• Smart Media Journal
• /
• v.12 no.9
• /
• pp.95-102
• /
• 2023

As the utilization value of personal information increases, discussions on how to provide personal information are active, but information required by institutions to utilize personal information is being exposed more than necessary. Therefore, personal privacy protection is essential to overcome the problems and limitations of personal information protection. In this study, a decentralized identity information management model that overcomes the problems and limitations of the centralized identity management method of personal information and manages and selectively provides personal information by the information owner himself and demonstrates the excellence of personal information by implementing the Smart Personal Information Provision System (SPIPS) in the PBFT consensus algorithm through experiments.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.18 no.3
• /
• pp.720-737
• /
• 2024

Private set intersection cardinality (PSI-CA) is a typical problem in the field of secure multi-party computation, which enables two parties calculate the cardinality of intersection securely without revealing any information about their sets. And it is suitable for private data protection scenarios where only the cardinality of the set intersection needs to be calculated. However, most of the currently available PSI-CA protocols only meet the security under the semi-honest model and can't resist the malicious behaviors of participants. To solve the problems above, by the application of the variant of Elgamal cryptography and Bloom filter, we propose an efficient PSI-CA protocol with high security. We also present two new operations on Bloom filter called IBF and BIBF, which could further enhance the safety of private data. Using zero-knowledge proof to ensure the safety under malicious adversary model. Moreover, in order to minimize the error in the results caused by the false positive problem, we use Garbled Bloom Filter and key-value pair packing creatively and present an improved PSI-CA protocol. Through experimental comparison with several existing representative protocols, our protocol runs with linear time complexity and more excellent characters, which is more suitable for practical application scenarios.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.14 no.1
• /
• pp.245-251
• /
• 2014

Mix network plays a key role in electronic voting to preserve anonymity and lots of mixnet schemes have been proposed so far. However, they requires complex and costly zero-knowledge proofs to provide their correct mixing operations. In 2010, Seb$\acute{e}$ et al. proposed an efficient and lightweight mixnet scheme based on a cryptographic secure hash function instead of zero-knowledge proofs. In this paper, we present a more efficient and faster mixnet scheme than Seb$\acute{e}$ et al.'s scheme under the same assumption. Also, our scheme is secure.

• Journal of Advanced Navigation Technology
• /
• v.14 no.5
• /
• pp.691-696
• /
• 2010

The main idea is to protect the signer of a document against the document being digitally distributed without the cooperation of signer. This paper proposes a new scheme of undeniable signature, which is so effective and improved D. Chaum's scheme. And our scheme which is zero-knowledge proved by using one-way function and partition - selection method, shows that its communication(challenge-response) only needs much fewer times during the confirmation protocol and disavowal protocol respectively, being very useful for wireless network environment. In the meantime our scheme allows the verifier to verify that the signature is valid, while the signer doesn't know the original message and the signature, to preserve the privacy of the verifier.

• Journal of the Korea Society of Computer and Information
• /
• v.28 no.7
• /
• pp.77-84
• /
• 2023

This research originated from the need to enhance the security of secure multiparty computation by ensuring that participants involved in multiparty computations provide truthful inputs that have not been manipulated. While malicious participants can be involved, which goes beyond the traditional security models, malicious behaviors through input manipulation often occur in real-world scenarios, leading to privacy infringements or situations where the accuracy of multiparty computation results cannot be guaranteed. Therefore, in this study, we propose a signature scheme applicable to secure multiparty technologies, combining it with secret sharing to strengthen the accuracy of inputs using authentication techniques. We also investigate methods to enhance the efficiency of authentication through the use of batch authentication techniques. To this end, a scheme capable of input certification was designed by applying a commitment scheme and zero-knowledge proof of knowledge to the CL signature scheme, which is a lightweight signature scheme, and batch verification was applied to improve efficiency during authentication.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
• /
• 1994.11a
• /
• pp.29-31
• /
• 1994

In digital signature schemes derived from the zero-knowledge proof techniques, some authors often claims that the length of hash-values for their schemes could be as short as 64 or 72 bits for the security level of 2$^{-64}$ or 2$^{-72}$ . This letter shows that signature schemes with such short hash values cannot achieve the security levels as stated, due to the birthday attack by the signer.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.30 no.6
• /
• pp.999-1012
• /
• 2020

As the utilize of personal health records increases in recent years, research on cryptographic protocol for protecting personal information of personal health records has been actively conducted. Currently, personal health records are commonly encrypted and outsourced to the cloud. However, this method is limited in verifying the integrity of personal health records, and there is a problem with poor data availability because it is essential to use it in decryption. To solve this problem, this paper proposes a verifiable cloud-based personal health record management scheme using Redactable signature scheme and zero-knowledge proof. Verifiable cloud-based personal health record management scheme can be used to verify the integrity of the original document while preserving privacy by deleting sensitive information by using Redactable signature scheme, and to verify that the redacted document has not been deleted or modified except for the deleted part of the original document by using the zero-knowledge proof. In addition, it is designed to increase the availability of data than the existing management schemes by designing to recover deleted parts only when necessary through the Redact Recovery Authority. And we propose a verifiable cloud-based personal health record management model using the proposed scheme, and analysed its efficiency by implementing the proposed scheme.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
• /
• 1992.11a
• /
• pp.165-179
• /
• 1992

영지식 대화증명은 인증자(prover)가 비밀정보를 노출시키지 않으면서, 검증자(verifier)와 대화를 통해서 이 비밀정보를 알고 있음을 검증자에게 증명하는 방법이다. 본 논문에서는 ElGamal 암호 알고리듬을 이용하여 메세지 전송과 개인 인중이 동시에 가능한 순방향 영지식 증명 프로토콜과 역방향 영지식 증명 프로토콜을 제안한다. 그리고 전송효율을 송신한 전비트와 정보비트와의 비로 정의하여 각각의 프로토콜의 전송효율을 계산한다.

• Proceedings of the Korean Society of Computer Information Conference
• /
• 2023.07a
• /
• pp.567-568
• /
• 2023

본 논문에서는 블록체인 기반 DID기술을 이용하여 원격교육에서 발생하는 학습데이터를 효율적으로 관리하기 위한 방법으로, 학습데이터 가중치를 고려한 DID 메타데이터관리방법을 제안하였다. 메타데이터의 식별자에 대하여 특정위치로 데이터 가중치를 검색하도록 하고 해당 가중치에 따라 처리방법을 다양화 할 수 있다. 본문에서는 블록체인의 Zero Knowledge Proof 방식 처리에 차별화를 두어 메타데이터를 처리하였으며 데이터 처리속도 및 데이터관리에 효율성높일 수 있다.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.18 no.1
• /
• pp.150-156
• /
• 1993

This paper studies an Authentication sheme which is used polynomial equation over GF(2n)for reducing time to authenticate sender and his message in secret data communication. Also in order to maintain strong secrecy, this scheme use interactive Zero-knowledge proof protocol for generating information of sender's authentication via unprotected communication channel.