• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제12권10호
• /
• pp.5100-5119
• /
• 2018

Most of existing privacy-preserving multi-authorities attribute-based encryption schemes (PP-MA-ABE) only considers the privacy of the user identity (ID). However, in many occasions information leakage is caused by the disclosing of his/her some sensitive attributes. In this paper, we propose a collusion-resisting ciphertext-policy PP-MA-ABE (CRPP-MACP-ABE) scheme with hiding both user's ID and attributes in the cloud storage system. We present a method to depict anonymous users and introduce a managerial role denoted by IDM for the management of user's anonymous identity certificate ($AID_{Cred}$). The scheme uses $AID_{Cred}$ to realize privacy-preserving of the user, namely, by verifying which attribute authorities (AAs) obtain the blinded public attribute keys, pseudonyms involved in the $AID_{Cred}$ and then distributes corresponding private keys for the user. We use different pseudonyms of the user to resist the collusion attack launched by viciousAAs. In addition, we utilize IDM to cooperate with multiple authorities in producing consistent private key for the user to avoid the collusion attack launched by vicious users. The proposed CRPP-MACP-ABE scheme is proved secure. Some computation and communication costs in our scheme are finished in preparation phase (i.e. user registration). Compared with the existing schemes, our scheme is more efficient.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제11권4호
• /
• pp.2254-2275
• /
• 2017

In this paper, we present an IND-CCA2 secure certificateless proxy re-encryption scheme in the random oracle model. A certificateless public key cryptography simplifies the certificate management in a traditional public key infrastructure and the built-in key escrow feature in an identity-based public key cryptography. Our scheme shares the merits of certificateless public key encryption cryptosystems and proxy re-encryption cryptosystems. Our certificateless proxy re-encryption scheme has several practical and useful properties - namely, multi-use, unidirectionality, non-interactivity, non-transitivity and so on. The security of our scheme bases on the standard bilinear Diffie-Hellman and the decisional Bilinear Diffie-Hellman assumptions.

• ETRI Journal
• /
• 제38권4호
• /
• pp.724-734
• /
• 2016

To achieve confidentiality, integrity, authentication, and non-repudiation simultaneously, the concept of signcryption was introduced by combining encryption and a signature in a single scheme. Certificate-based encryption schemes are designed to resolve the key escrow problem of identity-based encryption, as well as to simplify the certificate management problem in traditional public key cryptosystems. In this paper, we propose a new certificate-based signcryption scheme that has been proved to be secure against adaptive chosen ciphertext attacks and existentially unforgeable against chosen-message attacks in the random oracle model. Our scheme is not based on pairing and thus is efficient and practical. Furthermore, it allows a signcrypted message to be immediately verified by the public key of the sender. This means that verification and decryption of the signcrypted message are decoupled. To the best of our knowledge, this is the first signcryption scheme without pairing to have this feature.

• 한국멀티미디어학회논문지
• /
• 제14권6호
• /
• pp.775-784
• /
• 2011

본 논문에서는 신원기반 다중수신자 암호 기법의 장점인 묵시적 인증을 제공하는 동시에 키 위탁문제를 해결하기 위한 무인증서 공개키 암호 기술 기반의 새로운 다중수신자 암호 기법을 소개한다. 제안 기법은 다중수신자에 대한 메시지 암호화 단계에서 겹선형 페어링 연산을 제거하였을 뿐만 아니라 복호화 단계에서 단 한 번의 겹선형 페어링 연산만을 요구하는 매우 효율적인 다중수신자 암호 기법이다. 또한, 본 논문에서는 제안 기법을 이용하여 스테이트리스 수신자 환경을 위한 서브셋-커버 프레임워크 기반의 새로운 공개키 브로드캐스트 암호 기법을 제시한다.

• 대한수학회보
• /
• 제46권4호
• /
• pp.743-769
• /
• 2009

An ID-based DNF signature scheme is an ID-based signature scheme with an access structure which is expressed as a disjunctive normal form (DNF) with literals of signer identities. ID-based DNF signature schemes are useful to achieve not only signer-privacy but also a multi-user access control. In this paper, we formally define a notion of a (non-interactive) ID-based DNF signature and propose the first noninteractive ID-based DNF signature schemes that are secure under the computational Diffie-Hellman and subgroup decision assumptions. Our first scheme uses random oracles, and our second one is designed without random oracles. To construct the second one, we use a novel technique that converts a non-interactive witness indistinguishable proof system of encryption of one bit into a corresponding proof system of encryption of a bit-string. This technique may be of independent interest. The second scheme straightforwardly yields the first ID-based ring signature that achieves anonymity against full key exposure without random oracles. We finally present two extensions of the proposed ID-based DNF signature schemes to support multiple KGCs and different messages.

• International Journal of Computer Science & Network Security
• /
• 제24권4호
• /
• pp.11-25
• /
• 2024

The proliferation of IoT devices has presented an unprecedented challenge in managing device identities securely and efficiently. In this paper, we introduce an innovative Hybrid Blockchain-Based Approach for IoT Identity Management that prioritizes both security and efficiency. Our hybrid solution, strategically combines the advantages of direct and indirect connections, yielding exceptional performance. This approach delivers reduced latency, optimized network utilization, and energy efficiency by leveraging local cluster interactions for routine tasks while resorting to indirect blockchain connections for critical processes. This paper presents a comprehensive solution to the complex challenges associated with IoT identity management. Our Hybrid Blockchain-Based Approach sets a new benchmark for secure and efficient identity management within IoT ecosystems, arising from the synergy between direct and indirect connections. This serves as a foundational framework for future endeavors, including optimization strategies, scalability enhancements, and the integration of advanced encryption methodologies. In conclusion, this paper underscores the importance of tailored strategies in shaping the future of IoT identity management through innovative blockchain integration.

• 한국멀티미디어학회논문지
• /
• 제16권10호
• /
• pp.1156-1162
• /
• 2013

Face verification has been widely studied during the past two decades. One of the challenges is the rising concern about the security and privacy of the template database. In this paper, we propose a secure face verification system which generates a unique secure cryptographic key from a face template. The face images are processed to produce face templates or codes to be utilized for the encryption and decryption tasks. The result identity data is encrypted using Advanced Encryption Standard (AES). Distance metric naming hamming distance and Euclidean distance are used for template matching identification process, where template matching is a process used in pattern recognition. The proposed system is tested on the ORL, YALEs, and PKNU face databases, which contain 360, 135, and 54 training images respectively. We employ Principle Component Analysis (PCA) to determine the most discriminating features among face images. The experimental results showed that the proposed distance measure was one the promising best measures with respect to different characteristics of the biometric systems. Using the proposed method we needed to extract fewer images in order to achieve 100% cumulative recognition than using any other tested distance measure.

• 한국멀티미디어학회논문지
• /
• 제9권10호
• /
• pp.1304-1313
• /
• 2006

21세기를 맞이하면서 정보통신기술의 발전과 인터넷 이용 확산 등으로 사용자 인증이 중요한 문제로 대두되고 있으며, 보다 강력한 사용자 인증을 위하여 생체인식 기술의 연구가 활발히 진행되고 있다. 그러나 사용자 인증을 위한 생체정보가 타인에게 도용된다면 패스워드나 PIN과 달리 변경이 불가능하므로 심각한 문제를 일으킨다. 본 논문에서는 센서에서 획득된 지문영상을 클라이언트로 안전하게 전송하는 프로토콜을 제안한다. 특히, 계산능력이 부족한 임베디드 프로세스를 내장한 지문센서에서 지문영상을 실시간으로 암호화하기 위하여 지문영상 전체를 암호화하는 대신, 지문영상의 특정 비트 평면만을 암호화하는 부분암호화 알고리즘을 제안한다. 일반적인 부분암호화 방법에서 사용되어지는 최상위 비트 평면으로 부분암호화를 착 경우 간단한 공격으로 지문의 융선정보를 알 수 있기 때문에 지문인식 시스템에 공격이 가능한 문제점이 있다. 본 논문에서는 이러한 문제를 해결하기 위하여, 최상위 비트정보 대신 최하위 비트정보를 이용하는 개선된 선택적 비트 평면 암호화 방법을 사용하였다. 제안된 알고리즘의 성능을 분석하기 위해 16비트 임베디드 프로세서를 가진 지문센서를 개발하고 부분암호화 방법을 구현한 결과, 기밀성 보장 및 실시간 처리가 가능함을 확인하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제8권7호
• /
• pp.2554-2571
• /
• 2014

Certificate-based cryptography is a new cryptographic paradigm that provides an interesting balance between identity-based cryptography and traditional public key cryptography. It not only simplifies the complicated certificate management problem in traditional public key cryptography, but also eliminates the key escrow problem in identity-based cryptography. As an extension of the signcryption in certificate-based cryptography, certificate-based signcryption provides the functionalities of certificate-based encryption and certificate-based signature simultaneously. However, to the best of our knowledge, all constructions of certificate-based signcryption in the literature so far have to be based on the costly bilinear pairings. In this paper, we propose a certificate-based signcryption scheme that does not depend on the bilinear pairings. The proposed scheme is provably secure in the random oracle model. Due to avoiding the computationally-heavy paring operations, the proposed scheme significantly reduces the cost of computation and outperforms the previous certificate-based signcryption schemes.

• IEIE Transactions on Smart Processing and Computing
• /
• 제2권2호
• /
• pp.57-66
• /
• 2013

Wireless Sensor Networks consist of small, inexpensive, low-powered sensor nodes that communicate with each other. To achieve a low communication cost in a resource constrained network, a novel concept of signcryption has been applied for secure communication. Signcryption enables a user to perform a digital signature for providing authenticity and public key encryption for providing message confidentiality simultaneously in a single logical step with a lower cost than that of the sign-then-encrypt approach. Ring signcryption maintains the signer's privacy, which is lacking in normal signcryption schemes. Signcryption can provide confidentiality and authenticity without revealing the user's identity of the ring. This paper presents the security notions and an evaluation of an ID-based ring signcryption scheme for wireless sensor networks. The scheme has been proven to be better than the existing schemes. The proposed scheme was found to be secure against adaptive chosen ciphertext ring attacks (IND-IDRSC-CCA2) and secure against an existential forgery for adaptive chosen message attacks (EF-IDRSC-ACMA). The proposed scheme was found to be more efficient than scheme for Wireless Sensor Networks reported by Qi. et al. based on the running time and energy consumption.