• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.1
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• pp.84-90
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• 2014

Secret communication has developed from analogue communication to digital one. Secret communication which is based on digital communication has been designed succeeding safety of one-time pad. One-time pad's safety is attributed to the security of secret key's mutual storage and mutual synchronization that is the key's interchange basis is one of the essential factors. This manuscript examines mathematical stability of BB84 algorithm which is one of the quantum cryptography system, and conducts transmission of quantum key. The created key suggests One-time Pad algorithm which interchanges ciphertext implemented AES's 64th round.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1991.10a
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• pp.100-102
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• 1991

In this paper, we use LFSR(Linear Feedback Shift Register) as a kind of pseudo-random one-time pad. Key generator is constructed using r separate LFSR's with IP(Irreducible Polynominal) which are relatively prime. Key generated in this method has high linear complexity. And also, file cryptosystem for file encryption and decryption is constructed.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.5
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• pp.51-60
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• 2015

As electronic commerce service became more popular, information equivalent to currency prevails in network. Accordingly, hacking into network often occurs and thus OTP (One-Time-Password) has emerged as an alternative secondary security system. However, weakness has been found in even existing One-Time Password that used to be considered 'perfect'. Therefore, it becomes very urgent to have an additional security countermeasure. As security recommendation is not considered as solution anymore, more specific plan becomes necessary. The present study proposes PKI coordinates technique-based OTP (One-Time-Pad) for a safe key transmission in E-commerce.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.2 no.1
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• pp.5-21
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• 2008

In order to securely transmit multicast data packets in a mobile environment where frequent join/leave events are a characteristic of the environment, there is a need for a new secure and efficient group key management solution. We propose a secure group key generation/distribution solution providing scalability and reliability. Using this solution, when a mobile node, which is in a multicast session, enters a new domain, the agent of the domain joins the multicast session and coordinates its data packets with the mobile node. The agent encrypts and transmits subsequent data packets to the mobile node, using a local one-time pad key. This key is generated with FI sequences, enabling the mobile node to regenerate the same data packet, based on the information sent by the agent. Our performance analysis demonstrates that the proposed solution can significantly reduce the number of key generations and distributions, when it is applied to the hierarchical mobile IPv6 network.

• Journal of Digital Convergence
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• v.11 no.11
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• pp.389-395
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• 2013

As fusing IT and medical technique, the number of patients who adhere medical equipment inside of them is increasing. However there is a problem of for the third person to tap or modulate the patient's biometric data viciously. This paper suggests quantum encryption-based key distribution model to share key for the third person not to tap or modulate the patient's biometric data between patient and hospital staff. The proposed model uses one-time pad key that shares key sending random bits not direct sending message of quantum data. Also, it guarantees patient's anonymity because the biometric data of injected-device in the body doesn't be exposed unnecessarily.

• The KIPS Transactions:PartC
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• v.18C no.5
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• pp.327-330
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• 2011

After releasing the smart phone equipping the strong computational capability compared to traditional mobil phone, a field of services, which is available on the personal computers, is expanded to smart phone. The development of technology reduces the limited service utilization on time and space but it has a venerability exposing an information to malicious user. Especially we need to more attention when using the financial services which communicate the user's private information. To solve the security problem, OTP(One Time Pad), which uses a private key for a session, is recommended. OTP techniques in smart phone having focused on traditional environments have been proposed and implemented. However, security over mobile environments is more vulnerable to attack and has restriction on resources than traditional system. For this reason, definition of proper conceptual OTP on smart phone is required. In the paper, we present the L-OTP(Location-OTP) protocol, using T-OTP(Time One Time Pad) technique with location information. Proposal generates the OTP using unique location information which is obtained in smart phone.

• Journal of the Korea Society of Computer and Information
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• v.16 no.11
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• pp.163-171
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• 2011

Because RFID systems use radio frequency, they have many security problems such as eavesdropping, location tracking, spoofing attack and replay attack. So, many mutual authentication protocols and cryptography methods for RFID systems have been proposed in order to solve security problems, but previous proposed protocols using AES(Advanced Encryption Standard) have fixed key problem and security problems. In this paper, we analyze security of proposed protocols and propose our protocol using OTP(One-Time Pad) and AES to solve security problems and to reduce hardware overhead and operation. Our protocol encrypts data transferred between RFID reader and tag, and accomplishes mutual authentication by one time random number to generate in RFID reader. In addition, this paper presents that our protocol has higher security and efficiency in computation volume and process than researched protocols and S.Oh's Protocol. Therefore, our protocol is secure against various attacks and suitable for lightweight RFID tag system.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.7 no.2
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• pp.27-42
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• 1997

We propose a new authentication and key distribution protocol which is efficient and reliable for password-based systems. Various guessing attacks have been detected in applying conventional protocols to the password-based systems and additional overheads have been made in refined protocols to defeat those attacks. Using a one-time pad and a strong hash function, our proposed protocol promotes reliability and efficiency. Compared with other protocols, our protocol is secure against various protocol attacks including guessing attacks. In addition, this protocol is efficient in reducing communication and computation costs.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.5
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• pp.2698-2717
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• 2019

This paper proposes a multi-stage encryption technique to enhance the level of secrecy of image to facilitate its secured transmission through the public network. A great number of researches have been done on image secrecy. The existing image encryption techniques like visual cryptography (VC), steganography, watermarking etc. while are applied individually, usually they cannot provide unbreakable secrecy. In this paper, through combining several separate techniques, a hybrid multi-stage encryption technique is proposed which provides nearly unbreakable image secrecy, while the encryption/decryption time remains almost the same of the exiting techniques. The technique consecutively exploits VC, steganography and one time pad (OTP). At first it encrypts the input image using VC, i.e., splits the pixels of the input image into multiple shares to make it unpredictable. Then after the pixel to binary conversion within each share, the exploitation of steganography detects the least significant bits (LSBs) from each chunk within each share. At last, OTP encryption technique is applied on LSBs along with randomly generated OTP secret key to generate the ultimate cipher image. Besides, prior to sending the OTP key to the receiver, first it is converted from binary to integer and then an asymmetric cryptosystem is applied to encrypt it and thereby the key is delivered securely. Finally, the outcome, the time requirement of encryption and decryption, the security and statistical analyses of the proposed technique are evaluated and compared with existing techniques.

• Journal of information and communication convergence engineering
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• v.20 no.4
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• pp.242-249
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• 2022

Classical cryptography with complex computations has recently been utilized in the latest computing systems to create secret keys. However, systems can be breached by fast-measuring methods of the secret key; this approach does not offer adequate protection when depending on the computational complexity alone. The laws of physics for communication purposes are used in quantum computing, enabling new computing concepts to be introduced, particularly in cryptography and key distribution. This paper proposes a quantum computing lattice (CQL) mechanism that applies the BB84 protocol to generate a quantum key. The generated key and a one-time pad encryption method are used to encrypt the message. Then Babai's algorithm is applied to the ciphertext to find the closet vector problem within the lattice. As a result, quantum computing concepts are used with classical encryption methods to find the closet vector problem in a lattice, providing strength encryption to generate the key. The proposed approach is demonstrated a high calculation speed when using quantum computing.