• Journal of Korea Multimedia Society
• /
• v.6 no.2
• /
• pp.288-300
• /
• 2003

As the importance of information security gets recognized seriously, ciphers technology gets used more. Particularly, since public key ciphers are easier to control the key than symmetric key ciphers and also digital signature is easily implemented, public key ciphers are increased used. Nowadays, public key infrastructure is established and operated to use efficiently and securely the public key ciphers. In the public key infrastructure, the user registers at the certificate authority to generate the private key and public key pair and the certificate authority issues the certificate on the public key generated. Through this certificate, key establishment between users is implemented and encryption communication becomes possible. But, control function of session key established in the public key infrastructure is not provided. In this thesis, the certificate issuing protocol to support the key recovery of the session key established during the wireless authentication and key establishment is proposed.

• Journal of Aerospace System Engineering
• /
• v.6 no.1
• /
• pp.19-25
• /
• 2012

Nowadays, the demand of civil application of an UAV has been being increased all over the world. And many projects are going on to develop a new regulatory system for an UAV to access a national airspace. Especially, to fly UAV over the non-restricted airspace as a standard airworthiness standard, many authority funded research institutes and associations are studying regulatory environment. For the UAV to access civil airspace, the certification system of the aviation regulation have to allow this. FAA of US, CASA of Australia and European authorities are now issuing an experimental airworthiness certificate to a civil UAV. This is the first step of issuing a standard airworthiness certificate. And many people believe that civil UAV can fly over a NAS if some technical issues are resolved. In this study, I would like to present an international trends of a civil UAV regulation system, reliability trend of unmanned aerial system and would like to bring up a our regulatory environment and suggest an UAV regulatory policy.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2016.10a
• /
• pp.762-764
• /
• 2016

The ECQV(Elliptic Curve Qu-Vanstone) is a implicit certificate scheme based on ECC(Elliptic Curve Cryptography). Implicit certificates are smaller and faster than a traditional explicit certificate. Therefore, it can be used in a memory or bandwidth constraint communication environments. Also, the butterfly key expansion algorithm is a method to issue many certificates by using only one public key. In this study, by applying the butterfly key expansion algorithm to ECQV, we suggest a new useful issuing certificate method that can be used in vehicular communication environments.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
• /
• 2002.11a
• /
• pp.153-156
• /
• 2002

실생활에서 권한의 위임을 통한 대리서명은 일상적으로 널리 사용되고 있다. 이러한 대리서명을 온라인상에서 사용하기 위해서는 위임자의 권한위임장이 안전하게 유통되어야 하고 대리자의 권한 오남용을 막아야 한다. 이에 따라 IETF의 PKIX 워킹그룹에서는 위임인증서(proxy certificate)를 제안하였다. 본 논문에서는 대리자의 권한의 오남용을 막기위해 위임제한 필드를 제안하였고, 위임 인증서의 서비스 가능성을 보이기 위한 프로토타입을 설계하고 구현하였다.

• Proceedings of the KIEE Conference
• /
• 2001.04a
• /
• pp.433-435
• /
• 2001

Certification is the process of issuing a certificate to indicate conformance with a standard, a set of guidelines or some similar document. Any organization or individual may issue a certificate. In some cases a certificate may be required for legal reason. In such circumstance the certificate takes on the role of a licence from a statutory authority. In railway industry safety has always been the first concern. To achieve certification, specific safety management is required. In this paper, different types of safety management process through out the world are mentioned, and safety management structure appropriate to our circumstance is represented.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.17 no.3
• /
• pp.55-67
• /
• 2007

In ad hoc network, especially in the environment which the system authority only exists at the beginning of the network, it is very important problem how to issue the certificates in self-initialized public key scheme that a node generates its certificate with public and private key pair and is signed that by the system authority. In order to solve this problem, early works present some suggestions; remove the system authority itself and use certificate chain, or make nodes as system authorities for other nodes' certificates. In this paper, we suggest another solution, which can solve many problem still in those suggestions, using proxy signature and threshold signature, and prove its performance using simulation and analyse its security strength in many aspects.

• International Commerce and Information Review
• /
• v.10 no.1
• /
• pp.155-174
• /
• 2008

This study wished to inspect about certificate of origin issuance authorities subject in certificate of origin issuance mode by spread of FTA, and investigate about improvement plan of current certificate of origin issuance authorities choice for smoothness trade business our country in FTA age to be expanded gradually. Fundamental purpose and meaning of FTA strengthen industry competitive power of two countries because expand trade and investment between the agreement conclusion country, and is expected to esteem agreement target department's estimation at FTA certificate of origin issuance subject choice because is meaning that strengthen trade competitive power, and raise trade company's convenience. Therefore, our country FTA representative authorities is recognized authoritativeness and stability from trade company and trade connection authorities, and is suitable in legal application or institution that can propel with consistency about policy propelled hereafter has to be chosen, FTA agreement country is representative authorities that recognize, and to issue from customs services which is a government agency which can progress business is place of origin issuance business and the place of origin examination, is expected to become more and more effective.

• Journal of Internet Computing and Services
• /
• v.9 no.4
• /
• pp.69-77
• /
• 2008

I propose adding users’Media Access Control (MAC) addresses to standard X.509 certificates to provide more secure authentication. The MAC address can be added by the issuing Certification Authority (CA) to the "extensions" section of the X.509 certificate. I demonstrate that when two users with MAC address information on their digital certificates communicate, the MAC address on the first user’s certificate can be easily verified by the second user. In this way, security can be improved without markedly degrading system performance and the level of initial trust between participants in virtual communities will be improved.

• International Journal of Computer Science & Network Security
• /
• v.23 no.5
• /
• pp.13-20
• /
• 2023

In connected vehicles, drivers are exposed to attacks when they communicate with unauthenticated peers. This occurs when a vehicle relies on outdated information resulting in interactions with vehicles that have expired or revoked certificates claiming to be legitimate nodes. Vehicles must frequently receive or query an updated revoked certificate list to avoid communicating with suspicious vehicles to protect themselves. In this paper, we propose a scheme that works on a highway divided into clusters and managed by roadside units (RSUs) to ensure authenticity and preserve hidden identities of vehicles. The proposed scheme includes four main components each of which plays a major role. In the top hierarchy, we have the authority that is responsible for issuing long-term certificates and managing and controlling all descending intermediate authorities, which cover specific regions (e.g., RSUs) and provide vehicles with short-term pseudonyms certificates to hide their identity and avoid traceability. Every certificate-related operation is recorded in a blockchain storage to ensure integrity and transparency. To regulate communication among nodes, security managers were introduced to enable authorization and access right during communications. Together, these components provide vehicles with an immediately revoked certificate list through RSUs, which are provided with publish/subscribe brokers that enable a controlled messaging infrastructure. We validate our work in a simulated smart highway environment comprising interconnected RSUs to demonstrate our technique's effectiveness.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.28 no.4
• /
• pp.987-997
• /
• 2018

Blockchain has tamper-free, so many applications are developing to leverage tamper-free features of blockchain. MIT Media Labs proposed BlockCerts, educational certificate blockchain System, to solve problems of legacy certificate verifications. Existing educational certificate blockchain Systems are based on public blockchain such as bitcoin, Ethereum, so any entity can participate educational institute in principal. Moreover, the exisitng educational certricate blockchain system utilizes the integrity of blockchain, but the confidentiality of the educational certificate is not provided. This paper propose a digital certificate system based on private blockchain, name HyperCerts. Therefore, only trusted entity can participate in the private blockchain network, Hyperledger, as the issuer of digital certificate. Furthermore, the practical byzantine fault tolerance is used as consensus algorithm, HyperCerts reduce dramatically the latency of issuing digital certificate and required computing power. HyperCerts stores the hash value of digital certificate into the ledger, so breach of personal information by malicious entity in the private blockchain is protected.