• Journal of the Korea Institute of Information Security & Cryptology
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• v.25 no.2
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• pp.271-278
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• 2015

We use various types of cryptographic algorithms for the protection of personal and sensitive informations in the application environments, such as an internet banking and an electronic commerce. However, recent researches were introduced that if we implement modes of operation, padding method and other cryptographic implementations in a wrong way, then the critical information can be leaked even though the underlying cryptographic algorithms are secure. Among these attacking techniques, the padding oracle attack is representative. In this paper, we analyze the possibility of padding oracle attacks of 12 kinds of padding techniques that can be applied to the CBC operation mode of a block cipher. As a result, we discovered that 3 kinds were safe padding techniques and 9 kinds were unsafe padding techniques. We propose 5 considerations when designing a safe padding techniques to have a resistance to the padding oracle attack through the analysis of three kinds of safe padding techniques.

• Journal of Internet Computing and Services
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• v.9 no.6
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• pp.37-48
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• 2008

VoIP service is a transmission of voice data using SIP protocol on IP based network, The SIP protocol has many advantages such as providing IP based voice communication and multimedia service with cheap communication cost and so on. Therefore the SIP protocol spread out very quickly. But, SIP protocol exposes new forms of vulnerabilities on malicious attacks such as Message Flooding attack and protocol parsing attack. And it also suffers threats from many existing vulnerabilities like on IP based protocol. In this paper, we propose a new Virtual Proxy Server system in front of the existed Proxy Server for anomaly detection of SIP attack and stateful management of SIP session with enhanced security. Based on stateful virtual proxy server, out solution shows promising SIP Message Flooding attack verification and detection performance with minimized latency on SIP packet transmission.

• Journal of Internet Computing and Services
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• v.11 no.4
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• pp.23-32
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• 2010

In this paper, we first propose the security enhancing of authentication protocol for Hash based RFID tag, and then a digital Codec for RFID tag is designed based on the proposed authentication protocol. The protocol is based on a three-way challenge response authentication protocol between the tags and a back-end server. In order to realize a secure cryptographic authentication mechanism, we modify three types of the protocol packets which defined in the ISO/IEC 18000-3 standard. Thus active attacks such as the Man-in-the-middle and Replay attacks can be easily protected. In order to verify effectiveness of the proposed protocol, a digital Codec for RFID tag is designed using Verilog HDL, and also synthesized using Synopsys Design Compiler with Hynix $0.25\;{\mu}m$ standard-cell library. Through security analysis and comparison result, we will show that the proposed scheme has better performance in user data confidentiality, tag anonymity, Man-in-the-middle attack prevention, replay attack, forgery resistance and location tracking.

• Journal of Internet Computing and Services
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• v.16 no.2
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• pp.27-40
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• 2015

Inferring firewall policy is to discover firewall policy by analyzing response packets as results of active probing without any prior information. However, a brute-force approach for generating probing packets is unavailable because the probing packets may be regarded as attack traffic and blocked by attack detection threshold of a firewall. In this paper, we propose a firewall policy inference method using an efficient probing algorithm which considers the number of source IP addresses, maximum probing packets per second and interval size of adjacent sweep lines as inference parameters to avoid detection. We then verify whether the generated probing packets are classified as network attack patterns by a firewall, and present the result of evaluation of the correctness by comparing original firewall policy with inferred firewall policy.

• Convergence Security Journal
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• v.5 no.4
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• pp.27-32
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• 2005

Recently The social interest regarding is coming to be high about Home Network accordong to intelligence anger of diffusions and the family home appliance machineries and tools of the superhigh speed Internet In the ubiquitous computing socioty, only neither the threat of the private life which is caused by in cyber attack will be able to increase according to the computer environment dependence degree of the individual increases in the ubiquitous computing socioty, only neither the threat of the private life which is caused by in cyber attack will be able to increase according to the computer environment dependence degree of the individual increases Beacaues of Home network is starting point to go ubiquitous computing enviorment, The Increase of Cyber attack through Internet will raise its head with the obstacle to disrupt the activation of the groove network. So there is a possibility of saying that the counter-measure preparation is urgent, In the various environment like this, It means the threat which present time than is complicated will exist. So it will analyze the Home network system environment of present time and observe the Security threat and attack type in the ubiquitous computing enviorment. So it will analyze the Home network system environment of present time and observe the Security threat and attack type in the ubiquitous computing enviorment.

• Journal of Internet Computing and Services
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• v.10 no.6
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• pp.229-239
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• 2009

To solve user authentication problem, many remote user authentication schemes using password and smart card at the same time have been proposed. Due to the increasing of interest in personal privacy, there were some recent researches to provide user anonymity. In 2004, Das et al. firstly proposed an authentication scheme that guarantees user anonymity using a dynamic ID. In 2005, Chien et al. pointed out that Das et al.'s scheme has a vulnerability for guaranteing user anonymity and proposed an improved scheme. However their authentication scheme was found some weaknesses about insider attack, DoS attack, and restricted replay attack. In this paper, we propose an enhanced scheme which can remove vulnerabilities of Chien et al.'s scheme. The proposed authentication protocol prevented insider attack by using user's Nonce value and removed the restricted replay attack by replacing time stamp with random number. Furthermore, we improved computational efficiency by eliminating the exponentiation operation.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.20 no.2
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• pp.145-156
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• 2010

Now a days, the development of TV and internet like communicational technique makes IPTV service which combines internet with multimedia contents increase. But when a user gets service in specific place, the certification process and user's ID check in IPTV service is complicate so that there occurs communicational difficulty like increasing illegal users and service delay etc. This paper proposes communication security mechanism to prevent Clone attack which happens in wireless section by efficiently extracting illegal user. The proposed mechanism performs key distribution procedure, inter certification procedure, and key initiation procedure by putting security agent in RFID-USB for RFID tags users use to perform plug-and-plug function. Also, the proposed mechanism updates the hased token value by its ID and the random number which RFID-USB creates whenever a user accesses in the area of RFID-USB so that it protects reply attack and man-in-the-middle attack which happen often in the area of wireless section.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.11
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• pp.3738-3760
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• 2022

Due to increasing spectrum demand for new wireless devices applications, cooperative spectrum sensing (CSS) paradigm is the most promising solution to alleviate the spectrum shortage problem. However, in the interweave cognitive radio (CR) system, the inherent nature of CSS opens a hole to Byzantine attack, thereby resulting in a significant drop of the CSS security and efficiency. In view of this, a weighted differential sequential single symbol (WD3S) algorithm based on MATLAB platform is developed to accurately identify malicious users (MUs) and benefit useful sensing information from their malicious reports in this paper. In order to achieve this, a dynamic Byzantine attack model is proposed to describe malicious behaviors for MUs in an interweave CR system. On the basis of this, a method of data transmission consistency verification is formulated to evaluate the global decision's correctness and update the trust value (TrV) of secondary users (SUs), thereby accurately identifying MUs. Then, we innovatively reuse malicious sensing information from MUs by the weight allocation scheme. In addition, considering a high spectrum usage of primary network, a sequential and differential reporting way based on a single symbol is also proposed in the process of the sensing information submission. Finally, under various Byzantine attack types, we provide in-depth simulations to demonstrate the efficiency and security of the proposed WD3S.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.3
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• pp.916-937
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• 2023

Most of the existing Distributed Denial-of-Service mitigation schemes in Software-Defined Networking are only implemented in the network domain managed by a single controller. In fact, the zombies for attackers to launch large-scale DDoS attacks are actually not in the same network domain. Therefore, abnormal traffic of DDoS attack will affect multiple paths and network domains. A single defense method is difficult to deal with large-scale DDoS attacks. The cooperative defense of multiple domains becomes an important means to effectively solve cross-domain DDoS attacks. We propose an efficient multi-domain DDoS cooperative defense mechanism by integrating blockchain and SDN architecture. It includes attack traceability, inter-domain information sharing and attack mitigation. In order to reduce the length of the marking path and shorten the traceability time, we propose an AS-level packet traceability method called ASPM. We propose an information sharing method across multiple domains based on blockchain and smart contract. It effectively solves the impact of DDoS illegal traffic on multiple domains. According to the traceability results, we designed a DDoS attack mitigation method by replacing the ACL list with the IP address black/gray list. The experimental results show that our ASPM traceability method requires less data packets, high traceability precision and low overhead. And blockchain-based inter-domain sharing scheme has low cost, high scalability and high security. Attack mitigation measures can prevent illegal data flow in a timely and efficient manner.

• International journal of advanced smart convergence
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• v.6 no.4
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• pp.56-59
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• 2017

In this paper, we design a covert channel based on instruction gadgets in smart sensing devices. Unlike the existing convert channels that usually utilize diverse physical characteristics or user behaviors or sensory data of smart sensing devices, we show that instruction gadgets could be exploited for covert channel establishment in smart sensing devices. In our devised covert channels, trojan smart sensing devices exchange attack packets in such a way that they encode an attack bit in attack packet to a series of addresses of instruction gadgets and decode an attack bit from a series of addresses of instruction gadgets.