Browsing by Author "Tseng, Fu-Kuo"

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A Privacy-Preserving Encoding for Efficient Comparison Queries and Access Control from Predicate Encryption
(2015-01-01)
Chen, Shao-Heng
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Tseng, Fu-Kuo
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Chen, Rong-Jaye
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交大名義發表
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National Chiao Tung University
A hidden vector encryption (HVE) scheme, one type of predicate encryption schemes, can support comparison predicates on encrypted keywords through encrypted predicates by pairing transformed keyword vectors with predicate vectors. However, the length of these vectors grows in proportion to the size of the keyword space and so does the system complexity. In this paper, we provide a privacy-preserving encoding for efficient comparison queries, where the length of the vectors and the system complexity is only logarithmically proportional to the size of the keyword space. In addition, our encoding integrates a HVE scheme and a ciphertext-policy attribute based encryption (CPABE) scheme. This integration provides not only the access control based on the searchable keywords but also balanced overheads among encryption, key generation and query for both computation and storage overheads.
A Secure Reed-Solomon Code Incentive Scheme for Commercial Ad Dissemination Over VANETs
(2011-11-01)
Tseng, Fu-Kuo
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Liu, Yung-Hsiang
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Hwu, Jing-Shyang
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Chen, Rong-Jaye
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資訊工程學系
A recent surge of research on vehicular ad hoc networks (VANETs) has given us new opportunities and challenges. Aside from safety-related applications, commercial applications also find their way to fully utilize these networks. One of the promising applications is the dissemination of commercial advertisements over VANETs. However, there are uncooperative vehicles that may disrupt the spreading of these advertisements. To encourage cooperation, we want to address proper incentives and security measurements. In this paper, we use Reed-Solomon codes (RS-codes) to construct our incentive scheme and enhance its security by introducing one discrete logarithm representation problem. Our construction yields a secure and practical commercial advertisement dissemination scheme over VANETs.
Cryptanalysis and Improvement of an Encoding Method for Private-Key Hidden Vector Encryptions
(2015-09-01)
Tseng, Fu-Kuo
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Chen, Rong-Jaye
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資訊工程學系
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Department of Computer Science
A predicate encryption scheme enables the owner of the master key to enforce fine-grained access control on encrypted cloud data through the delegation of predicate tokens to cloud storages. In particular, Blundo et al. proposed a construction where a predicate token reveals partial information of the involved keywords to enable efficient operations on encrypted keywords. However, we found that a predicate token reveals more information than what was claimed because of the encoding scheme. In this letter, we not only analyze this extra information leakage but also present an improved encoding scheme for the Blundo et al\'s scheme and the other similar schemes to preserve predicate privacy.
Ensuring Correctness of Range Searches on Encrypted Cloud Data
(2012)
Tseng, Fu-Kuo
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Liu, Yung-Hsiang
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Chen, Rong-Jaye
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資訊工程學系
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Department of Computer Science
We target at one newly introduced security concern which is not fully addressed when moving (encrypted) data to the cloud, namely, the security of the search results from the cloud. The cloud storage provider (CSP) might be compromised or simply act maliciously for their own good, which yields incorrect search results. In this paper, we exploit hidden vector encryption to tackle this important security problem. Our construction enables CSPs to provide a proof of the search results to be verified later by the cloud storage users. In particular, this proposed scheme handles equality and range searches on encrypted data. Users can verified the correctness of the search results without decrypting for the corresponding file contents. Any tampering with the search results by CSPs will be caught, while any incorrect charge against CSPs for tampering search results can be rectified. Finally, we present extensive security and performance analysis to show the security and practicality of our scheme.
Halo: A Hierarchical Identity-Based Public Key Infrastructure for Peer-to-Peer Opportunistic Collaboration
(2009)
Tseng, Fu-Kuo
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Zao, John K.
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Liu, Yung-Hsiang
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Kuo, Fang-Po
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資訊工程學系
The lack of information security protection for peer-to-peer systems has hampered the use of this robust and scalable technology in sensitive applications. The security weakness is rooted in the server-less architecture and the demand driven ad-hoc operation scenarios of peer-to-peer systems. Together, they prohibit scalable key management using traditional symmetric/asymmetric cryptographic techniques. The advent of hierarchical identity-based cryptography and thresholded/joint secret sharing offers a possible solution to this problem. In this paper, we present the design of Halo, a hierarchical identity-based public key infrastructure that uses these novel technologies to perform recursive instantiation of private key generators and establish a trust hierarchy with unlimited number of levels. The PKI thus enables the employment of hierarchical identity-based public key encryption, signature, and signcryption for the protection of peer-to-peer applications. The effort to implement a proof-of-concept prototype as a JXTA service module was also discussed.
iPEKS: Fast and Secure Cloud Data Retrieval from the Public-key Encryption with Keyword Search
(2013)
Tseng, Fu-Kuo
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Chen, Rong-Jaye
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Lin, Bao-Shuh Paul
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資訊工程學系
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Department of Computer Science
In recent years, considerable concern has arisen over the security of the data stored in the cloud. A number of studies have suggested the use of cryptographic primitives to protect the data. As these tools transform the data into an unintelligible form, secure and efficient retrieval of the encrypted data from the cloud becomes a major challenge. The public-key encryption with keyword search (PEKS) scheme and many of its variants have been proposed to respond to this challenge. However, given a large number of data (or searchable keywords) would be tested sequentially in these PEKS schemes, previous search results should be employed to improve the efficiency of future searches. In this paper, we present an interactive construction named iPEKS where the search time is linear to the total number of distinct searched keywords instead of the total number of the searchable keywords. The more the keywords have been searched previously, the better the efficiency can be improved. We provide theoretical analysis to show the security and privacy. In addition, implementation and performance experiments exhibit a great improvement in efficiency compared with the previous schemes.
Towards Position-Aware Symbol-Based Searches on Encrypted Data from Symmetric Predicate Encryption Schemes
(2016-01)
Tseng, Fu-Kuo
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Chen, Rong-Jaye
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資訊工程學系
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Department of Computer Science
Symmetric predicate encryption schemes support a rich class of predicates over keyword ciphertexts while preserving both keyword privacy and predicate privacy. Most of these schemes treat each keyword as the smallest unit to be processed in the generation of ciphertexts and predicate tokens. To extend the class of predicates, we treat each symbol of a keyword as the smallest unit to be processed. In this letter, we propose a novel encoding to construct a symmetric inner-product encryption scheme for position-aware symbol-based predicates. The resulting scheme can be applied to a number of secure filtering and online storage services.