• Journal of information and communication convergence engineering
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• v.22 no.2
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• pp.121-126
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• 2024

In enterprise environments, file owners are often required to share critical files with other users, with encryption-based file delivery systems used to maintain confidentiality. However, important information might be leaked if the cryptokey used for encryption is exposed. To recover confidentiality, the file owner must then re-encrypt and redistribute the file along with its new encryption key, which requires considerable resources. To address this, we propose a key management server that minimizes the distribution of encryption keys when critical files are compromised, with unique encryption keys assigned for each registered user to access critical files. While providing the targeted functions, the server employs a level of system resources comparable to that of legacy digital rights management. Thus, when implemented in an enterprise environment, the proposed server minimizes cryptokey redistribution while maintaining accessibility to critical files in the event of an information breach.

• Journal of Korea Society of Digital Industry and Information Management
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• v.13 no.4
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• pp.13-23
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• 2017

In order to protect personal information and important information (confidential information, sales information, user information, etc.) in the internal network, companies and organizations apply encryption to the Server-To-Server or Server-To-Client communication section, And are experiencing difficulties due to the increasing number of known attacks and intelligent security attacks. In order to apply the existing S / W encryption technology, it is necessary to modify the application. In the financial sector, "Comprehensive Measures to Prevent the Recurrence of Personal Information Leakage in the Domestic Financial Sector" has been issued, and standard guidelines for financial computing security have been laid out, and it is required to expand the whole area of encryption to the internal network. In addition, even in environments such as U-Health and Smart Grid, which are based on the Internet of Things (IoT) environment, which is increasingly used, security requirements for each collection gateway and secure transmission of the transmitted and received data The requirements of the secure channel for the use of the standard are specified in the standard. Therefore, in this paper, we propose a secure encryption algorithm through mutual authentication and grouping for each node through H / W based Network Control Server (NCS) applicable to internal system and IoT environment provided by enterprises and organizations. We propose a protocol design that can set the channel.

• Journal of Korea Multimedia Society
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• v.7 no.12
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• pp.1719-1728
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• 2004

The fusion of Internet technology and applications with wireless communication provides a new business model and promises to extend the possibilities of commerce to what is popularly called mobile commerce, or m-commerce. In mobile Internet banking service through wireless local area network, security is a most important factor to consider. We describe the development of security service for mobile Internet banking on Personal Digital Assistants (PDAs). Banking Server and Authentication Server were developed to simulate banking business and to support certificate management of authorized clients, respectively. To increase security, we took hybrid approach in implementation: symmetric block encryption and public-key encryption. Hash function and random number generation were exploited to generate a secret key. The data regarding banking service were encrypted with symmetric block encryption, RC4, and the random number sequence was done with public-key encryption. PDAs communicate through IEEE 802.IIb wireless LAN (Local Area Network) to access banking service. Several banking services and graphic user interfaces, which emulatedthe services of real bank, were developed to verity the working of each security service in PDA, the Banking Server, and the Authentication Server.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.4B
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• pp.288-299
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• 2012

To ensure data confidentiality and fine-grained access control in business environment, system model using KP-ABE(Key Policy-Attribute Based Encryption) and PRE(Proxy Re-Encryption) has been proposed recently. However, in previous study, data confidentiality has been effected by decryption right concentrated on cloud server. Also, Yu's work does not consider a access privilege management, so existing work become dangerous to collusion attack between malicious user and cloud server. To resolve this problem, we propose secure system model against collusion attack through dividing data file into header which is sent to privilege manager group and body which is sent to cloud server and prevent modification attack for proxy re-encryption key using d Secret Sharing, We construct protocol model in medical environment.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.10
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• pp.4198-4213
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• 2020

Data encryption, particularly application-level data encryption, is a common solution to protect data confidentiality and deal with security threats. Application-level encryption is a process in which data is encrypted before being sent to the database. However, cryptography transforms data and makes the query difficult to execute. Various studies have been carried out to find ways in order to implement a searchable encrypted database. In the current paper, we provide a new encrypting method and querying on encrypted data (ZSDB) for different data types. It is worth mentioning that the proposed method is based on secret sharing. ZSDB provides data confidentiality by dividing sensitive data into two parts and using the additional server as Dictionary Server. In addition, it supports required operations on various types of data, especially LIKE operator functioning on string data type. ZSDB dedicates the largest volume of execution tasks on queries to the server. Therefore, the data owner only needs to encrypt and decrypt data.

• International journal of advanced smart convergence
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• v.5 no.4
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• pp.26-31
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• 2016

In a cloud computing environment, a cryptographic service allows an information owner to encrypt the information and send it to a cloud server as well as to receive and decode encrypted data from the server which guarantees the confidentiality of shared information. However, if an attacker gains a coded data and has access to an encryption key via cloud server, then the server will be unable to prevent data leaks by a cloud service provider. In this paper, we proposed a key management server which does not allow an attacker to access to a coded key of the owners and prevents data leaks by a cloud service provider. A key management server provides a service where a server receives a coded public key of an information user from an owner and delivers a coded key to a user. Using a key management server proposed in this paper, we validated that the server can secure the confidentiality of an encryption key of data owners and efficiently distribute keys to data users.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.12
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• pp.4508-4530
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• 2021

Today distributed data storage service are being widely used. However lack of proper means of security makes the user data vulnerable. In this work, we propose a Randomized Block Size (RBS) model for secure data storage in distributed environments. The model work with multifold block sizes encrypted with the Chinese Remainder Theorem-based RSA (C-RSA) technique for end-to-end security of multimedia data. The proposed RBS model has a key generation phase (KGP) for constructing asymmetric keys, and a rand generation phase (RGP) for applying optimal asymmetric encryption padding (OAEP) to the original message. The experimental results obtained with text and image files show that the post encryption file size is not much affected, and data is efficiently encrypted while storing at the distributed storage server (DSS). The parameters such as ciphertext size, encryption time, and throughput have been considered for performance evaluation, whereas statistical analysis like similarity measurement, correlation coefficient, histogram, and entropy analysis uses to check image pixels deviation. The number of pixels change rate (NPCR) and unified averaged changed intensity (UACI) were used to check the strength of the proposed encryption technique. The proposed model is robust with high resilience against eavesdropping, insider attack, and chosen-plaintext attack.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.19 no.2
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• pp.31-38
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• 2009

To provide the privacy of a keyword, a public key encryption with keyword search(PEKS) firstly was propsed by Boneh et al. The PEKS scheme enables that an email sender sends an encrypted email with receiver's public key to an email server and a server can obtain the relation between the given encrypted email and an encrypted query generated by a receiver. In this email system, we easily consider the situation that a user sends the one identical encrypted email to multi-receiver like as group e-mail. Hwang and Lee proposed a searchable public key encryption considering multi-receivers. To reduce the size of transmission data and the server's computation is important issue in multi-receiver setting. In this paper, we propose an efficient searchable public key encryption for multi-receiver (mPEKS) which is more efficient and reduces the server's pairing computation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.2
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• pp.344-352
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• 2006

We developed the facsimile encryption system that could send/receive the cipher text and plain text automatically. This facsimile encryption system is adopting the 128bits SEED encryption algorithm, 1024bits modular and 256bits exponential Diffie-Hellman key exchange method. We can reduce the cipher text transmitting time by developing the Dual Facsimile Server, it can make the real time encryption communication. Key is safely exchanged by the exchanging the listed serial numbers when the Diffie-Hellman key exchanging.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.6
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• pp.931-936
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• 2002

By emphasize and enhance security in encryption of same viewdata in this research, constructed video conference system that apply real time video encryption techniques that confidentiality and integrity aspect are emphasized than video conference system that depend on existent user certification techniques. Sender's image transmits Vernam's encryption process to listener by packet. Listener can display image through image's decipher process and uncompress after unite receiving transmited image. This time, solved transmission speed delay problem by video's real time encryption using Vernam's algorithm that encryption and the decipher speed are fast. Simplification problem of Vernam algorithm wished to solve Session Key that use security Key that is used encipherment and decipher in channel between Client and Server using RSA algorithm.