Equality Test Research Articles

Secure Replication-Based Outsourced Computation Using Smart Contracts

The replication-Based Outsourced Computation (RBOC) mechanism allows a client to outsource the same computing job to multiple contractors and the honest contractors will get paid in the incentivized system based on the fact that a majority of contractors will honestly perform the computation. As self-executing contracts, smart contracts are utilized in the decentralized blockchain networks to execute coded programs automatically transparently, and publicly. It is natural to apply smart contracts to RBOC to improve performance by setting smart contracts as the converter between the client and contractors to reduce the load on the client. However, it is infeasible to directly combine these two blocks together because the data including returned computing results from contractors in the decentralized blockchain are in the form of plaintexts such that some lazy contractors could copy others' results as their own and still get paid, which will compromise the security of RBOC. The existing public-key encryption with equality test (PKEET) is a promising candidate solution to stop the above lazy contractors, where the results are encrypted by PKEET and then transferred without hindering smart contracts to compare the equality of underlying results. Unfortunately, we found that the advanced lazy contractors can still compromise security by forging ciphertexts to pass the equality test only with the encrypted results of other contractors. In this paper, to achieve security against lazy contractors, we introduce the notion of PKEET against lazy encryptors (PKEET-LE). Besides the fundamental property of PKEET that performs equality test on ciphertexts without decryption, PKEET-LE additionally realizes the security against the lazy encryptors who aim to forge a ciphertext for a given one to pass the equality test between them without the knowledge of the underlying plaintext. We further propose a concrete and practical PKEET-LE construction along with formal security proof. Finally, we conduct a performance evaluation to demonstrate that our PKEET-LE scheme is efficient and practical in the RBOC system using smart contracts.

An Efficient Online/Offline Heterogeneous Signcryption Scheme With Equality Test for IoVs

The privacy and authenticity of propagated messages are two important goals in Internet of Vehicles (IoVs). Most of existing signcryption schemes can satisfy above requirements, but they are rigidly compatible for a single cryptosystem rather than a heterogeneous system consisting of different cryptographic mechanisms. In this paper, we construct an efficient online/offline heterogeneous signcryption scheme with equality test (OOHSC-ET), in which the signcrypted message is delivered from certificateless cryptosystem (CLC) to public key infrastructure (PKI) system for information compatibility. Besides, this construction allows the cloud server to perform the equality test, to determine whether the different ciphertexts contain the same plaintext without unsigncryption, as a feasible solution for searching ciphertext in heterogeneous environment. In addition, the signcryption phase can be separated into online and offline manners, the former conducts the lightweight operation, while the latter initializes the heavy and preparative operation. In this way, the security and efficiency are both preserved. Finally, the security proof and performance analysis demonstrate that the OOHSC-ET scheme is more suitable for the payment operation in terms of IoVs.

LPPA-RCM: A lightweight privacy-preserving authentication scheme for road condition monitoring in fog-based VANETs

In vehicular ad-hoc networks (VANETs), vehicles can upload current road conditions to a traffic management agency (TMA) to improve traffic condition. However, road conditions submitted by different vehicles may be identical, which brings an extra workload on TMA. Filtering redundant road conditions is a possible solution, but road conditions are usually encrypted. It is time-consuming to filter ciphertext. This paper proposes a lightweight privacy-preserving authentication scheme for road condition monitoring (LPPA-RCM), which adopts a lightweight equality test method on ciphertexts. This method uses Lagrange interpolation to filter redundant road conditions. In addition, there is only one Lookup operation of the Cuckoo filter to determine redundant road condition, which is more efficient than comparing all stored messages one by one. Finally, security analysis demonstrates that LPPA-RCM satisfies the security requirements of VANETs. Besides, performance analysis demonstrates that LPPA-RCM is more efficient.

An Efficient Identity-Based Encryption With Equality Test in Cloud Computing

Identity-based encryption with equality test (IBEET) provides a feasible way for cloud server partitioning or searching on ciphertexts in the cloud. In that case, the server can judge if two different ciphertexts encrypt the same plaintexts or not. In response to threats posed by quantum computers, lattice-based IBEET schemes have been proposed to make cloud service post-quantum secure. However, those schemes are inefficient and can hardly meet the needs of resource-constrained devices. In this paper, an efficient post-quantum IBEET scheme is introduced, which achieves testability by embedding the hash value of plaintext into testing trapdoor instead of encrypting it directly and doubling the size of ciphertext. We also prove that, with the Learning With Errors (LWE) problem assumption, the new scheme is one-way secure against selective identity and chosen ciphertext attacks (OW-sID-CCA) in quantum secure model. Furthermore, we evaluate the performance of the new construction and demonstrate its efficiency by showing that it only costs about half storage comparing with other lattice-based IBEET schemes. The execution time of encryption and decryption phrases in the new scheme reduce by <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$50\%$</tex-math></inline-formula> , while the computational cost in test algorithm keeps the same. Therefore, the new proposed IBEET is much more practical for working in post-quantum cloud computing scenarios.

Keragaan Agronomi Padi Varietas Inpari Di Sawah Irigasi Kabupaten OKU Timur Sumatera Selatan

Lowland rice has a very important role in meeting national rice needs because around 90% of rice production comes from paddy fields. The aim was to determine the performance growth and production of the Inpari variety that is adaptive and high yielding in irrigated rice fields. Inpari 42 and Inpari IR Nutri Zinc are white label with comparison to Inpari 32. The need for fertilizer is 300 kg of Ponska NPK and 200 kg of Urea/ha. Observational data included: growth performance consisting of plant height, number of productive tillers, panicle length. The performance of the yield and yield components consisted of the number of grain/panicles, the number of full grain/panicles and productivity. Data were analyzed by means of equality test (t-test). The results showed that the plant height of inpari 42 and inpari IR Nutri Zinc was relatively short while inpari 32 was classified as medium. The number of productive tillers and panicle length of inpari 42 and inpari IR nutri Zinc were not significantly different from inpari 32. The highest production of inpari 42 was 8.5 tons gkp/ha followed by inpari Ir nutri Zinc which was 7.0 tons gkp/ha better than comparison varieties.

Linear-time 2-party secure merge from additively homomorphic encryption

We present a linear-time, space and communication data-oblivious algorithm for securely merging two private, sorted lists into a single sorted, secret-shared list in the two party setting. Although merging two sorted lists can be done insecurely in linear time, previous secure merge algorithms all require super-linear time and communication. A key feature of our construction is a novel method to obliviously traverse permuted lists in sorted order. Our algorithm only requires black-box use of the underlying additively homomorphic cryptosystem and generic secure computation protocols for comparison and equality testing.

Effect of Landlockedness on Receiving Tourism Income in SAARC Countries

This study looks into the economic-driven tourism growth hypothesis in the context of SAARC countries. It also investigates the effect of landlockedness on tourism income receipt. It is based on secondary data gathered from several World Bank Reports and economic surveys of respective countries. It made use of 169 data points from SAARC's eight member countries. The data from an unbalanced panel was used. It makes use of an exploratory and analytical research design. For the impact study of independent variables on dependent variables, descriptive statistics, panel unit root testing, panel quantile regression analysis, quantile process estimates, quantile slope equality test, and symmetric quantile test are used. The GDP has a positive impact on tourism income in SAARC countries. It is found that one percent increase in the median value of GDP, the tourism income is increased by 0.219 percent. The evidence has proved the economic-driven tourism growth hypothesis, particularly regarding SAARC countries. This highlights the need for tailored tourism initiatives aimed specifically at landlocked nations.

An Identity-Based Encryption with Equality Test scheme for healthcare social apps

It is tricky to determine whether two ciphertexts contain the same message when the messages are encrypted with different public keys. public key encryption with equality test (PKEET) addresses this problem without decryption. By integrating PKEET with identity-based encryption, identity-based encryption with equality test (IBEET) simplifies the certificate management in PKEET. In this paper, we first propose an IBEET scheme that can resist offline message recovery attacks (OMRA) and requires neither the dual-tester setting nor the group mechanism. With the help of some mathematical assumptions, we demonstrate the security of our scheme. Experiment results reveal that our scheme is efficient. From the perspective of usability, we explain why our scheme is more appropriate to be applied in healthcare social Apps than other OMRA-resistant schemes.

A lattice-based public key encryption scheme with delegated equality test

When data security is facing growing threats, ordinary encryption techniques cannot meet the needs of comparing, sharing, and classifying data hidden in ciphertexts. At the same time, the advent of the quantum computing era has brought unprecedented challenges to traditional cryptography. Fortunately, a lattice-based PKEET scheme can solve the above problems. In this paper, we design a lattice-based PKE-DET scheme that can support the delegated tester function with satisfying anti-quantum computing security and resisting OMRA attacks. To the best of our knowledge, this is the first PKE-DET scheme that has both kinds of security at the same time. Under the standard model, we prove the security of the scheme based on the LWE hardness assumption. Compared with existing schemes, our scheme has many advantages, such as high security, delegated tester authorization, and small storage space.

Which factor model? A systematic return covariation perspective

We examine which factor model best captures systematic return covariation by focusing on the economic implications for portfolio risk control. The pairwise variance equality test and the model confidence set procedure suggest that the Fama and French (2015) five-factor model, the Barillas and Shanken (2018) six-factor model, and the Fama and French (2018) six-factor model are the top performers for the factor model-implied minimum risk portfolios in the out-of-sample. When it comes to the minimum tracking error portfolios, the Barillas and Shanken (2018) six-factor model and the Fama and French (2018) six-factor model are the overall winners in the horse race.

Revocable Public Key Encryption with Equality Test without Pairing in Cloud Storage

Abstract Public key encryption with equality test (PKEET) plays an important role in the cloud storage. It allows a third party to test whether two ciphertexts contain the same message without decryption. Since the third party is not fully trusted, it is sometimes necessary to prevent the third party from testing the ciphertexts all the time. To this end, we propose the notion of revocable public key encryption with equality test (R-PKEET). We give the construction of R-PKEET in the random oracle model, which employs time key to update trapdoor and partial ciphertexts. In details, our scheme enables a user to revoke the third party’s test right by sending a time key to the cloud server, which is responsible for updating partial ciphertexts using the time key. Compared with related works, our scheme achieves both lightweight revocation and lower computational complexity by using Shamir’s secret sharing and Lagrange interpolating polynomial.

Application of the Balance of Risk Score to Liver Transplantation

BackgroundTo evaluate the capacity of BARS to predict 90-day, 1-year, 3-year, and 5-year survival after liver transplantation (LTx). The Balance of Risk Score (BARS), proposed by the Swiss Hepato-pancreato-biliary and Transplant Center, University Hospital Zurich, Switzerland, was conceptualized to determine survival after LTx preemptively. Sample and MethodsThis was a retrospective observational study on 866 cases of LTx among adults (>18 years) performed within the transplantation program at Hospital Israelita Albert Einstein between January 1, 2010, and December 31, 2015. Cases of loss from follow-up, split-liver transplantation, transplantation from a live donor, and combinations of LTx with transplantation of other organs were excluded. BARS was calculated for each transplantation performed. The survival estimates were accompanied by 95% CIs, and the associations between the variables of interest and the patients’ overall survival were evaluated using Cox proportional risk models. Receiver operating characteristic curves and the estimated area under the curve were used with 95% CIs and P values for the equality test on the area at .5. ResultsThe area under the curve for the 90-day period was 0.725, with a 95% CI from 0.670 to 0.81 and a P value < .001 for the equality test at 0.5. In the stratified analysis, the score of 18 presented the highest sensitivity, taking a minimum specificity of 90%. The BARS >18 gave rise to a significant decline in survival, from 89.7% to 60.4% over the first 90 days, from 83.3% to 56.2% over a 1-year period, from 75.7% to 49.5% over 3 years, and from 72.2% to 43.4% over 5 years. ConclusionThe BARS was shown to be reproducible and can be used as a tool for estimating survival among LTx patients. LTx performed on patients with BARS >18 significantly predicts lower survival for such patients.

Enhanced Security for Large-Scale 6G Cloud Computing: A Novel Approach to Identity based Encryption Key Generation

Cloud computing and 6G networks are in high demand at present due to their appealing features as well as the security of data stored in the cloud. There are various challenging methods that are computationally complicated that can be used in cloud security. Identity-based encryption (IBE) is the most widely used techniques for protecting data transmitted over the cloud. To prevent a malicious attack, it is an access policy that restricts access to legible data to only authorized users. The four stages of IBE are setup, key extraction or generation, decryption and encryption. Key generation is a necessary and time-consuming phase in the creation of a security key. The creation of uncrackable and non-derivable secure keys is a difficult computational and decisional task. In order to prevent user identities from being leaked, even if an opponent or attacker manages to encrypted material or to decode the key this study presents an advanced identity-based encryption technique with an equality test. The results of the experiments demonstrate that the proposed algorithm encrypts and decrypts data faster than the efficient selective-ID secure IBE strategy, a competitive approach. The proposed method's ability to conceal the identity of the user by utilizing the Lagrange coefficient, which is constituted of a polynomial interpolation function, is one of its most significant aspects.

Cross Domain Heterogeneous Signcryption Scheme with Equality Test for WBAN

The rapid development of wireless sensors has accelerated the popularity of wireless body area network (WBAN). WBAN use multiple sensors to collect the patient’s body data, and the data is transferred to the medical cloud for processing and analyzing. In order to protect the data in the medical cloud, some heterogeneous signcryption schemes that support equality test have been proposed. However, we observe that these schemes use the same cryptographic parameters in different cryptographic systems. In addition, most of these schemes cannot resist the replay attack (RRA) or know session temporary key attack (RKSTKA). To deal with these problems, this paper presents a cross domain heterogeneous signcryption scheme with equality test (CDSCET) for WBAN. In CDSCET, the ciphertexts are from certificateless cryptographic system to public key infrastructure, where two different cryptosystems use different cryptographic parameters. CDSCET can realize confidentiality, integrity, authentication, RRA and RKSTKA. Moreover, compared with three latest schemes, CDSCET has reduced the total computation cost by at least 56.46%.

More efficient tightly-secure lattice-based IBE with equality test

Identity-based encryption with equality test (IBEET) combines public key encryption with equality test (PKEET) and identity-based encryption (IBE). In an IBEET scheme, a user with trapdoors is allowed to verify whether different ciphertexts encrypted under different identities correspond to equal plaintexts through the equality test algorithm. Recently, several IBEET schemes were constructed over lattices to resist the potential quantum threats, perhaps since the latticed-based candidates are the most favored ones in the current NIST PQC standardization. However, almost all of the schemes are developed from Lee et al.’s generic construction and hence double both public parameters and ciphertext sizes. In this paper, we propose a more efficient and tightly-secure IBEET scheme which not only achieves a tight reduction with the semi-adaptive security, but also reduces both public parameters and ciphertext sizes.

A Generic Construction of CCA-Secure Identity-Based Encryption with Equality Test against Insider Attacks

Identity-based encryption with equality test (IBEET) is a generalization of the traditional identity-based encryption (IBE) and public key searchable encryption, where trapdoors enable users to check whether two ciphertexts of distinct identities are encryptions of the same plaintext. By definition, IBEET cannot achieve indistinguishability security against insiders, i.e., users who have trapdoors. To address this issue, IBEET against insider attacks (IBEETIA) was later introduced as a dual primitive. While all users of IBEETIA are able to check whether two ciphertexts are encryptions of the same plaintext, only users who have tokens are able to encrypt plaintexts. Hence, IBEETIA is able to achieve indistinguishability security. On the other hand, the definition of IBEETIA weakens the notion of IBE due to its encryption inability. Nevertheless, known schemes of IBEETIA made use of rich algebraic structures such as bilinear groups and lattices. In this paper, we propose a generic construction of IBEETIA without resorting to rich algebraic structures. In particular, the only building blocks of the proposed construction are symmetric key encryption and pseudo-random permutations in the standard model. If a symmetric key encryption scheme satisfies CCA security, our proposed IBEETIA scheme also satisfies CCA security.

P 2 Ride: Practical and Privacy-Preserving Ride-Matching Scheme for Ridesharing

As a popular instance of sharing economy, ridesharing has been widely adopted in recent years. To use the convenient ridesharing service, riders and drivers have to share with the service provider their private trip information, which impedes users from freely enjoying the benefits of ridesharing. However, existing studies in ridesharing mainly focus on the optimization of rider-driver matching but ignore the protection of privacy of users. In this paper, we propose P2Ride, a Practical and Privacy-preserving Ride-matching scheme for ridesharing, which enables the service provider to efficiently match drivers with appropriate riders without learning the privacy of both drivers and riders. In P2Ride, we first convert the complex ride-matching computation into equality testing by leveraging overlapping partition systems, and then achieve the privacy-preserving ride-matching by designing a novel non-interactive private equality testing protocol. We prove the security of the proposed P2Ride theoretically. Moreover, a prototype of the P2Ride is implemented, and the experiment results over a real-world dataset demonstrate that the proposed P2Ride can achieve both high ride-matching accuracy and practical efficiency.

Dual-server certificateless public key encryption with authorized equality test for outsourced IoT data

The Internet of Things (IoT) devices with restricted storage and computing sources are unable to store and handle massive data at local. A promising method is to engage some cloud server for maintaining outsourced encrypted IoT data and responding user request, in the meantime, the privacy of outsourced data can be protected. Existing encryption techniques with equality test allow the authorized cloud server to compare encrypted data and perform data classification. However, these schemes in the single server model cannot resist internal keyword guessing attacks. Also, the existing schemes in public key setting confront the burden of maintaining public key certificates, and the ones in identity-based setting face the key escrow problem. To address these issues, this paper proposes a dual-server certificateless public key encryption scheme supporting authorized equality test (DS-CL-AET) in bilinear groups. Security analysis indicates that the proposed DS-CL-AET scheme offers confidentiality protection for outsourced ciphertext and authentication tokens. Performance analysis demonstrates the practicality of our DS-CL-AET scheme in securing outsourced IoT data in clouds.

Efficient Equality Test on Identity-Based Ciphertexts Supporting Flexible Authorization

In the cloud, uploading encrypted data is the most effective way to ensure that the data are not leaked. However, data access control is still an open problem in cloud storage systems. To provide an authorization mechanism to limit the comparison of a user's ciphertexts with those of another, public key encryption supporting the equality test with four flexible authorizations (PKEET-FA) is presented. Subsequently, more functional identity-based encryption supporting the equality test (IBEET-FA) further combines identity-based encryption with flexible authorization. The bilinear pairing has always been intended to be replaced due to the high computational cost. Hence, in this paper, we use general trapdoor discrete log groups to construct a new and secure IBEET-FA scheme, which is more efficient. The computational cost for the encryption algorithm in our scheme was reduced to 43% of that of the scheme of Li et al. In Type 2 and 3 authorization algorithms, the computational cost of both was reduced to 40% of that of the scheme of Li et al. Furthermore, we give proof that our scheme is secure against one-wayness under the chosen identity and chosen ciphertext attacks (OW-ID-CCA), and indistinguishable against chosen identity and chosen ciphertext attacks (IND-ID-CCA).

The potential of the discovery learning model integrated the reading, questioning, and answering model on cross-cultural high school students’ problem-solving skills

This study aims to test the discovery model integrated with the reading, questioning, and answering (RQA) model. This research is a quasi-study which involves the second semester XI grade students of state senior high school (SMA) Negeri in Situbondo as subjects. The number of students who studied was 160 people from four different classes in the 2018/2019 academic year. Sampling is done by class equality test. Each class is taught with a different model, for each class is grouped again based on the culture of residence of students, namely coastal students, urban and mountain students. Researchers used Ancova to test the research hypothesis followed by the least significant difference (LSD) test. The results showed that: i) RQA’s integrated discovery learning model is able to improve students’ problem-solving skills compared to the original model; ii) Culture has a significant role in shaping students’ problem-solving skills, with the use of the same model given to students who have a background a different background will get different results; and iii) Learning in school and in the environment is an interrelated factor in shaping students’ thinking patterns and problem-solving skills. Discovery learning model integrated learning RQA model is a combination of effective models to be applied to students who are trained with challenges where nature teaches them to think and act appropriately and quickly.