• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.7
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• pp.3720-3746
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• 2017

At present, numerous hospitals and medical institutes have implemented Telecare Medicine Information Systems (TMIS) with authentication protocols to enable secure, efficient electronic transactions for e-medicine. Numerous studies have investigated the use of authentication protocols to construct efficient, robust health care services, and recently, Liu et al. presented an authenticated key agreement mechanism for TMIS. They argued that their mechanism can prevent various types of attacks and preserve a secure environment. However, we discovered that Liu et al.'s mechanism presents some vulnerabilities. First, their mechanism uses an improper identification process for user biometrics; second, the mechanism is not guaranteed to protect against server spoofing attacks; third, there is no session key verification process in the authentication process. As such, we describe how the above-mentioned attacks operate and suggest an upgraded security mechanism for TMIS. We analyze the security and performance of our method to show that it improves security relative to comparable schemes and also operates in an efficient manner.

• ETRI Journal
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• v.35 no.4
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• pp.726-729
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• 2013

For secure multimedia communications, existing encryption techniques use an online session key for the key exchange, for which key size is limited to less than 10 digits to accommodate the latency condition caused by user devices only being able to handle low computational loads. This condition results in poor security of recorded encrypted data. In this letter, we propose a packet key scheme that encrypts real-time packets using a different key per packet for multimedia applications. Therefore, a key of a relatively small size can provide after-transmission confidentiality to data of a real-time session.

• The KIPS Transactions:PartC
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• v.12C no.4 s.100
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• pp.481-488
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• 2005

The Mobile W provides an efficient and scalable mechanism for host mobility within the Internet. However, the mobility implies higher security risks than static operations in fixed networks. In this paper, the Mobile IP has been adapted to allow AAA protocol that supports authentication, authorization, and accounting(AAA) for security and collection for accounting information of network usage by mobile nodes(MNs). For this goal, we Propose the boundary tone overlapped network structure while solidifying the security for the authentication of an MN. That is, the Proposed scheme delivers the session keys at the wired link for MN's security instead of the wireless one, so that it provides a fast and seamless handoff mechanism. According to the analysis of modeling result, the proposed mechanism compared to the existing session key reuse method is up to about $40\%$ better in terms of normalized surcharge for the handoff failure rate that considers handoff total time.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.20 no.1
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• pp.41-50
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• 2010

This paper proposes a mutual identification and session key exchange scheme in secure vehicular communication based on the group signature. In VANETs, security requirements such as authentication, conditional privacy, non-repudiation, and confidentiality are required to satisfy various vehicular applications. However, existing VANET security methods based on the group signature do not support a mutual identification and session key exchange for data confidentiality. The proposed scheme allows only one credential to authenticate ephemeral Diffie-Hellman parameters generated every key exchange session. Our scheme provides a robust key exchange and reduces storage and communication overhead. The proposed scheme also satisfies security requirements for various application services in VANETs.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.29 no.1
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• pp.235-255
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• 2019

Recent technological advances and industry changes, the game industry is maximizing fun by supporting cross-play that can be enjoyed by different platform users in PC, Mobile and Console games. If the boundaries are lost through the cross play, unexpected security threats can occur due to new services, even if existing security is maintained above a certain level. The existing online game security researches are mostly fraud detection that can occur in PC and mobile environment, but it is also necessary to study the security of the console game as cross play becomes possible. Therefore, this paper systematically identifies the security threats that can occur when enjoying cross play against console game users using STRIDE and LINDDUN threat modeling, derives security requirements using the international common evaluation standard.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.22 no.6
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• pp.1315-1324
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• 2012

Security visualization is a form of the data visualization techniques in the field of network security by using security-related events so that it is quickly and easily to understand network traffic flow and security situation. In particular, the security visualization that detects the abnormal situation of network visualizing connections between two endpoints is a novel approach to detect unknown attack patterns and to reduce monitoring overhead in packets monitoring technique. However, the session-based visualization doesn't notice a difference between normal traffic and attacks that they are composed of similar connection pattern. Therefore, in this paper, we propose an efficient session-based visualization method for analyzing and detecting between normal server activities and attacks by using the IP address splitting and port attributes analysis. The proposed method can actually be used to detect and analyze the network security with the existing security tools because there is no dependence on other security monitoring methods. And also, it is helpful for network administrator to rapidly analyze the security status of managed network.

• ETRI Journal
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• v.35 no.5
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• pp.889-899
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• 2013

Wireless sensor networks (WSNs) are used for many real-time applications. User authentication is an important security service for WSNs to ensure only legitimate users can access the sensor data within the network. In 2012, Yoo and others proposed a security-performance-balanced user authentication scheme for WSNs, which is an enhancement of existing schemes. In this paper, we show that Yoo and others' scheme has security flaws, and it is not efficient for real WSNs. In addition, this paper proposes a new strong authentication scheme with user privacy for WSNs. The proposed scheme not only achieves end-party mutual authentication (that is, between the user and the sensor node) but also establishes a dynamic session key. The proposed scheme preserves the security features of Yoo and others' scheme and other existing schemes and provides more practical security services. Additionally, the efficiency of the proposed scheme is more appropriate for real-world WSNs applications.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.22 no.1
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• pp.3-10
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• 2012

In this paper, we propose a fault injection attack on stream cipher A5/3 used in GSM. The fault assumption of this attack is based on that of fault injection attacks proposed in FDTC'05 and CISC-W'10. This attack is applicable to A5/3 supporting 64/128-bit session key, respectively, and can recover the session key by using a small number of fault injections. These works are the first known key recovery attack results on A5/3.

• Convergence Security Journal
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• v.22 no.4
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• pp.179-188
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• 2022

Password authentication schemes (PAS) are the most common mechanisms used to ensure secure communication in open networks. Mathematical-based cryptographic authentication schemes such as factorization and discrete logarithms have been proposed and provided strong security features, but they have the disadvantage of high computational and message transmission costs required to construct passwords. Fairuz et al. therefore argued for an improved cryptographic authentication scheme based on two difficult fixed issues related to session key consent using the smart card scheme. However, in this paper, we have made clear through security analysis that Fairuz et al.'s protocol has security holes for Privileged Insider Attack, Lack of Perfect Forward Secrecy, Lack of User Anonymity, DoS Attack, Off-line Password Guessing Attack.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.13 no.2
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• pp.115-125
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• 2003

As Web services are generally open for external uses and not filtered by Firewall, these result in attacker's target. Web attacks which exploit vulnerable web-applications and malicious users' requests cause economical and social problems. In this paper, we are modelling general web service usages based on user-web-session and detect anomal usages with Bayesian estimation method. Finally we propose SAD(Session Anomaly Detection) for detection unknown web attacks. To evaluate SAD, we made an experiment on attack simulation with web vulnerability scanner, whisker. The results show that the detection rate of SAD is over 90%, which is influenced by several features such as size of window or training set, detection filter method and web topology.