• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.3
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• pp.627-632
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• 2005

Almost all network systems provide an authentication mechanism based on user ID and password. In such system, it is easy to obtain the user password using a sniffer program with illegal eavesdropping. The one-time password and challenge-response method are useful authentication schemes that protect the user passwords against eavesdropping. In client/ server environments, the one-time password scheme using time is especially useful because it solves the synchronization problem. It is the stability that is based on Square Root problem, and we would like to suggest OPI(One Pass Identification), enhancing the stability for all of the well-known attacks by now including Free-playing attack, off-line Literal attack, Server and so on. OPI does not need to create the special key to read the password. OPI is very excellent in identifying the approved person within a very short time.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.299-302
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• 2011

Recently, Voice over Internet protocol(VoIP) in IP-based wired and wireless voice, as well as by providing multimedia information transfer. Wired and wireless VoIP is easy on illegal eavesdropping of phone calls and VoIP call control signals on the network. In addition, service misuse attacks, denial of service attacks can be targeted as compared to traditional landline phones, there are several security vulnerabilities. In this paper, VoIP equipment in order to obtain information on the IP Phone is scanning. And check the password of IP Phone, and log in successful from the administrator's page. Then after reaching the page VoIP IP Phone Administrator Settings screen, phone number, port number, certification number, is changed. In addition, IP Phones that are registered in the administrator page of the call records check and personal information is the study of hacking.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.9 no.2
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• pp.83-92
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• 1999

Cryptography techniques can prevent eavesdroppers from maliciously intercepting or modifying sensitive information. however misuses of encryption may cause other problems First if the encryption key is lost or damaged even an authorized access to the original data will be denied. Second criminals can prevent authorized law enforcement officers from examining the necessary information by using the strong encrypted data can provide solutions for the situations. In this paper we propose a new key escrow system based on the ElGamal cryptosystem. Our system provide time-bound eavesdropping under court authorized permission protect from trustee's cheating and prevent user's shadow public key generation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.10a
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• pp.469-471
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• 2021

As wireless communication technology advances to ensure high accuracy and safety at high speeds, research and development of Visible Light Communication (VLC) technology has been accelerated as an alternative to traditional radio frequency (RF) technology. As the radio spectrum of RF communication becomes more congested and demand for bandwidth continues to increase, VLCs that can use unlicensed frequency band are proposed as a solution. However, VLC channels have broadcasting characteristics that make them easily exposed to eavesdropping and jamming attacks, and are vulnerable to MITM (Man-In-The-Middle) due to their line of sight (LOS) propagation characteristics. These attacks on VLC channels compromise the confidentiality, integrity, and availability of communications links and data, resulting in higher data retransmission rates, reducing throughput and increasing power consumption, resulting in lower data transmission efficiency. In this work, we model vulnerable VLC channels to analyze the impact of attacks and communications vulnerabilities by malicious jammers.

• Journal of Practical Engineering Education
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• v.15 no.3
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• pp.641-647
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• 2023

In the fintech environment, ensuring secure financial transactions with smartphones requires authenticating the device owner. Smartphone authentication techniques encompass a variety of approaches, such as passwords, biometrics, SMS authentication, and more. Among these, password-based authentication is commonly used and highly convenient for user authentication. Although it is a simple authentication mechanism, it is susceptible to eavesdropping and keylogging attacks, alongside other threats. Security keypads have been proposed to address vulnerabilities in password input on smartphones. One such innovation is a group keypad, resistant to attacks that guess characters based on touch location. However, improvements are needed for user convenience. In this study, we aim to propose a method that enhances convenience while being resistant to eavesdropping and recording attacks on the existing group keypad. The proposed method uses new signs to allow users to verify instead of the last character confirmation easily and employs dragging-to-touch for blocking recording attacks. We suggest diverse positioning methods tailored for domestic users, improving efficiency and security in password input compared to existing methods.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2002.11a
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• pp.473-476
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• 2002

본 논문에서는 ad-hoc wireless network에서 상호간의 사전지식 없이 상대편을 authenticate하는 프로토콜을 제시한다. 기존에 Dirk Balfanz et al에 의해 제시된 변형된interactive Guy Fawkes protocol은 해쉬함수의, 전달하고자 하는 메시지와 그 authenticator의 해쉬값을 보내고, 다음 단계에서 그 원본을 밝히는 원리를 이용한 것으로, PKI 없이 해쉬함수 만으로 상호인증과 메시지의 무결성을 보장함으로써 전반적인 ID 체계와 public key encryption, decryption 연산에 대한 부담을 덜었다. 하지만, 이것은 여전히 eavesdropping같은 passive attack에 노출되어 있다[1]. 본 논문에서는 zero-knowledge 기반의 프로토콜을 이용하여 상호 정보를 교환할 수 없는 환경에서도 안전하게 상호 authentication을 가능하게 하는 방법을 제시한다.

• Journal of information and communication convergence engineering
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• v.9 no.6
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• pp.683-688
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• 2011

The wireless sensor network (WSN) is well known for an enabling technology for the ubiquitous environment such as real-time surveillance system, habitat monitoring, home automation and healthcare applications. However, the WSN featuring wireless communication through air, a resource constraints device and irregular network topology, is threatened by malicious nodes such as eavesdropping, forgery, illegal modification or denial of services. For this reason, security in the WSN is key factor for utilizing the sensor network into the commercial way. There is a series of symmetric cryptography proposed by laboratory or industry for a long time. Among of them, recently proposed HUMMINGBIRD algorithm, motivated by the design of the well-known Enigma machine, is much more suitable to resource constrained devices, including smart card, sensor node and RFID tags in terms of computational complexity and block size. It also provides resistance to the most common attacks such as linear and differential cryptanalysis. In this paper, we implements ultra-lightweight cryptography, HUMMINGBIRD algorithm into the resource constrained device, sensor node as a perfectly customized design of sensor node.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.3
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• pp.1193-1209
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• 2015

Network coding is promising to maximize network throughput and improve the resilience to random network failures in various networking systems. In this paper, the problem of providing efficient confidentiality for practical network coding system against a global eavesdropper (with full eavesdropping capabilities to the network) is considered. By exploiting a novel combination between the construction technique of systematic Maximum Distance Separable (MDS) erasure coding and traditional cryptographic approach, two efficient schemes are proposed that can achieve the maximum possible rate and minimum encryption overhead respectively on top of any communication network or underlying linear network code. Every generation is first subjected to an encoding by a particular matrix generated by two (or three) Vandermonde matrices, and then parts of coded vectors (or secret symbols) are encrypted before transmitting. The proposed schemes are characterized by tunable and measurable degrees of security and also shown to be of low overhead in computation and bandwidth.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.28 no.11
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• pp.748-751
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• 2015

Sound Masking System technology as by sound the same on all bands and artificially generates a constant sound shield People want to hear or recognize the people with the noise generated from the interior of the way. Prevent hearing or prevent recognition by using the technology to control the audible frequency band Continue to emit constant and uniform shielding sound audible frequency band Even the security content of speech (20 Hz~20 KHz). That interception laser eavesdropping, internal solicitations, during recording Or delay the decoding was a result of the effect of interference calculated Experience noise disturbance index is applied around the Stress Index is the average index is 10.16 was a luxury for the average index is then applied to the index 3.07 Noise is significantly lower stress level has improved noise conditions.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.1
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• pp.422-436
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• 2020

In this paper, we investigate the impact of antenna correlation on secure transmission in a multi-eavesdropper single-input multiple-output (SIMO) system, where the receiver and eavesdroppers are equipped with correlated antennas. Based on the practical passive eavesdropping system, the new closed-form expressions of secrecy outage probability (SOP) and non-zero secrecy capacity probability are derived to explore the effect of antenna correlation on the system with multiple eavesdroppers. To further analyze the secrecy performance of the investigated system, we theoretically derive the expression of asymptotic SOP to clearly show the diversity order and array gain. Finally, Monte Carlo simulations verify the effectiveness of our theoretical results.