• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.29 no.3C
• /
• pp.398-407
• /
• 2004

In this paper, a blind watermarking method which is suitable to the video compression using 2-D discrete wavelet transform was proposed and implemented into the hardware using VHDL(VHSIC Hardware Description Language). The goal of the proposed watermarking algorithm is the authentication about the manipulation of the watermark embedded image and the detection of the error positions. Considering the compressed video image, the proposed watermarking scheme is unrelated to the quantization and is able to concurrently embed or extract the watermark. We experimentally verified that the lowest frequency subband(LL4) is not sensitive to the change in the spatial domain, so LL4 subband was selected for the mark space. And the combination of the bitplanes which has the properties of both the minimum degradation of the image and the robustness was chosen as the embedded Point in the mark space in LL4 subband. Since we know the watermark embedded positions and the watermark is embedded by not varying the value but changing the value, the watermark can be extracted without the original image. Also, for the security when exposing the watermark embedded position, we embed the encrypted watermark by the block cipher. The proposed watermark algorithm shows the robustness against the general image manipulation and is easily transplanted into the image or video compressor with the minimal changing in the structure. The designed hardware has 4037 LABs(24％) and 85 ESBs(3％) in APEX20KC EP20K400CF672C7 FPGA of Altera and stably operates in 82MHz clock frequency.

• The Journal of Society for e-Business Studies
• /
• v.22 no.2
• /
• pp.169-185
• /
• 2017

Juliano Rizzo and Thai Duong, the authors of the BEAST attack [11, 12] on SSL, have proposed a new attack named CRIME [13] which is Compression Ratio Info-leak Made Easy. The CRIME exploits how data compression and encryption interact to discover secret information about the underlying encrypted data. Repeating this method allows an attacker to eventually decrypt the data and recover HTTP session cookies. This security weakness targets in SPDY and SSL/TLS compression. The attack becomes effective because the attacker is enable to choose different input data and observe the length of the encrypted data that comes out. Since Transport Layer Security (TLS) ensures integrity of data transmitted between two parties (server and client) and provides strong authentication for both parties, in the last few years, it has a wide range of attacks on SSL/TLS which have exploited various features in the TLS mechanism. In this paper, we will discuss about the CRIME and other versions of SSL/TLS attacks along with countermeasures, implementations. We also present direction for SSL/TLS attacks resistance in practice.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.43 no.7 s.349
• /
• pp.1-13
• /
• 2006

In this paper, we introduce a novel key management scheme that is based on the key pre-distribution but provides the key re-distribution method, in order to manage keys for message encryption and authentication of lower-layer sensor nodes on hierarchical mobile sensor networks. The characteristics of our key management are as follows: First, the role of key management is distributed to aggregator nodes as well as a sink node, to overcome the weakness of centralized management. Second, a sink node generates keys using regression model, thus it stores only the information for calculating the keys using the key information received from nodes, but does not store the relationship between a node and a key, and the keys themselves. As the disadvantage of existing key pre-distributions, they do not support the key re-distribution after the deployment of nodes, and it is hard to extend the key information in the case that sensor nodes in the network enlarge. Thirdly, our mechanism provides the resilience to node capture(${\lambda}$-security), also provided by the existing key pre-distributions, and fourth offers the key freshness through key re-distribution, key distribution to mobile nodes, and scalability to make up for the weak points in the existing key pre-distributions. Fifth, our mechanism does not fix the relationship between a node and a key, thus supports the anonymity and untraceability of mobile nodes. Lastly, we compare ours with existing mechanisms, and verify our performance through the overhead analysis of communication, computation, and memory.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.27 no.10C
• /
• pp.1015-1026
• /
• 2002

As per increasing research interest in the field of collaborative computing in recent year, the importance of security issues on that area is also incrementally growing. Generally, the persistency of collaborative system is facilitated with conventional authentication and cryptography schemes. It is however, hard to meet the access control requirements of distributed collaborative computing environments by means of merely apply the existing access control mechanisms. The distributed collaborative system must consider the network openness, and various type of subjects and objects while, the existing access control schemes consider only some of the access control elements such as identity, rule, and role. However, this may cause the state of security level alteration phenomenon. In order to handle proper access control in collaborative system, various types of access control elements such as identity, role, group, degree of security, degree of integrity, and permission should be taken into account. Futhermore, if we simply define all the necessary access control elements to implement access control algorithm, then collaborative system consequently should consider too many available objects which in consequence, may lead drastic degradation of system performance. In order to improve the state problems, we propose a novel access control framework that is suitable for the distributed collaborative computing environments. The proposed scheme defines several different types of object elements for the accessed objects and subjects, and use them to implement access control which allows us to guarantee more solid access control. Futhermore, the objects are distinguished by three categories based on the characteristics of the object elements, and the proposed algorithm is implemented by the classified objects which lead to improve the systems' performance. Also, the proposed method can support scalability compared to the conventional one. Our simulation study shows that the performance results are almost similar to the two cases; one for the collaborative system has the proposed access control scheme, and the other for it has not.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.29 no.6
• /
• pp.1243-1257
• /
• 2019

With the emergence of the IoT environment, various smart devices provide consumers with the convenience and various services. However, as security threats such as invasion of privacy have been reported, the importance of security issues in the IoT environment has emerged, and in particular, the security problem of key management has been discussed, and the PUF has been discussed as a countermeasure. In relation to the key management problem, a protocol using MIPUF has been proposed for the security problem of the group key management system. The system can be applied to lightweight IoT environments and the safety of the PUF ensures the safety of the entire system. However, in some processes, it shows vulnerabilities in terms of safety and efficiency of operation. This paper improves the existing protocol by adding authentication for members, ensuring data independence, reducing unnecessary operations, and increasing the efficiency of database searches. Safety analysis is performed for a specific attack and efficiency analysis results are presented by comparing the computational quantities. Through this, this paper shows that the reliability of data can be improved and our proposed method is lighter than existing protocol.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.12 no.12
• /
• pp.2293-2300
• /
• 2008

In ad-hoc sensor network, AODV routing information is disclosed to other nodes because AODV protocol doesn't have any security mechanisms. The problem of AODV is that an attacker can falsify the routing information in RREQ packet. If an attacker broadcasts the falsified packet, other nodes will update routing table based on the falsified one so that the path passing through the attacker itself can be considered as a shortest path. In this paper, we design the routing-information-spoofing attack such as falsifying source sequence number and hop count fields in RREQ packet. And we suggest an efficient scheme for detecting the attackers and isolating those nodes from the network without extra security modules. The proposed scheme doesn't employ cryptographic algorithm and authentication to reduce network overhead. We used NS-2 simulation to evaluate the network performance. And we analyzed the simulation results on three cases such as an existing normal AODV, AODV under the attack and proposed AODV. Simulation results using NS2 show that the AODV using proposed scheme can protect the routing-information-spoofing attack and the total n umber of received packets for destination node is almost same as the existing norm at AODV.

• Journal of IKEEE
• /
• v.23 no.2
• /
• pp.438-447
• /
• 2019

As the IoT-based hyper-connected society grows, public-key cryptosystem such as RSA is frequently used for encryption, authentication, and digital signature. Public-key cryptosystem use very large (safe) prime numbers to ensure security against malicious attacks. Even though the performance of the device has greatly improved, the generation of a large (safe)prime is time-consuming or memory-intensive. In this paper, we propose ET-MR and ET-MR-MR using Euler sieve so it runs faster while using less memory. We present a running time prediction model by probabilistic analysis and compare time and memory of our method with conventional methods. Experimental results show that the difference between the expected running time and the measured running time is less than 4%. In addition, the fastest running time of ET-MR is 36% faster than that of TD-MR, 8.5% faster than that of DT-MR and the fastest running time of ET-MR-MR is 65.3% faster than that of TD-MR-MR and similar to that of DT-MR-MR. When k=12,381, the memory usage of ET-MR is 2.7 times more than that of DT-MR but 98.5% less than that of TD-MR and when k=65,536, the memory usage of ET-MR-MR is 98.48% less than that of TD-MR-MR and 92.8% less than that of DT-MR-MR.

• The Korea Journal of Herbology
• /
• v.36 no.1
• /
• pp.9-17
• /
• 2021

Objectives : Tetrapanacis Medulla and Akebiae Caulis are one of the most frequently adulterated herbal medicines because of their confusability of terms in the ancient writings and the similarity of morphological features of dried herbal products. The major adulterant is Aristolochia manshuriensis (Guanmutong) which has a serious safety concern with its toxicity. To ensure the safety and quality of the two herbal medicines, it is necessary to discriminate the toxic adulterant from authentic species. The aim of this study is to develop SCAR markers and to establish the multiplex-SCAR assay for discrimination of four plant species related to Tetrapanacis Medulla and Akebiae Caulis. Methods : ITS regions of fifteen samples of four species (Tetrapanax papyrifer, Fatsia japonica, Aristolochia manshuriensis, and Akebia quinata) collected from different sites were amplified and sequenced. Fifteen obtained ITS sequences were aligned and analysed for the detection of species-specific sequence variations. The SCAR markers were designed based on the sequence alignments and then, multiplex-SCAR assay enhancing rapidity was optimized. Results : ITS sequences clearly distinguished the four species at the species level. The developed SCAR markers and multiplex-SCAR assay were successfully discriminated four species and detected the adulteration of commercial product samples by comparison of the amplified DNA fragment sizes. Conclusions : These SCAR markers and multiplex-SCAR assay are a rapid, simple, and reliable method to identify the authentic Tetrapanacis Medulla and Akebiae Caulis from adulterants. These genetic tools will be useful to ensure the safety and to standardize the quality of the two herbal medicines.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.30 no.6
• /
• pp.1115-1130
• /
• 2020

Modern vehicles are equipped with a number of ECUs(Electronic Control Units), and ECUs can control vehicles efficiently by communicating each other through CAN(Controller Area Network). However, CAN bus is known to be vulnerable to cyber attacks because of the lack of message authentication and message encryption, and access control. To find these security issues related to vehicle hacking, CAN Fuzzing methods, that analyze the vulnerabilities of ECUs, have been studied. In the existing CAN Fuzzing methods, fuzzing inputs are randomly generated without considering the structure of CAN messages transmitted by ECUs, which results in the non-negligible fuzzing time. In addition, the existing fuzzing solutions have limitations in how to monitor fuzzing results. To deal with the limitations of CAN Fuzzing, in this paper, we propose a Non-Random CAN Fuzzing, which consider the structure of CAN messages and systematically generates fuzzing input values that can cause malfunctions to ECUs. The proposed Non-Random CAN Fuzzing takes less time than the existing CAN Fuzzing solutions, so it can quickly find CAN messages related to malfunctions of ECUs that could be originated from SW implementation errors or CAN DBC(Database CAN) design errors. We evaluated the performance of Non-Random CAN Fuzzing by conducting an experiment in a real vehicle, and proved that the proposed method can find CAN messages related to malfunctions faster than the existing fuzzing solutions.

• Journal of Intelligence and Information Systems
• /
• v.28 no.4
• /
• pp.365-385
• /
• 2022

The easy payment service is a payment and remittance service that uses a simple authentication method. As online transactions have increased due to COVID-19, the use of an easy payment service is increasing. At the same time, electronic financial industries such as Naver Pay, Kakao Pay, and Toss are diversifying the competition structure of the easy payment market; meanwhile overseas fintech companies PayPal and Alibaba have a unique market share in their own countries, while competition is intensifying in the domestic easy payment market, as there is no unique market share. In this study, the participants in the easy payment market were classified as electronic financial companies, mobile phone manufacturers, and financial companies, and a SWOT analysis was conducted on the representative services in each industry. The analysis examined the user reviews of Google Play Store via a topic modeling analysis, and it employed positive topics as strengths and negative topics as weaknesses. In addition, topic modeling was conducted by dividing news articles into political, economic, social, and technology (PEST) articles to derive the opportunities and threats to easy payment services. Through this research, we intend to confirm the service capabilities of easy payment companies and propose a service activation strategy that allows gaining the upper hand in the market.