explosive growth of computer networks, many remote service providing servers and multi-server network architecture are provided and it is extremely inconvenient for users to remember numerous different identities and passwords. Therefore, it is important to provide a mechanism for a remote user to use single identity and password to access multi-server network architecture without repetitive registration and various multi-server authentication schemes have been proposed in recent years. Recently, Tsaur et al. proposed an efficient and secure smart card based user authentication and key agreement scheme for multi-server environments. They claimed that their scheme satisfies all of the requirements needed for achieving secure password authentication in multi-server environments and gives the formal proof on the execution of the proposed authenticated key agreement scheme. However, we find that Tsaur et al.'s scheme is still vulnerable to impersonation attack and many logged-in users' attack. We propose an extended scheme that not only removes the aforementioned weaknesses on their scheme but also achieves user anonymity for hiding login user's real identity. Compared with other previous related schemes, our proposed scheme keeps the efficiency and security and is more suitable for the practical applications.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.4
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• pp.43-53
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• 2015

Password-based authentication schemes for server-client system are convenient to use, but vulnerable to dictionary attack or brute-force attack. To solve this vulnerability, Cryptographic secret key is used for security, but difficult to memorize. So, for the first time, Das proposed a biometric-based authentication scheme to solve various problems but it has various vulnerabilities. Afterwards, Jiping et al. improved Das's scheme, but some vulnerabilities remain. In this paper, we analyze the cryptanalysis of Jiping et al.'s authentication scheme and then propose improved biometric based user authentication scheme to resolve the analyzed problem. Moreover, we conduct a security analysis for the proposed scheme and make a comparison between the proposed scheme and other biometric based user authentications.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.5
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• pp.1343-1356
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• 2013

Cloud computing has emerged as perhaps the hottest development in information technology at present. This new computing technology requires that the users ensure that their infrastructure is safety and that their data and applications are protected. In addition, the customer must ensure that the provider has taken the proper security measures to protect their information. In order to achieve fine-grained and flexible access control for cloud computing, a new construction of hierarchical attribute-based encryption(HABE) with Ciphertext-Policy is proposed in this paper. The proposed scheme inherits flexibility and delegation of hierarchical identity-based cryptography, and achieves scalability due to the hierarchical structure. The new scheme has constant size ciphertexts since it consists of two group elements. In addition, the security of the new construction is achieved in the standard model which avoids the potential defects in the existing works. Under the decision bilinear Diffie-Hellman exponent assumption, the proposed scheme is provable security against Chosen-plaintext Attack(CPA). Furthermore, we also show the proposed scheme can be transferred to a CCA(Chosen-ciphertext Attack) secure scheme.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.10
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• pp.5023-5038
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• 2017

Big data is an emerging technology which deals with wide range of data sets with sizes beyond the ability to work with software tools which is commonly used for processing of data. When we consider a huge network, we have to process a large amount of network information generated, which consists of both normal and abnormal activity logs in large volume of multi-dimensional data. Intrusion Detection System (IDS) is required to monitor the network and to detect the malicious nodes and activities in the network. Massive amount of data makes it difficult to detect threats and attacks. Sequential Pattern mining may be used to identify the patterns of malicious activities which have been an emerging popular trend due to the consideration of quantities, profits and time orders of item. Here we propose a sequential pattern mining algorithm with fuzzy logic feature selection and fuzzy weighted support for huge volumes of network logs to be implemented in Apache Hadoop YARN, which solves the problem of speed and time constraints. Fuzzy logic feature selection selects important features from the feature set. Fuzzy weighted supports provide weights to the inputs and avoid multiple scans. In our simulation we use the attack log from NS-2 MANET environment and compare the proposed algorithm with the state-of-the-art sequential Pattern Mining algorithm, SPADE and Support Vector Machine with Hadoop environment.