• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.11
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• pp.3182-3203
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• 2023

With the growing adoption of cloud-based technologies, maintaining the privacy and security of cloud data has become a pressing issue. Privacy-preserving encryption schemes are a promising approach for achieving cloud data security, but they require careful design and implementation to be effective. The integrated approach to cloud data security that we suggest in this work uses CogniGate: the orchestrated permissions protocol, index trees, blockchain key management, and unique Opacus encryption. Opacus encryption is a novel homomorphic encryption scheme that enables computation on encrypted data, making it a powerful tool for cloud data security. CogniGate Protocol enables more flexibility and control over access to cloud data by allowing for fine-grained limitations on access depending on user parameters. Index trees provide an efficient data structure for storing and retrieving encrypted data, while blockchain key management ensures the secure and decentralized storage of encryption keys. Performance evaluation focuses on key aspects, including computation cost for the data owner, computation cost for data sharers, the average time cost of index construction, query consumption for data providers, and time cost in key generation. The results highlight that the integrated approach safeguards cloud data while preserving privacy, maintaining usability, and demonstrating high performance. In addition, we explore the role of differential privacy in our integrated approach, showing how it can be used to further enhance privacy protection without compromising performance. We also discuss the key management challenges associated with our approach and propose a novel blockchain-based key management system that leverages smart contracts and consensus mechanisms to ensure the secure and decentralized storage of encryption keys.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.2
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• pp.77-82
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• 2013

PKMv2 security protocol was adopted by the WiMax2 mobile internet communication standard. A base station and a mobile station protect communication data using key based encryption according to the PKMv2 protocol. Consequently, each development of a base station and/or mobile station includes implement of the PKMv2 protocol, and the station must qualifies various interoperable tests. Furthermore, communication bandwidth of the station can be limited by the encryption module when the station implemented based on a low-performance processor. Thus, a correspondence measurement of the encryption module must be carried on the target processor. In this paper, we implement a testbed which affords throughput measurement as well as the interoperable tests by PKMv2.

• The KIPS Transactions:PartC
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• v.11C no.7 s.96
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• pp.971-980
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• 2004

This paper describes the design and implementation of the video conferencing system using public key infrastructure which is used for user authentication and encryption. Public key infrastructure reinforces the authentication process for conference participant, and the symmetric key system blocks malicious access to information and protect conference control information. This paper shows the implementation of the trans portation layer secure protocol in conformity with Korea public key authentication algorithm standard and symmetric encryption algorithm (DES, 3DES and AES) for media stream encryption. In this paper, we deal with two ways of protecting information : transportation layer secure protocol secures user authentication process and the conference control information; while public key-based authentication system protects personal information of users when they connect to the network. When distributing the session keys for encryption, Internet Key Exchange is used for P2P communication, and secure protocol is employed for 1 : N multi-user communication in the way of distributing the public key-based en-cryption key.

• 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.

• The Transactions of the Korea Information Processing Society
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• v.4 no.1
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• pp.195-208
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• 1997

ISDN is network which has been developed to integrate and transfer some information(data, video, voice). In the ISDN, security problem that threat and intrusion about important information resource increase because every information is transferred in the form of digital and access of network has patiency. In this paper, for protect important information resource, studied that apply application method and encryption system to ISDN, and system structure, ITU-T Q.931 protocol were analyzed, and proposable encryption key distribution protocol, call control with hybrid encryption system for user information privacy to provide security service.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.10 no.4
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• pp.33-46
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• 2000

IPsec is a protocol suite to protect the data communication between computers on internet and many VPNs(Virtual Private Networks) use IPsec protocol. IKE protocol is used to exchange keys in IPsec. Formal analysis method is used increasingly in computer science to increase the reliability of a system. In this paper, the IKE protocol is analyzed formally. This paper shows that IKE with Authentication with Signature and Authentication with Pre-Shared Key is safe, but Authentication with Public Key Encryption and A Revised Method of Authentication with Public Key Encryption are safe only with the assumption that a participant has the correct public key of the correspondent. To make sure that a participant has the correct public key of the correspondent, the usage of certificate is recommended.

• Journal of the Korea Convergence Society
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• v.2 no.2
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• pp.13-19
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• 2011

When the existing mail system is attacked by the third party, its content is exposed fully. To solve this problem, designed is the mail encryption system which can send and receive mail safely by the sessionkey. The mail receiver opens encrypted mail with the session key. In the traditional mail system, the server administrator can view mail content. However, in the proposed protocol, the server can only save mail as encryption/decryption is applied. Also, the ARIA encryption algorithm is used in encryption/decryption for better safety, and fast XOR operations are used to reduce the amount of operations.

• Journal of the Korea Society of Computer and Information
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• v.14 no.7
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• pp.81-88
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• 2009

Fingerprinting scheme is a technique which supports the copyright protection to track redistributors of digital content using cryptographic techniques. These schemes enable the original merchant to identify the original buyer of the digital data by embedding fingerprints into digital contents. Asymmetric property of fingerprinting schemes is important to keep the buyer's privacy. In this paper, we propose a symmetric encryption based fingerprinting protocol without trusted third party. Our scheme enables the reduction of computational costs for the encryption using symmetric key encryption scheme. Since a trusted third party doesn't take part in making the fingerprint of each buyer, the protocol doesn't need to control the trusted third party and it is more secure against collusion attack.

• Journal of the Korea Society of Computer and Information
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• v.22 no.9
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• pp.57-64
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• 2017

CCSDS Standard is widely used in the international space telecommunication area. But standard recommendation of CCSDS is not restrictive, so, we can select an appropriate encryption protocol among the layer. For synchronization, encryption sync is attached in the beginning of the encrypted data. In the exceptional environmental condition, although the receiver can not decrypt the normal data, the sender have no conception of that situation. In this paper, we propose a two-stage SES alarmed link encryption synchronization method having optimized threshold value necessary to decide whether the receiver has a correct decryption or not. first, through the experiment of mutual relations between error rate and encryption synchronization detection error, we can predict worst communication environment for the selected encryption synchronization pattern. second, through the experiment for finding what number of consecutive frame synchronization error is an appropriate reference value and analysis of that experiment, we suggest an optimized threshold value for resynchronization request. lastly, through the output images we can predict the probability error that should be guaranteed by channel coder.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.8
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• pp.1597-1605
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• 2015

Password authenticated key exchange (PAKE) is a protocol that a client stores its password to a server, authenticates itself using its password and shares a session key with the server. In multi-server PAKE, a client splits its password and stores them to several servers separately. Unless all the servers are compromised, client's password will not be disclosed in the multi-server setting. In attribute-based encryption (ABE), a sender encrypts a message M using a set of attributes and then a receiver decrypts it using the same set of attributes. In this paper, we introduce multi-server PAKE protocol that utilizes a set of attributes of ABE as a client's password. In the protocol, the client and servers do not need to create additional public/private key pairs because the password is used as a set of public keys. Also, the client and the servers exchange only one round-trip message per server. The protocol is secure against dictionary attacks. We prove our system is secure in a proposed threat model. Finally we show feasibility through evaluating the execution time of the protocol.