University of Oulu

Hong Tran, N., Nguyen, T., Binh Nguyen, Q., Pirttikangas, S., & Kechadi, M.-T. (2021). Crystal: A privacy-preserving distributed reputation management. In D. C. Wyld, & D. Nagamalai (Eds.), Natural Language Processing. Computer Science & Information Technology 159, 295–308.

Crystal : a privacy-preserving distributed reputation management

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Author: Hong Tran, Ngoc1; Nguyen, Tri2; Binh Nguyen, Quoc3;
Organizations: 1Vietnamese-German University, Vietnam
2Center for Ubiquitous Computing, University of Oulu, Finland
3Ton Duc Thang University, Vietnam
4School of Computer Science, University College Dublin, Ireland
5Insight Centre for Data Analytics, University College Dublin
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 1.5 MB)
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Language: English
Published: AIRCC Publishing, 2021
Publish Date: 2022-10-26


This paper investigates the situation in which exists the unshared Internet in specific areas while users in there need instant advice from others nearby. Hence, a peer-to-peer network is necessary and established by connecting all neighbouring mobile devices so that they can exchange questions and recommendations. However, not all received recommendations are reliable as users may be unknown to each other. Therefore, the trustworthiness of advice is evaluated based on the advisor’s reputation score. The reputation score is locally stored in the user’s mobile device. It is not completely guaranteed that the reputation score is trustful if its owner uses it for a wrong intention. In addition, another privacy problem is about honestly auditing the reputation score on the advising user by the questioning user. Therefore, this work proposes a security model, namely Crystal, for securely managing distributed reputation scores and for preserving user privacy. Crystal ensures that the reputation score can be verified, computed and audited in a secret way. Another significant point is that the device in the peer-to-peer network has limits in physical resources such as bandwidth, power and memory. For this issue, Crystal applies lightweight Elliptic Curve Cryptographic algorithms so that Crystal consumes less the physical resources of devices. The experimental results prove that our proposed model performance is promising.

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Series: Computer science and information technology
ISSN: 2231-5403
ISSN-E: 2231-5403
ISSN-L: 2231-5403
ISBN Print: 978-1-925953-57-2
Volume: 11
Issue: 23
Pages: 295 - 308
Article number: 23
DOI: 10.5121/csit.2021.112323
Host publication: Natural language processing
Host publication editor: Wyld, David C.
Nagamalai, Dhinaharan
Conference: International Conference on Networks & IOT
Type of Publication: A4 Article in conference proceedings
Field of Science: 113 Computer and information sciences
Funding: This work is partially supported by TrustedMaaS project - the Infotech institute of the University of Oulu, Science, and Academy of Finland 6Genesis Flagship (Grant 318927).
Academy of Finland Grant Number: 318927
Detailed Information: 318927 (Academy of Finland Funding decision)
Copyright information: © 2021 By AIRCC Publishing Corporation. This article is published under the Creative Commons Attribution (CC BY) license.