Strong Security Model Research Articles

The Philippine National Public Key Infrastructure in Pamantasan ng Lungsod ng Muntinlupa Towards Digital Services Security Model for Public Universities

The integration of the Philippine National Public Key Infrastructure (PNPKI) into Pamantasan ng Lungsod ng Muntinlupa’s (PLMun) digital services framework is the main topic of the study. The research tackles the urgent need for a strong security model to protect sensitive data and strengthen public institutions’ overall security posture as digitalization becomes more widespread in academic settings. Its goals are to determine if integrating PNPKI into PLMun’s digital services is feasible, examine how PNPKI improves data security and integrity, and develop a complete security model for public universities based on PNPKI. The research study uses a methodical approach, looking closely at PNPKI features and how well they fit with PLMun’s digital infrastructure. Comparison studies of current security models for public universities based on PNPKI. The research study uses a methodical approach, looking closely at PNPKI features and how well they fit with PLMun’s digital infrastructure. We’ll compare the security approaches that are currently in use in educational institutions, and we might use surveys or interviews to get feedback from pertinent parties. The study expects to demonstrate the possible advantages of PNPKI implementation in PLMun, including increased data security, better authentication procedures, and improved digital resilience in general. Analyses of comparisons will shed light on the benefits of PNPKI over other security methods. In summary, it offers PLMun and other public universities a workable implementation roadmap for PNPKI. Policymakers, university administrators, and IT experts will find great value in the expected outcomes, which highlight the importance of a uniform security architecture. Keywords: Information Technology, Public Key Infrastructure, Digital Services, Security Model, Data Integrity

PriGenX: Privacy-Preserving Query With Anonymous Access Control for Genomic Data

Presently, similar sequence search is a fundamental technique in genomic data research. Patients or researchers, who want to check whether they or their research objects have genetic diseases or potential illnesses, need to query similar sequences with their genes in certain genomic databases. As a consequence, this may raise privacy issues since the genomic data are regarded as an identifier of each individual and contain lots of sensitive information. Up to date, some solutions have been brought up for achieving secure similarity search over genomic data, but they are still defective in searching exact similar sequences, supporting fine-grained access control, preventing side information leakage, and being built on strong security models at the same time. In this paper, aiming at the above challenge, we propose a maliciously secure similar sequence search scheme with fine-grained access control over genomic data, named PriGenX. Based on oblivious transfer and authenticated garbling techniques, our scheme also supports secure access control with anonymity for protecting the identity of each party preventing side information leakage, and implementing a flexible over-threshold similarity search. Experimental results and security analysis indicate that our scheme is scalable and maliciously secure.

Exploring the Security Vulnerability in Frequency-Hiding Order-Preserving Encryption

Frequency-hiding order-preserving encryption (FH-OPE) has emerged as an important tool in data security, particularly in cloud computing, because of its unique ability to preserve the order of plaintexts in their corresponding ciphertexts and enable efficient range queries on encrypted data. Despite its strong security model, indistinguishability under frequency analyzing ordered chosen plaintext attack (IND-FA-OCPA), our research identifies a vulnerability in its design, particularly the impact of range queries. In our research, we quantify the frequency of data exposure resulting from these range queries and present potential inference attacks on the FH-OPE scheme. Our findings are substantiated through experiments on real-world datasets, with the goal of measuring the frequency of data exposure resulting from range queries on FH-OPE encrypted databases. These results quantify the level of risk in practical applications of FH-OPE and reveal the potential for additional inference attacks and the urgency of addressing these threats. Consequently, our research highlights the need for a more comprehensive security model that considers the potential risks associated with range queries and underscores the importance of developing new range-query methods that prevent exposing these vulnerabilities.

Privacy-preserving data aggregation scheme against deletion and tampering attacks from aggregators

Because privacy-preserving data aggregation protocols provide data privacy and data compression, they have been extensively studied in smart grids. However, most of the existing data aggregation protocols are based on honest-but-curious aggregators, or adopt computationally intensive asymmetric homomorphic encryption, making these protocols only provably secure in weak security models, or resulting in high computational complexity for terminal users. To address the aforementioned issues, in this work, we propose a novel lightweight privacy-preserving data aggregation scheme against malicious aggregators based on our symmetric homomorphic encryption. The proposed scheme can reduce the computational cost of smart meters while also resisting tampering and deletion attacks from malicious aggregators. One of the highlights of the proposed scheme is its ability to withstand deletion attacks from malicious aggregators, which makes it unnecessary for the malicious aggregator to aggregate the readings of all smart meters instead of only a part of them. Therefore, our scheme is more secure than other schemes. It is the first privacy-preserving data aggregation scheme based on a stronger security model without multiple rounds of interaction. Finally, the detailed security analysis shows that the proposed scheme satisfies desirable security properties. Moreover, experimental results demonstrate that the proposed scheme is superior to the other four schemes in terms of computational complexity and communication overhead.

Secure post‐quantum group key exchange: Implementing a solution based on Kyber

AbstractQuantum computing poses fascinating challenges for current cryptography, threatening the security of many schemes and protocols widely used today. To adapt to this reality, the U.S. National Institute for Standards and Technology (NIST) is currently running a standardization process in search of post‐quantum (classical, yet resistant to quantum attacks) cryptographic tools, focusing on signature schemes and key encapsulation mechanisms. Many of the competing proposals also include designs for two‐party key exchange, which can be combined in different ways to fit scenarios involving parties, that is, yielding group key exchange protocols. However, very few implementations of such group protocols are available to practitioners, which face a non‐trivial challenge when deciding how to implement a protocol for establishing secure group sessions in this new post‐quantum scenario. With this in mind, the authors report on the implementation of a secure post‐quantum group key exchange protocol in the so‐called Quantum Random Oracle Model. The protocol decided to implement is based on a KEM called Kyber, which is one of the finalists of the NIST competition. Not only this group construction is the only one available in the literature using a NIST finalist, but also, among all post‐quantum designs the authors are aware of, it uses this strongest security model (as, e.g. in other proposals, the adversarial interaction with the hash functions of the system is assumed to be exclusively classical). Furthermore, experimental evidence is provided supporting this choice in terms of performance, even if the number of involved entities is large (up to 2000). All data and code are publicly available.

Practical fully leakage resilient signatures with auxiliary inputs

Digital signatures are essential techniques used in the real world, especially for validating the authenticity of a given message. The security of the digital signatures based on the traditional security definition, however, may be vulnerable to the side-channel attacks. Currently, although several leakage-resilient signature (LR-Sig) schemes have been proposed to model the side-channel attacks, the schemes are highly inefficient. Because either the signature size is quite large or a limited fraction of the secret key can be leaked. In this paper, we present practical LR-Sig schemes that are able to withstand a large scale of leakage.Technically, we build the first generic construction of LR-Sig, which is secure in the auxiliary input model (allowing leakage by any hard-to-invert function), continual memory leakage (updating the secret key periodically while remaining the public key fixed) and fully leakage resilience (admitting leakage of the secret key and the signing randomness). Apart from the strong security model, the sizes of our signature and public key are the same as each underlying standard signature scheme. In particular, the verification algorithm of our LR-Sig is as fast as the original scheme. Thereby, our instantiation LR-ECDSA can be easily adopted in the existing cryptocurrencies since no additional modification is needed for the verifier side.Furthermore, we provide the first comprehensive quantitative analysis for different LR-Sig schemes. The state-of-the-art signature schemes, which are able to leak over 50% of the secret key, are at least 565k bits. Comparatively, our shortest instantiation LR-BLS has a signature size of only 1 group element (382 bits, shorten by 1479 times) regardless of the percentage of leakage. Meanwhile, our LR-BLS is also the first deterministic LR-Sig. Besides, our instantiation LR-Schnorr enjoys the fastest verification.

Practical dynamic group signatures without knowledge extractors

A dynamic group signature ( $$\mathcal {DGS}$$ ) allows a user to generate a signature on behalf of a group, while preserving anonymity. Although many existing $$\mathcal {DGS}$$ schemes have been proposed in the random oracle model for achieving efficiency, their security proofs require knowledge extractors that cause loose security reductions. In this paper, we first propose a new practical $$\mathcal {DGS}$$ scheme whose security can be proven without knowledge extractors in the random oracle model. Moreover, our scheme can also be proven in the strong security model where an adversary is allowed to generate the group managers’ keys maliciously. The efficiency of our scheme is comparable to existing secure $$\mathcal {DGS}$$ schemes in the random oracle model using knowledge extractors. The security of our scheme is based on a new complexity assumption that is obtained by generalizing the Pointcheval–Sanders (PS) assumption. Although our generalized PS (GPS) assumption is interactive, we prove that, under the (2,1)-discrete logarithm assumption, the new GPS assumption holds in the algebraic group model.

Information security risk management models for cloud hosted systems: A comparative study

Cloud hosting approach is becoming a popular choice for management. Having the information hosted in the cloud increase the risks and threats. A strong Security Model is required to maximize the security and treat risks efficiently. This research aims to analysis the most popular Security Model Methodologies and provide recommendation on the best fit methodology for cloud hosting approach. This research used a comparison model to compare the Security Model methodologies, which are ISO27005, NIST SP 800-30, CRAMM, CORAS, OCTAVE Allegro, and COBIT 5, based on three areas: Applicability, adaptability, and Involvement of the models for a cloud-based hosting approach. The research recommends OCTAVE Allegro as the preferred model for cloud hosting approach, as well as COBIT 5 and CORAS with some tuning. The previous models handle the CIA Triad and focus on the information storage, Processing, and transmission. The ISO27005, NIST SP 800-30, and CRAMM are all describing the risk management and assessment as an abstract and might not provide clear guidelines for cloud risks evaluation and assessment. There are more than 200 security models in the management studies, few are suitable for fast growing and continuously changing environment like the cloud approach, the research value on highlighting the best fit approaches to consider when using a cloud hosting platform, securing the information with a proper model.

SoK: Network-Level Attacks on the Bitcoin P2P Network

Over the last decade, Bitcoin has revolutionized the global economic and technological landscape, inspiring a new generation of blockchain-based technologies. Its protocol is today among the most influential for cryptocurrencies and distributed networks. In particular, the P2P layer represents a reference point for all permissionless blockchains, which often implement its solutions in their network layer. Unfortunately, the Bitcoin network protocol lacks a strong security model, leaving it exposed to several threats. Attacks at this level can affect the reliability and trustworthiness of the consensus layer, mining the credibility of the whole system. It is therefore of utmost importance to properly understand and address the security of the Bitcoin P2P protocol. In this paper, we give a comprehensive and detailed overview of known network-level attacks in Bitcoin, as well as the countermeasures that have been implemented in the protocol. We propose a generic network adversary model, and propose an objective-based taxonomy of the attacks. Finally, we identify the core weaknesses of the protocol and study the relationship between different types of attack. We believe our contribution can help both new and experienced researchers have a broader and deeper understanding of the Bitcoin P2P network and its threats, and allow for a better modeling of its security properties.

Hardware security without secure hardware: How to decrypt with a password and a server

Hardware security tokens have now been used for several decades to store cryptographic keys. When deployed, the security of the corresponding schemes fundamentally relies on the tamper-resistance of the tokens – a very strong assumption in practice. Moreover, even secure tokens, which are expensive and cumbersome, can often be subverted.We introduce a new cryptographic primitive called Encryption schemes with Password-protected Assisted Decryption (EPAD schemes), in which a user's decryption key is shared between a user device (or token) on which no assumption is made, and an online server. The user shares a human-memorizable password with the server. To decrypt a ciphertext, the user launches, from a public computer, a distributed protocol with the device and the server, authenticating herself to the server with her password (unknown to the device); in such a way that her secret key is never reconstructed during the interaction. We propose a strong security model which guarantees that (1) for an efficient adversary to infer any information about a user's plaintexts, it must know her password and have corrupted her device (secrecy is guaranteed if only one of the two conditions is fulfilled), (2) the device and the server are unable to infer any information about the ciphertexts they help to decrypt (even though they could together reconstruct the secret key), and (3) the user is able to verify that the device and the server both performed the expected computations. These EPAD schemes are in the password-only model, meaning that the user is not required to remember a trusted public key, and her password remains safe even if she is led to interact with a wrong server and a malicious device.We then give a practical pairixng-based EPAD scheme. Our construction is provably secure under standard computational assumptions, using non-interactive proof systems which can be efficiently instantiated in the standard security model, i.e., without relying on the random oracle heuristic.

Schnorr-like identification scheme resistant to malicious subliminal setting of ephemeral secret

In this paper we analyze security of Schnorr Identification Scheme (IS) against subliminal setting of ephemeral secrets. We introduce a new strong security model, which allows the adversary to learn or set ephemeral values on the side of the prover. In this model, we define an IS scheme to be secure, if such an adversary, playing role of a verifier, cannot later impersonate the prover. The model primarily reflects a scenario, where the random number generator used for ephemeral secrets has been maliciously implemented or integrated. After showing that the original Schnorr IS is not secure in our model, we propose a modification, immune to such malicious activity. We prove the security of the modified construction in our new strong model. To prove the construction is practical, we provide an implementation and performance comparison with the original construction.

On post-handshake authentication and external PSKs in TLS 1.3

The TLS protocol is the main cryptographic protocol of the Internet. The work on its current version, TLS 1.3, was completed in 2018. This version differs significantly from the previous ones and has a clean-state design taking into account all modern principles of constructing secure cryptographic protocols. At the same time, even when there are security proofs in some fairly strong security model, it is important to explore the possibility of extending this model and then clarifying the security limits of the protocol. This work considers the restriction on the usage of post-handshake authentication in connections established with external PSK. We show that some vulnerability appears in the case of psk_ke mode (PSK-only key establishment) if more than one pair of entities can possess the same PSK. We provide several practical scenarios where this condition can be easily achieved. Also we propose appropriate mitigation to prevent this vulnerability.

Secure and efficient public key multi-channel broadcast encryption schemes

In the modern era of digital technology, sending different messages to different group of users are essential in many real-life applications, like TV broadcast, radio broadcast etc. Multi-channel broadcast encryption (MCBE) is a mechanism which sends different messages to different group of users efficiently. We have proposed two multi-channel broadcast encryption schemes in the public key setting. Our first construction is selectively secure against chosen-plaintext attack, whereas the second one achieves adaptive security which is the strongest security model in the broadcast setting. Besides, our second construction is dynamic, whereas none of the existing MCBE constructions supports the dynamic property. Moreover, our second MCBE construction is the first inclusive-exclusive MCBE construction, where the broadcaster can reduce the encryption and decryption cost by choosing the smallest set between the set of subscribes and revoked users in the encryption and decryption phase respectively.

Proficient Justification of Data Accuracy for Cloud Storage Using Dual Protection

The cloud security is one of the essential roles in cloud, here we can preserve our data into cloud storage. More and more clients would like to keep their data to PCS (public cloud servers) along with the rapid development of cloud computing. Cloud storage services allow users to outsource their data to cloud servers to save local data storage costs. Multiple verification tasks from different users can be performed efficiently by the auditor and the cloud-stored data can be updated dynamically. It makes the clients check whether their outsourced data is kept intact without downloading the whole data. In our system we are using the own auditing based on the token generation. Using this key generation technique compare the key values from original keys we can find out the changes about the file. A novel public verification scheme for cloud storage using in distinguishability obfuscation, which requires a lightweight computation on the auditor and delegate most computation to the cloud. Not only stored also the content will be encrypted in the cloud server. If anyone try to hack at the cloud end is not possible to break the two different blocks. The security of our scheme under the strongest security model. They need first decrypt the files and also combine the splitted files from three different locations. This is not possible by anyone. Anyone can download the files from the server with file holder permission. At the time of download key generated (code based key generation) and it will send to the file owner. We can download the file need to use the key for authentication and some other users want to download file owner permission is necessary.

A Secure Data Transmission Scheme using Asymmetric Semi-Homomorphic Encryption Scheme

<p>The compressive detecting based information accumulation accomplishes with high exactness in information recuperation from less inspection which is available in sensor nodes. In this manner, the existing methods available in the literature diminish the information gathering cost and delays the existence cycle of WSNs. In this paper, a strong achievable security model for sensor network applications was initially proposed. At that point, a secure data collection conspire was displayed based on compressive detecting, which improves the information protection by the asymmetric semi-homomorphic encryption scheme, and decreases the calculation cost by inadequate compressive grid. In this case, particularly the asymmetric mechanism decreases the trouble of mystery key circulation and administration. The proposed homomorphic encryption permits the in-arrange accumulation in cipher domain, and in this manner improves the security and accomplishes the adjustment in system stack. Further, this paper focuses on estimating various network performances such as the calculation cost and correspondence cost, which remunerates the expanding cost caused by the homomorphic encryption. A real time validation on the proposed encryption scheme using AVISPA was additionally performed and the results are satisfactory.</p>

Implementation of an eCK-secure Key Exchange Protocol for OpenSSL

Security models have been developed over time to analyze the security of two-party authenticated key exchange (AKE) protocols. LaMacchia et al. (ProSec 2007) presented a strong security model for AKE protocols, namely the extended Canetti-Krawczyk (eCK) model, addressing wide range of real-world attack scenarios. They constructed a protocol called NAXOS, that is proven-secure in the eCK model. In order to satisfy the eCK security, the NAXOS protocol uses a hash function to combine the long-term secret key and the ephemeral secret key, which is often called as “NAXOS-trick”. However, for the NAXOS-trick-based protocols, the way of leakage modelled in the eCK model leads to an unnatural assumption of leak-free computation of the hash function. Precisely, the eCK model allows the attacker to reveal the ephemeral key while the output of the NAXOS-trick computation remains safe (leak-free). In a recent work of Alawatugoda et al. (IMA Cryptography and Coding 2015), a NAXOS-trick-free eCK-secure AKE protocol is presented, namely protocol P1. In this work, we implement the protocol P1 to be used with the widely-used OpenSSL cryptographic library. OpenSSL implementations are widely used with the real-world security protocol suites, such as Security Socket Layer (SSL) and Transport Layer Security (TLS). As per best of our knowledge, this is the first implementation of a eCK-secure key exchange protocol for the OpenSSL library. Thus, we open up the direction to use the recent advancements of cryptography for real-world Internet communication.

Efficient identity-based authenticated key agreement protocol with provable security for vehicular ad hoc networks

In vehicular ad hoc networks, establishing a secure channel between any two vehicles is fundamental. Authenticated key agreement is a useful mechanism, which can be used to negotiate a shared key for secure data transmission between authentic vehicles in vehicular ad hoc networks. Among the existing identity-based two-party authenticated key agreement protocols without pairings, there are only a few protocols that provide provable security in strong security models such as the extended Canetti–Krawczyk model. This article presents an efficient pairing-free identity-based one-round two-party authenticated key agreement protocol with provable security, which is more suitable for real-time application environments with highly dynamic topology such as vehicular ad hoc networks than the existing identity-based two-party authenticated key agreement protocols. The proposed protocol is proven secure under the passive and active adversaries in the extended Canetti–Krawczyk model based on the Gap Diffie–Hellman assumption. The proposed protocol can capture all essential security attributes including known-session key security, perfect forward secrecy, basic impersonation resistance, key compromise impersonation resistance, unknown key share resistance, no key control, and ephemeral secrets reveal resistance. Compared with the existing identity-based two-party authenticated key agreement protocols, the proposed protocol is superior in terms of computational cost and running time while providing higher security.

Location-Sharing Systems With Enhanced Privacy in Mobile Online Social Networks

Location sharing is one of the critical components in mobile online social networks (mOSNs), which has attracted much attention recently. With the advent of mOSNs, more and more users' location information will be collected by the service providers in mOSN. However, the users' privacy, including location privacy and social network privacy, cannot be guaranteed in the previous work without the trust assumption on the service providers. In this paper, aiming at achieving enhanced privacy against the insider attack launched by the service providers in mOSNs, we introduce a new architecture with multiple location servers for the first time and propose a secure solution supporting location sharing among friends and strangers in location-based applications. In our construction, the user's friend set in each friends' query submitted to the location servers is divided into multiple subsets by the social network server randomly. Each location server can only get a subset of friends, instead of the whole friends' set of the user as the previous work. In addition, for the first time, we propose a location-sharing construction which provides checkability of the searching results returned from location servers in an efficient way. We also prove that the new construction is secure under the stronger security model with enhanced privacy. Finally, we provide extensive experimental results to demonstrate the efficiency of our proposed construction.

Secure the Cloud Data Transmissionusing an Improved RSA Algorithm

Objectives: To overcome the cloud data security challenges, a few recommendations have been proposed along with RSA encryption algorithm. Methods: The RSA algorithm can be defined as an asymmetric key algorithm which is used to develop the strong security model. In cloud computing so many encryption schemes are used for security. In the proposed model the RSA is used to build new security model because it is tightly secured algorithm. Findings: Many organizations are migrating to cloud environment, it is imperative to understand the data security issues surrounding cloud computing. The data security is attained by using modified RSA algorithm. Improvements: In this paper we propose a modified RSA encryption algorithm with longest common sub sequence of a string (LCS). The encrypted and decrypted files are compared and the correctness of proposed system is proved. Keywords: Cloud Computing, DNA, LCS Algorithm, RS Algorithm, Security

A new strong security model for stateful authenticated group key exchange

Stateful authenticated group key exchange (stAGKE) represents an important class of authenticated group key exchange (AGKE) such as tree-based AGKE. The computation of either ephemeral public key or session key in a new stAGKE session may be based on the ephemeral secret state from some previously established session. We notice that earlier AGKE models may be not able to provide appropriate security arguments for stAGKE. In this work, a new model is proposed for stAGKE to formulate security properties in particular for resistance to the leakage attacks on ephemeral key. To be of independent interest, the new model is also flexible, which can be used for analyzing either stateless or stateful AGKE protocols. We show the validity of our model by introducing a new tree-based protocol construction for stAGKE. The proposed scheme is proven secure in our new proposed model without random oracles.