Public key encryption with keyword search secure against keyword guessing attacks without random oracle

The notion of public key encryption with keyword search (PEKS) was put forth by Boneh et al. to enable a server to search from a collection of encrypted emails given a “trapdoor” (i.e., an encrypted keyword) provided by the receiver. The nice property in this scheme allows the server to search for a keyword, given the trapdoor. Hence, the verifier can merely use an untrusted server, which makes this notion very practical. Following Boneh et al.’s work, there have been subsequent works that have been proposed to enhance this notion. Two important notions include the so-called keyword guessing attack and secure channel free, proposed by Byun et al. and Baek et al., respectively. The former realizes the fact that in practice, the space of the keywords used is very limited, while the latter considers the removal of secure channel between the receiver and the server to make PEKS practical. Unfortunately, the existing construction of PEKS secure against keyword guessing attack is only secure under the random oracle model, which does not reflect its security in the real world. Furthermore, there is no complete definition that captures secure channel free PEKS schemes that are secure against chosen keyword attack, chosen ciphertext attack, and against keyword guessing attacks, even though these notions seem to be the most practical application of PEKS primitives. In this paper, we make the following contributions. First, we define the strongest model of PEKS which is secure channel free and secure against chosen keyword attack, chosen ciphertext attack, and keyword guessing attack. In particular, we present two important security notions namely IND-SCF-CKCA and IND-KGA. The former is to capture an inside adversary, while the latter is to capture an outside adversary. Intuitively, it should be clear that IND-SCF-CKCA captures a more stringent attack compared to IND-KGA. Second, we present a secure channel free PEKS scheme secure without random oracle under the well known assumptions, namely DLP, DBDH, SXDH and truncated q-ABDHE assumption. Our contributions fill the gap in the literature and hence, making the notion of PEK

Y-DWMS - A digital watermark management system based on smart contracts

With the development of information technology, films, music, and other publications are inclined to be distributed in digitalized form. However, the low cost of data replication and dissemination leads to digital rights problems and brings huge economic losses. Up to now, existing digital rights management (DRM) schemes have been powerless to deter attempts of infringing digital rights and recover losses of copyright holders. This paper presents a YODA-based digital watermark management system (Y-DWMS), adopting non-repudiation of smart contract and blockchain, to implement a DRM mechanism to infinitely amplify the cost of infringement and recover losses copyright holders suffered once the infringement is reported. We adopt game analysis to prove that in Y-DWMS, the decision of non-infringement always dominates rational users, so as to fundamentally eradicate the infringement of digital rights, which current mainstream DRM schemes cannot reach

Reliable Fix Patterns Inferred from Static Checkers for Automated Program Repair

Fix pattern-based patch generation is a promising direction in automated program repair (APR). Notably, it has been demonstrated to produce more acceptable and correct patches than the patches obtained with mutation operators through genetic programming. The performance of pattern-based APR systems, however, depends on the fix ingredients mined from fix changes in development histories. Unfortunately, collecting a reliable set of bug fixes in repositories can be challenging. In this article, we propose investigating the possibility in an APR scenario of leveraging fix patterns inferred from code changes that address violations detected by static analysis tools. To that end, we build a fix pattern-based APR tool, Avatar, which exploits fix patterns of static analysis violations as ingredients for the patch generation of repairing semantic bugs. Evaluated on four benchmarks (i.e., Defects4J, Bugs.jar, BEARS, and QuixBugs), Avatar presents the potential feasibility of fixing semantic bugs with the fix patterns inferred from the patches for fixing static analysis violations and can correctly fix 26 semantic bugs when Avatar is implemented with the normal program repair pipeline. We also find that Avatar achieves performance metrics that are comparable to that of the closely related approaches in the literature. Compared with CoCoNut, Avatar can fix 18 new bugs in Defects4J and 3 new bugs in QuixBugs. When compared with HDRepair, JAID, and SketchFix, Avatar can newly fix 14 Defects4J bugs. In terms of the number of correctly fixed bugs, Avatar is also comparable to the program repair tools with the normal fault localization setting and presents better performance than most program repair tools. These results imply that Avatar is complementary to current program repair approaches. We further uncover that Avatar can present different bug-fixing performances when it is configured with different fault localization tools, and the stack trace information from the failed executions of test cases can be exploited to improve the bug-fixing performance of Avatar by fixing more bugs with fewer generated patch candidates. Overall, our study highlights the relevance of static bug-finding tools as indirect contributors of fix ingredients for addressing code defects identified with functional test cases (i.e., dynamic information)

Chosen-ciphertext secure anonymous conditional proxy re-encryption with keyword search

Weng et al. introduced the notion of conditional proxy re-encryption (or C-PRE, for short), whereby only the ciphertext satisfying one condition set by the delegator can be transformed by the proxy and then decrypted by delegatee. Nonetheless, they left an open problem on how to construct CCA-secure C-PRE schemes with anonymity. Fang et al. answered this question by presenting a construction of anonymous condi- tional proxy re-encryption (C-PRE) scheme without requiring random oracle. Nev- ertheless, Fang et al.\u27s scheme only satises the RCCA-security (which is a weaker variant of CCA-security assuming a harmless mauling of the challenge ciphertext is tolerated). Hence, it remains an open problem whether CCA-secure C-PRE schemes that satisfy both anonymity and full CCA-security can really be realized. Shao et al. introduced a new cryptographic primitive, called proxy re-encryption with keyword search (PRES), which is a combination of PRE and public key encryption with key- word search (PEKS), and they left an open problem on how to design an efficient unidirectional PRES scheme. In this paper, we answer the above open problems by proposing a new crypto- graphic primitive called conditional proxy re-encryption with keyword search (C- PRES), which combines C-PRE and PEKS. We note that there are subtleties in combining these two notions to achieve a secure scheme, and hence, the combination is not trivial. We propose a denition of security against chosen ciphertext attacks for C-PRES schemes with keyword anonymity, and thereafter present a scheme that satises the denition. The performance of our scheme outperforms Weng et al.\u27s construction, which has been regarded as the most efficient C-PRE scheme to date

A high gain, noise cancelling 2515-4900 MHz CMOS LNA for China mobile 5G communication application

© 2020 Tech Science Press. All rights reserved. With the development of the times, people\u27s requirements for communication technology are becoming higher and higher. 4G communication technology has been unable to meet development needs, and 5G communication technology has emerged as the times require. This article proposes the design of a low-noise amplifier (LNA) that will be used in the 5G band of China Mobile Communications. A low noise amplifier for mobile 5G communication is designed based on Taiwan Semiconductor Manufacturing Company (TSMC) 0.13 μm Radio Frequency (RF) Complementary Metal Oxide Semiconductor (CMOS) process. The LNA employs self-cascode devices in current-reuse configuration to enable lower supply voltage operation without compromising the gain. This design uses an active feedback amplifier to achieve input impedance matching, avoiding the introduction of resistive negative feedback to reduce gain. A common source (CS) amplifier is used as the input of the low noise amplifier. In order to achieve the low power consumption of LNA, current reuse technology is used to reduce power consumption. Noise cancellation techniques are used to eliminate noise. The simulation results in a maximum power gain of 22.783, the reverse isolation (S12) less than -48.092 dB, noise figure (NF) less than 1.878 dB, minimum noise figure (NFmin)=1.203 dB, input return loss (S11) and output return loss (S22) are both less than -14.933 dB in the frequency range of 2515-4900 MHz. The proposed Ultra-wideband (UWB) LNA consumed 1.424 mW without buffer from a 1.2 V power supply

A secure channel free public key encryption with keyword search scheme without random Oracle

The public key encryption with keyword Search (PEKS) scheme, proposed by Boneh, Di Crescenzo, Ostrovsky and Persiano, enables one to search for encrypted keywords without compromising the security of the original data. Baek et al. noticed that the original notion of PEKS requires the existence of a secure channel, and they further extended this notion by proposing an efficient secure channel free public key encryption scheme with keyword search in the random oracle model. In this paper, we take one step forward by adopting Baek et al.’s model and propose a new and efficient scheme that does not require any secure channels, and furthermore, its security does not use random oracles

Identity-based conditional proxy re-encryption with fine grain policy

2017 Elsevier B.V.An identity-based conditional proxy re-encryption scheme (IB-CPRE) allows a semi-trusted proxy to convert a ciphertext satisfying one condition, which is set by the delegator, under one identity to another without the necessity to reveal the underlying message. In ICISC 2012, Liang, Liu, Tan, Wong and Tang proposed an IB-CPRE scheme, and left an open problem on how to construct chosen-ciphertext secure IB-CPRE supporting OR gates on conditions. In this work, we answer this aforementioned problem by constructing an identity-based conditional proxy re-encryption scheme with fine grain policy (IB-CPRE-FG). In an IB-CPRE-FG scheme, each ciphertext is labeled with a set of descriptive conditions and each re-encryption key is associated with an access tree that specifies which type of ciphertexts the proxy can re-encrypt. Furthermore, our scheme can be proved secure against adaptive access tree and adaptive identity chosen-ciphertext attack