• Journal of Internet Computing and Services
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• v.10 no.6
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• pp.229-239
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• 2009

To solve user authentication problem, many remote user authentication schemes using password and smart card at the same time have been proposed. Due to the increasing of interest in personal privacy, there were some recent researches to provide user anonymity. In 2004, Das et al. firstly proposed an authentication scheme that guarantees user anonymity using a dynamic ID. In 2005, Chien et al. pointed out that Das et al.'s scheme has a vulnerability for guaranteing user anonymity and proposed an improved scheme. However their authentication scheme was found some weaknesses about insider attack, DoS attack, and restricted replay attack. In this paper, we propose an enhanced scheme which can remove vulnerabilities of Chien et al.'s scheme. The proposed authentication protocol prevented insider attack by using user's Nonce value and removed the restricted replay attack by replacing time stamp with random number. Furthermore, we improved computational efficiency by eliminating the exponentiation operation.

• KIPS Transactions on Computer and Communication Systems
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• v.2 no.12
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• pp.517-524
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• 2013

Although password-based authentication as known as knowledge-based authentication was commonly used but intrinsic problems such as dictionary attack remain unsolved. For that the study on possession-based authentication was required. User remote authentication using smartcard is proceeding actively since Lee et al. proposed user remote authentication using knowledge-based information(password) and possession-base information(smartcard) in 2002. in 2009, Xu et al. proposed a new protocol preserving user anonymity and Shin et al. proposed enhanced scheme with analysis of its vulnerabilities on user anonymity and masquerading attack in 2012. In this paper, we analyze Shin et al. scheme on forward secrecy and insider attack and present novel user authentication based on elliptic curve cryptosystem which is secure against forward secrecy, insider attack, user anonymity and masquerading attack.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2002.11a
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• pp.266-269
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• 2002

As a simulation or replacement of analog money in cyber space, the e-cash was introduced by using cryptographic primitives. Since a perfect anonymity system causes some illegal activities, such as money laundering, blackmailing, and illegal purchase, a revocable electronic system was paid a great attention to control the anonymity. In general, Trust Third Party(TTP) is introduced to detect any dubious user and coin, namely user tracing and coin tracing. In this paper we propose a new revocable anonymity e-cash system, and verify the security requirement as well. In our scheme a user first withdraws the e-coin from bank by using blind signature, and then TTP verifies the bank's signature and records the tracing information.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.2
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• pp.388-395
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• 2009

Three-party authenticated key exchange protocol based on smartcards using XOR and hash function operation instead of the public key operation has been proposed in 2006. Recently, it is doing for research because of increasing interest in privacy. This paper pointed out that proposed three-party authenticated key exchange protocol in 2006 has some problems; it is user anonymity and slow wrong input detection, and then we proposed new one to overcome these problems.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.11C
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• pp.1023-1029
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• 2006

In this Paper, we present a novel authentication and key exchange(AKE) protocol for inter-NSP(provider) roaming in IEEE 802.16e networks. The proposed protocol allows performing both user and device authentication jointly by using two different authentication credentials and Provides user anonymity and session key establishment. Also, this protocol requires only two round number message exchange between foreign network and home network.

• International Journal of Internet, Broadcasting and Communication
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• v.13 no.2
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• pp.67-75
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• 2021

As pass the three revised bills, the Personal Information Protection Act was revised to have a larger application for personal information. For an industrial development through an efficient and secure usage of personal information, there is a need to revise the existing anonymity processing method. This paper modifies the Zero Knowledge Proofs algorithm among the anonymity processing methods to modify the anonymity process calculations by taking into account the reliability of the used service company. More detail, the formula of ZKP (Zero Knowledge Proof) used by ZK-SNAKE is used to modify the personal information for pseudonymization processing. The core function of the proposed algorithm is the addition of user variables and adjustment of the difficulty level according to the reliability of the data user organization and the scope of use. Through Setup_p, the additional variable γ can be selectively applied according to the reliability of the user institution, and the degree of agreement of Witness is adjusted according to the reliability of the institution entered through Prove_p. The difficulty of the verification process is adjusted by considering the reliability of the institution entered through Verify_p. SimProve, a simulator, also refers to the scope of use and the reliability of the input authority. With this suggestion, it is possible to increase reliability and security of anonymity processing and distribution of personal information.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.12C
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• pp.1021-1028
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• 2008

In a network environment, when a user requests a server's service, a remote user authentication system using smart cards is a very practical solution to validate the eligibility of a user and provide secure communication. In these authentication schemes, due to fast progress of networks and information technology, most of provided services are in multi-server environments. However, there are no studies in multi-server authentication schemes using smart cards providing mutual anonymity so far. In this paper, we propose a novel user authentication scheme using smart cards providing mutual authentication and mutual anonymity for multi-server environments. Our proposed scheme achieves the low-computation requirement for smart cards and a user can use permitted various services in eligible servers by only one registration. Also, this scheme guarantees perfect mutual anonymity of participants.

• International Journal of Computer Science & Network Security
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• v.24 no.4
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• pp.155-162
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• 2024

Anonymity online has been an ever so fundamental topic among journalists, experts, cybersecurity professionals, corporate whistleblowers. Highest degree of anonymity online can be obtained by mimicking a normal everyday user of the internet. Without raising any flags of suspicion and perfectly merging with the masses of public users. Online Security is a very diverse topic, with new exploits, malwares, ransomwares, zero-day attacks, breaches occurring every day, staying updated with the latest security measures against them is quite expensive and resource intensive. Network security through anonymity focuses on being unidentifiable by disguising or blending into the public to become invisible to the targeted attacks. By following strict digital discipline, we can avoid all the malicious attacks as a whole. In this paper we have demonstrated a proof of concept and feasibility of securing yourself on a network by being anonymous.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.6C
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• pp.645-650
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• 2006

GSM(Global System for Mobile communications) provides mobile users with portability and convenience as the most popular standard for mobile phones in the world. However, GSM system has the problem that can't normally authenticate a user by the exposure of IMSI(International Mobile Subscriber Identity) of Ms(Mobile station) during the user authentication procedure. In this paper, we propose secure user authentication by preventing the exposure if IMSI via transfer the encrypted IMSI from the HLR(Home Location Register) and making the only network entities verified from the HLR use the IMSI value, as the modified mechanism based on the original user authentication protocol to solve this authentication problem. Also the proposed mechanism provides fast user authentication without changing the architecture between new VLR and old VLR in the original GSM user authentication protocol as well as user's anonymity by using a temporary ID.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.18 no.5
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• pp.31-39
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• 2008

Recently, remote user authentication schemes using smart cards has been researched to provide user privacy because of increasing interest and demands. Previously, provided authentication schemes were only concerned about providing user privacy against outside attackers, but the scheme. which guarantees user privacy against both a remote server and outside attackers, has been recently demanded because the user's information has leaked out through the service providers. When the remote server perceives a user doing a malicious act, the server should be able to trace the malicious user by receiving help from a trust agency. In this paper, we suggest a scheme which not only guarantees user privacy against both a remote server and outside attackers, but also provides traceable anonymity authentication.