• KSII Transactions on Internet and Information Systems (TIIS)
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• v.4 no.5
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• pp.968-988
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• 2010

Anonymous hierarchical identity based encryption (HIBE) is an extension of identity based encryption (IBE) that can use an arbitrary string like an e-mail address for a public key, and it additionally provide the anonymity of identity in ciphertexts. Using the anonymous HIBE schemes, it is possible to construct anonymous communication systems and public key encryption with keyword search. This paper presents an anonymous HIBE scheme with constant size ciphertexts under prime order symmetric bilinear groups, and shows that it is secure under the selective security model. Previous anonymous HIBE schemes were constructed to have linear size ciphertexts, to use composite order bilinear groups, or to use asymmetric bilinear groups that is a special type of bilinear groups. Our construction is the first efficient anonymous HIBE scheme that has constant size ciphertexts and that uses prime order symmetric bilinear groups. Compared to the previous scheme of composite order bilinear groups, ours is ten times faster. To achieve our construction, we first devise a novel cancelable random blinding technique. The random blinding property of our technique provides the anonymity of our construction, and the cancellation property of our technique enables decryption.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.12 no.4
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• pp.67-76
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• 2002

Kerberos is designed to provide strong authentication between client and application servers which are working in distributed network environment by using symmetric-key cryptography, and supposed to trust other systems of the realm. In this paper, we design an efficient and strong authentication mechanism by introducing the public/private-key to Kerberos. In the mechanism to make a system more secure, the value of the session key is changed everytime using MAC(message authentication code) algorithm with the long-term key for user-authentication and a random number exchanged through the public key. Also, we employ a mutual authentication method, which is used on challenge-response mechanism based on digital signatures, to improve trust between realms, and present a way of reducing the number of keys by simplifying authentication steps.

• Journal of the Korea Society of Computer and Information
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• v.3 no.4
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• pp.91-96
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• 1998

In this paper we designed a secure client-server system to be able to protect messages between client and server using cryptography We authenticated each other using a asymmetric encryption algorithm on the logon procedure and minimized the time to encrypt and decrypt messages using a symmetric encryption algorithm on exchanging messages. We proved that it is possible to make a digital signature on our secure client-server system. And we suggested the efficient key management method to generate and distribute cryptograpic key securely.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.46 no.7
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• pp.602-609
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• 2018

This paper proposes the hybrid crypto-system for fast video data encryption of UAV(Unmanned Aerial Vehicle) under the LTE(Long-Term Evolution) wireless communication environment. This hybrid crypto-system is consisted of ECC(Elliptic Curve Cryptography) public key algorithm and LEA(Light-weight Encryption Algorithm) symmetric key algorithm. ECC is a faster public key algorithm with the same security strength than RSA(Rivest Shamir Adleman), and Korean standard LEA with the same key size is also a faster symmetric key algorithm than AES(Advances Encryption Standard). We have implemented this hybrid crypto-system using OpenSSL, OpenCV and Socket programs under the Swarm 8-UAV. We have shown the efficient adaptability of this hybrid crypto-system for the real-time swarm UAV through the experiments under the LTE communication environment.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.10
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• pp.2192-2198
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• 2012

VANET is a network environment which provides the communication between vehicles and between vehicle and RSU using wireless communication. VANET is very important to protect safety and life of people. Because of that, security is considered enough and certification is very important when messages exchanged between vehicles. Recently, Zhang proposed using Diffie-Hellman key exchange protocol that is method exchanging messages in VANET system through RAISE. But this is many problems on weakness from various attacks. In this paper, proposed the method that establish symmetric key using ECDH key exchange protocol and confirm safety and time spending that generate key and exchange through comparison.

• Journal of Digital Convergence
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• v.12 no.10
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• pp.253-258
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• 2014

Recently, the development of cloud computing technology is developed as soon as smartphones is increases, and increased that users want to receive big data service. Hadoop framework of the big data service is provided to hadoop file system and hadoop mapreduce supported by data-intensive distributed applications. But, smpartphone service using hadoop system is a very vulnerable state to data authentication. In this paper, we propose a initial authentication protocol of hadoop system assisted by smartphone service. Proposed protocol is combine symmetric key cryptography techniques with ECC algorithm in order to support the secure multiple data processing systems. In particular, the proposed protocol to access the system by the user Hadoop when processing data, the initial authentication key and the symmetric key instead of the elliptic curve by using the public key-based security is improved.

• Journal of Korea Society of Digital Industry and Information Management
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• v.12 no.2
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• pp.41-49
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• 2016

Lossless encryption methods are more applicable than lossy encryption methods when marginal distortion is not tolerable. In this research, the author propose a novel lossless symmetric key encryption/decryption technique. In the proposed algorithm, the image is transformed into the frequency domain using the lifting wavelet transform, then the image sub-bands are encrypted in a such way that guarantees a secure, reliable, and an unbreakable form. The encryption involves scattering the distinguishable frequency data in the image using a reversible weighting factor amongst the rest of the frequencies. The algorithm is designed to shuffle and reverse the sign of each frequency in the transformed image before the image frequencies are transformed back to the pixel domain. The results show a total deviation in pixel values between the original and encrypted image. The decryption algorithm reverses the encryption process and restores the image to its original form. The proposed algorithm is evaluated using standard security and statistical methods; results show that the proposed work is resistant to most known attacks and more secure than other algorithms in the cryptography domain.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.8
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• pp.1519-1527
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• 2007

In order to combat the security threats that sensor networks are exposed to, a cryptography protocol is implemented at sensor nodes for point-to-point encryption between nodes. Given that nodes have limited resources, symmetric cryptography that is proven to be efficient for low power devices is implemented. Data protection is integrated into a sensor's packet by the means of symmetric encryption with the Dragon stream cipher and incorporating the newly designed Dragon-MAC Message Authentication Code. The proposed algorithm was designed to employ some of the data already computed by the underlying Dragon stream cipher for the purpose of minimizing the computational cost of the operations required by the MAC algorithm. In view that Dragon is a word based stream cipher with a fast key stream generation, it is very suitable for a constrained environment. Our protocol regarded the entity authentication and message authentication through the implementation of authenticated encryption scheme in wireless sensor nodes.

• Convergence Security Journal
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• v.19 no.5
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• pp.47-53
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• 2019

Network-based sharing of information has evolved into a cloud service environment today, increasing its number of users rapidly, but has become a major target for network-based illegal attackers.. In addition, IP spoofing among attackers' various attack techniques generally involves resource exhaustion attacks. Therefore, fast detection and response techniques are required. The existing detection method for IP spoofing attack performs the final authentication process according to the analysis and matching of traceback information of the client who attempted the connection request. However, the simple comparison method of traceback information may require excessive OTP due to frequent false positives in an environment requiring service transparency. In this paper, symmetric key cryptography based on traceback information is used as mutual authentication information to improve this problem. That is, after generating a traceback-based encryption key, mutual authentication is possible by performing a normal decryption process. In addition, this process could improve the overhead caused by false positives.

• Journal of Industrial Convergence
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• v.18 no.5
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• pp.23-29
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• 2020

The Internet of things (IoT) is the extension of Internet connectivity into various devices and everyday objects. Embedded with electronics, Internet connectivity and other forms of hardware. The IoT poses significant risk to the entire digital ecosystem. This is because so many of these devices are designed without a built-in security system to keep them from being hijacked by hackers. This paper proposed a mutual authentication protocol for IoT Devices using symmetric-key algorithm. The proposed protocol use symmetric key cryptographic algorithm to securely encrypt data on radio channel. In addition, the secret key used for encryption is random number of devices that improves security by using variable secret keys. The proposed protocol blocked attacker and enabled legal deives to communicate because only authenticated devices transmit data by a mutual authentication protocol. Finally, our scheme is safe for attacks such as eavesdropping attack, location tracking, replay attack, spoofing attack and denial of service attack and we confirmed the safety by attack scenario.