• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.30 no.4
• /
• pp.647-656
• /
• 2020

Recently, there has been an increasing number of cases in which important data (personal information, technology, etc.) of national and public institutions are leaked to the outside world. Surveys show that the largest cause of such leakage accidents is "insiders." Insiders of organization with the most authority can cause more damage than technology leaks caused by external attacks due to the organization. This is due to the characteristics of insiders who have relatively easy access to the organization's major assets. This study aims to present an optimized property selection model for detecting such abnormalities through supervised learning algorithms among machine learning techniques using actual data such as CrossNet data transfer system transmission log, e-mail transmission log, and personnel information, which safely transmits data between separate areas (security area and non-security area) of the business network and the Internet network.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.17 no.9
• /
• pp.2183-2190
• /
• 2013

Container Security Device (ConTracer) which is suggested in this study is to monitor temperature, humidity, and impact inside of the container while the container is transported. ConTracer could also give information to users when a door of the container is opened over 2 inch within 1 second. Additionally, GPS/GLONASS based global position and status information about container are transmitted to a remote server using IoT (Internet of Things) based communication. In this research, we are looking into the development trend of global container security devices; and applying ConTracer to real freight transport from domestic to overseas using Global Roaming Service which is offered for domestic Mobile Communication Companies as well. As a result, we estimate the performance of ConTracer and verify it.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.27 no.2
• /
• pp.353-360
• /
• 2017

The Internet of Things(IoT) security has more need than a technical problem as it needs series of regulations and faultless security system for common purposes. So, this study proposes an efficient key management in order that can be trusted IoT data in cloud computing. In contrast with a key distribution center of existing sensor networks, the proposed a federation key management of cloud proxy key server is not central point of administration and enables an active key recovery and update. The proposed key management is not a method of predetermined secret keys but sharing key information of a cloud proxy key server in autonomous cloud, which can reduce key generation and space complexity. In addition, In contrast with previous IoT key researches, a federation key of cloud proxy key server provides an extraction ability from meaningful information while moving data.

• Spatial Information Research
• /
• v.22 no.6
• /
• pp.45-54
• /
• 2014

Establishment of safety net for the socially disadvantaged attracts large attention because of the recent crime increasing against vulnerable groups. For the successful establishment of social safety net, the test-bed for evaluation and realization of crime-related research results is required. However, previous R&D test-bed projects such as The Korean Land Specialization Program or U-Eco City project remains only to the stage of verification. Therefore, there are limitedness for realization of result technologies or sustainable operation & management of test-bed after projects finished. So, sustainable operation & management system and guideline of test-bed are necessary. Therefore, this study reviews the strengths and weaknesses of existing test-bed cases and intelligent security researches. After reviewing, the concept of a Intelligent Security Test-bed is established and appropriate test-bed selection criteria is also suggested. Based on objective criteria, selected test-bed can achieve sustainable management even after finishing the project and contribute the construction of standard model for citizen's safety.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.29 no.6
• /
• pp.1383-1392
• /
• 2019

Adversarial attack, which geneartes adversarial data to make target model misclassify the input data, is able to confuse real life applications of classification models and cause severe damage to the classification system. An Black-box adversarial attack learns a substitute model, which have similar decision boundary to the target model, and then generates adversarial data with the substitute model. Jacobian-based data augmentation is used to synthesize the training data to learn substitutes, but has a drawback that the data synthesized by the augmentation get distorted more and more as the training loop proceeds. We suggest data augmentation with 'decay factor' to alleviate this problem. The result shows that attack success rate of our method is higher(around 8.5%) than the existing method.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.28 no.4
• /
• pp.809-826
• /
• 2018

The entropy evaluation method for noise sources is one of the evaluation methods for the random number generator that is the essential element of modern cryptographic systems and cryptographic modules. The primary entropy evaluation methods outside of the country are more suitable to apply to hardware noise sources than software noise sources, and there is a difficulty in quantitative evaluation of entropy by software noise source. In this paper, we propose an entropy evaluation method that is suitable for software noise sources, considering characteristics of software noise sources. We select time-dependent noise sources that are software noise sources of Windows OS, and the heuristic analysis and experimental analysis are performed considering the characteristics of each time-dependent noise source. Based on these analyses, we propose an entropy harvest method from the noise source and the min-entropy estimation method as the entropy evaluation method for time-dependent noise sources. We also show how to use our entropy evaluation method in the Conditioning Component described in SP 800-90B of NIST(USA).

• Journal of the Korea Society of Computer and Information
• /
• v.24 no.10
• /
• pp.25-32
• /
• 2019

In this paper, we propose a method to apply the attack surface expansion through decoy traps to a protected server network. The network consists of a large number of decoys and protected servers. In the network, each protected server dynamically mutates its IP address and port numbers based on Hidden Tunnel Networking that is a network-based moving target defense scheme. The moving target defense is a new approach to cyber security and continuously changes system's attack surface to prevent attacks. And, the attack surface expansion is an approach that uses decoys and decoy groups to protect attacks. The proposed method modifies the NAT table of the protected server with a custom chain and a RETURN target in order to make attackers waste all their time and effort in the decoy traps. We theoretically analyze the attacker success rate for the protected server network before and after applying the proposed method. The proposed method is expected to significantly reduce the probability that a protected server will be identified and compromised by attackers.

• International Journal of Computer Science & Network Security
• /
• v.21 no.12
• /
• pp.235-247
• /
• 2021

Today, the cloud computing has become a major demand of many organizations. The major reason behind this expansion is due to its cloud's sharing infrastructure with higher computing efficiency, lower cost and higher fle3xibility. But, still the security is being a hurdle that blocks the success of the cloud computing platform. Therefore, a novel Multi-tenant Decentralized Information Flow Control (MT-DIFC) model is introduced in this research work. The proposed system will encapsulate four types of entities: (1) The central authority (CA), (2) The encryption proxy (EP), (3) Cloud server CS and (4) Multi-tenant Cloud virtual machines. Our contribution resides within the encryption proxy (EP). Initially, the trust level of all the users within each of the cloud is computed using the proposed two-stage trust computational model, wherein the user is categorized bas primary and secondary users. The primary and secondary users vary based on the application and data owner's preference. Based on the computed trust level, the access privilege is provided to the cloud users. In EP, the cipher text information flow security strategy is implemented using the blowfish encryption model. For the data encryption as well as decryption, the key generation is the crucial as well as the challenging part. In this research work, a new optimal key generation is carried out within the blowfish encryption Algorithm. In the blowfish encryption Algorithm, both the data encryption as well as decryption is accomplishment using the newly proposed optimal key. The proposed optimal key has been selected using a new Self Improved Cat and Mouse Based Optimizer (SI-CMBO), which has been an advanced version of the standard Cat and Mouse Based Optimizer. The proposed model is validated in terms of encryption time, decryption time, KPA attacks as well.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.28 no.6
• /
• pp.1415-1425
• /
• 2018

MMORPG genre is based on the belief that all users in virtual world are equal. All users are able to obtain the corresponding wealth or status as they strive under the same resource, time. However, game bot is the main factor for harming this fair competition, causing benign gamers to feel a relative deprivation and deviate from the game. Game bots mainly form GFG(Gold Farming Group), which collects the goods in the game indiscriminately and adversely affects the economic system of the game. A general game bot detection algorithm is useful for detecting each bot, but it only covers few portions of GFG, not the whole, so it needs a wider range of detecting method. In this paper, we propose a method of detecting GFG based on items used in MMORPG genre. Several items that are mainly traded in the game were selected and the flows of those items were represented by a network. We Identified the characteristics of exchanging items of GFG bots and can identify the GFG's item trade network with real datasets from one of the popular online games.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.14 no.4
• /
• pp.13-23
• /
• 2004

Proxy signature scheme based on delegation of warrant is studied in these days. Proxy signature is a signature scheme that the original signer delegates his signing warrant to the proxy signer, and the proxy signer creates a signature on behalf of the original signer. For using this scheme, the security for Protecting from the forgeability or misuse is necessary. There are several security requirements for using the proxy signature schemes. In this paper we suggest the proxy-register protocol scheme that original signer registers to the verifier about the proxy related information. In our scheme, verifier verifies the signature that original signer creates about the proxy information and sets the warrant of proxy signer, validity period for proxy signature and some limitation. Finally, we will show the advantages of our suggestion by comparing with the previous proxy signature schemes.