Attribute-Based Encryption (ABE) is an advanced public-key encryption paradigm that enforces fine-grained access control over encrypted data. For instance, the data owner can generate the ciphertext associated with ((”Cardiology” OR ”Critical Care Medicine”) AND ”Consultant Physician”), which can only be decrypted by other data users whose attributes satisfy this access policy. However, a major efficiency drawback of ABE is that ciphertext size, encryption time, and decryption time grow with the complexity of the access policy and the number of attributes. To address this issue, we propose an adaptively secure, offline/online and outsourcing ABE scheme under the Generic Group Model. The majority of encryption operation is performed during the offline phase, while ABE ciphertext is quickly assembled during the online phase. Decryption outsourcing enables the edge node to convert the original ABE ciphertext into an ElGamal-style ciphertext using a transformation key without revealing the plaintext message to the edge node. Our approach is efficient and suitable for mobile devices. Performance evaluation demonstrates the system can balance computation and power consumption over an extended period, effectively addressing challenges in data sharing.

Government data sharing, a cornerstone of digital governance, is strategically vital for enhancing public services and maximizing data utility. While Ciphertext-Policy Attribute-Based Encryption (CP-ABE) offers a promising cryptographic solution for secure government data sharing due to its flexible access control, existing schemes face substantial limitations in policy privacy, dynamic permission management, and verifiability of query results, thus hindering real-world e-governance deployment. To address these challenges, we propose GovLink, an auditable, full policy hiding CP-ABE scheme that supports dynamic revocation and verifiable query results. Specifically, by integrating the matrix representation of a linear secret sharing scheme with hidden vector encryption, GovLink achieves fine-grained access control and robust policy hiding. Furthermore, we design an efficient dynamic revocation mechanism utilizing puncturable encryption and Lagrange interpolation, guaranteeing system forward security. To enhance auditability, GovLink introduces lightweight data update verification (using hash and XOR operations) and employs a multiset accumulator to ensure verifiable data update legitimacy and query result integrity. Security analysis confirms that GovLink meets stringent security requirements, including indistinguishability under chosen-plaintext attack and full policy indistinguishability. Empirical evaluations conducted using the JPBC cryptographic library demonstrate GovLink’s practical feasibility and efficiency in its core operations.

In a typical Internet of Medical Things (IoMT) system, it is common for users’ physiological data, collected by medical sensors, to be processed and shared in a third-party environment, such as a cloud server. Medical data sharing in a third-party environment must guarantee data integrity and source authentication, and robust privacy-preserving measures must be taken to enhance reliability. Searchable encryption (SE) has been leveraged in the IoMT to address the issue of exposing private data during storage and transmission. However, existing works suffer from shortcomings, such as vulnerability to data tampering. In this paper, we propose a novel privacy-preserving data sharing scheme with identity authentication based on SE that addresses the heavyweight public key management problem within a Public Key Infrastructure (PKI) framework. In IB-BPSE, a redactable signature (RS) assisted by blockchain and Merkle tree structure ensures authentication and integrity. Searchable proxy re-encryption encrypts private data, enabling efficient ciphertext search and multi-user data sharing. In addition, the scheme is provably secure in the random oracle model, and the performance analysis demonstrates that the system achieves ideal comprehensive performance. Finally, we propose an application scenario in IoMT based on IB-BPSE.

In the era of expanding data volumes, users tend to encrypt data and upload their data to cloud servers. Broadcast encryption (BE) facilitates one to many secure data sharing and enjoys widespread adoption in many areas (e.g, Pay-TV, digital rights management, cloud storage). Nevertheless, the Snowden revelation in 2013 showed that attackers (e.g., manufacturers and supply-chain intermediaries) could tamper cryptographic implementations and insert backdoors to undermine cryptographic primitives. In this paper, we investigate the feasibility of algorithm substitution attacks (ASAs) on BE and formalize the corresponding adversarial model. Our findings reveal that attackers not only recover a user’s private key via public parameters but also extract a session key via any two consecutive headers, where the session key is encapsulated in the headers. Consequently, our ASAs pose a greater threat compared to previous ASAs targeting encryption primitives. To mitigate this problem, we adopt cryptographic reverse firewall (RF) as a countermeasure to achieve the security of BE against ASAs. We introduce the system model and security model of broadcast encryption with reverse firewalls (BE-RFs). Additionally, we construct an instance and provide a proof that our BE-RFs not only ensures selective identities and chosen plaintext secure (sID-CPA) but also is against ASAs. Subsequently, we implement BE-RFs on both Android devices and computers for experimental evaluations, confirming its efficacy in safeguarding security. Finally, we apply BE-RFs to data sharing in cloud storage.

Multiaccess edge computing (MEC) is a novel service paradigm located at the network’s edge, where servers with computation and storage capabilities are placed in proximity to network endpoints to meet the high-speed computation and low-latency requirements of these endpoints. MEC faces numerous security challenges, with Distributed Denial of Service (DDoS) attacks being one of the primary threats. On one hand, the edge server layer (ESL) encounters a greater number of attack sources and has relatively fewer defense resources, making traditional defense techniques less applicable. On the other hand, the ESL can integrate with new technologies for earlier detection and interception of attack traffic, achieving more real-time attack mitigation. To provide comprehensive insights into the latest research developments and inspire new DDoS defense solutions, this article conducts an extensive survey and synthesis. This article begins with a summary of the basic concepts, application scenarios, and security vulnerabilities of MEC networks. It then introduces the types and principles of DDoS attacks faced by MEC networks. Subsequently, various security solutions for DDoS attacks in MEC were detailed and extensively compared, followed by an introduction to current application cases of DDoS defense deployment in practical MEC scenarios. Finally, open issues and future research directions are listed for further exploration.

The goal of the energy internet is to enable communication between distributed energy endpoints to facilitate information exchange and trading matching. Blockchain, which ensures content consistency, bridges the gaps between multiple energy stakeholders and satisfies the need for universal trust. However, applying blockchain directly in peer-to-peer trading can result in the permanent inclusion of illegal or outdated data in blockchain databases, hindering efficient interaction. Driven by emerging application requirements and legal regulations, redactable blockchain (EuroS&P 2017) was introduced, allowing the block history to be rewritten via collisions in chameleon hash functions. Nevertheless, current solutions still face challenges, including trapdoor security risks, privacy leakage, and indefinite redactions. This paper presents a redactable energy blockchain scheme (REBS) with partially attribute-based policy hiding, which enables controlled multi-authority key generation and redactor attribute verification. To prevent the abuse of redaction permission, REBS employs time-updatable chameleon hash functions for redaction. Additionally, we design a delegation algorithm that adds dynamic flexibility to attribute verification nodes, permitting them to delegate key share distribution authority to other nodes on demand. The detailed security proofs and performance evaluations demonstrate the feasibility of REBS.

As mobile and edge devices become more prevalent, applications handling sensitive data, such as health monitoring, age verification for online services , and vulnerability scanning tools , are becoming increasingly common. The comparison of critical data (e.g., health metrics, ages, or software versions) is essential for informed decision-making. However, securely processing this sensitive information in resource-limited environments presents significant challenges. To address these challenges, we propose a server-aided secure interval test and comparison protocol based on point and range encoding. The proposed protocol allows two parties to verify if a value belongs to an interval or is less than another value without revealing their private inputs. To handle the set membership problem in the encoding, we introduce an innovative oblivious updatable key pseudorandom function. Leveraging this function, our protocol achieves efficient delegation to a cloud server, ensures that online costs grow linearly with input length, and maintains exceptionally low amortized preprocessing costs. We formally prove the semi-honest security of our protocol and compare it to the other semi-honest protocols. On the client side, our protocol requires only tens of microseconds for computational time and less than 1 KB for communication cost for inputs up to 40 bits. Compared to the other secure interval test protocols, it significantly reduces both computational and communication costs, especially for larger inputs. Moreover, it achieves the lowest computation costs while maintaining similar communication costs to the other secure comparison protocols.

The sharing of Internet of Things (IoT) data plays an extensive role in our everyday lives. Exploring secure and efficient methods for data sharing is a prominent area of research. Proxy re-encryption (PRE) in the cloud provides a solution. However, traditional PRE schemes are vulnerable to algorithm substitution attacks (ASA). Moreover, in most PRE schemes, the proxy can know the relevant identity information of the data owner or the data recipient through the re-encryption key, and some current PRE schemes cannot guarantee strong resistance to collision. To address the limitations of traditional PRE schemes and offer a robust solution for secure and efficient data sharing in IoT application, we propose a reverse firewall for proxy re-encryption (PRE-RF) scheme, which is implemented by JPBC library. Security analysis shows that our PRE-RF scheme provides effective resistance to ASA, along with strong collision security, chosen plaintext attack security, and key-private security. Compared with similar state-of-the-art PRE schemes, our scheme reduces the length of the re-encryption keys and ciphertext, thereby reducing the storage cost of the system. Meanwhile, our scheme’s computational cost is lower, thereby improving the operational efficiency of the system. Furthermore, the amount of time devoted to the reverse firewall in our scheme decreases as security level increases. As a result, these advantages make it a secure and efficient choice for sharing IoT data in unreliable cloud environments.

The Satellite-Terrestrial Integrated Network (STIN) is an emerging paradigm offering seamless network services across geographical boundaries, yet it faces significant security challenges, including limited intrusion prevention capabilities. Federated learning (FL) provides a viable solution by aggregating traffic data from STIN clients (e.g., ground stations and edge routers) to train models for network intrusion detection systems (NIDS). However, satellite and terrestrial domain data’s non-independent and identically distributed (non-IID) nature hinders training efficiency and performance. This paper proposes STINIDF, a novel STIN intrusion detection framework leveraging FL-based data augmentation. STINIDF utilizes FL to collaboratively train a conditional diffusion model across STIN nodes while preserving privacy via differential privacy mechanisms, generating global traffic data representative of the STIN distribution. Each node then integrates global and local traffic data to train a local model for NIDS, addressing non-IID challenges by balancing data distribution through data augmentation. Using a simulation environment developed with OMNeT++ and INET, a Satellite-Terrestrial Integrated (STI) traffic dataset was created, including intrusion scenarios such as signal disruption, UDP flooding, and jamming attacks. Experimental results indicate that STINIDF outperforms existing data augmentation-based approaches under non-IID conditions, achieving$\mathbf {96.63\%(2.41\%\uparrow)}$accuracy,$\mathbf {96.71\% (3.14\%\uparrow)}$precision,$\mathbf {96.54\%(1.65\%\uparrow)}$recall and$\mathbf {96.66\%(2.7\%\uparrow)}$F1 score. Furthermore, when compared to methods integrating data augmentation with differential privacy, STINIDF demonstrates an effective balance between privacy preservation and intrusion detection performance, attaining an accuracy of$\mathbf {96.14\%(2.57\%\uparrow)}$and a FID of$\mathbf {17.88(7.41\downarrow)}$.

Multimodal handwritten signatures usually involve offline images and online sequences. Since in real-world scenarios, different modalities of the same signature are generated simultaneously, most research hypothesizes that the different modalities are consistent. However, attacks launched on a partial modality (e.g., only tampering on the image modality) of signature data are commonly seen, and will cause the inter-modal inconsistency. In this paper, we propose and analyze the multimodal security and attack levels for handwritten signatures, and provide a multimodal consistency learning method to detect different levels of attacks of signatures. The modalities include not only traditional offline and online data, but also videos capturing hand movements. We collect a number of triple modal signatures to address the scarcity of public handwritten video datasets. Then, we extract hand joint sequences from videos and utilize them to analyze subtle multimodal consistency with the online modality. We provide extensive experiments for the consistency between online and offline signatures, as well as between online signatures and movement videos. The verification involves distance-based and classification-based fusion models, showing the most effective discriminative networks for attack detection and the superiority of consistency learning.

Data cleaning improves quality and consistency by detecting, localizing, and repairing “dirty” data without compromising sensitive information. Collaborative Data Cleaning employs a distributed model to avoid single points of failure and trust issues in centralized systems, although it incurs additional communication overhead. Blass et al. (S&P’23) were the first to implement CDC via balanced Private Set Intersection (PSI). Unbalanced PSI (e.g.,uPSI-CA, USENIX’23) does not address the localization of intersections within datasets and thus cannot be directly applied to CDC. uPSI-based data cleaning remains largely unexplored. In this paper, we propose an efficient CDC scheme for unbalanced datasets, nameduECDC.uECDCemploys oblivious key-value stores for slice matching, achieving: i) a reduction of 18% ~ 85% in offline phase runtime, and ii) a reduction of 8% ~ 43% in online phase runtime (under large-scale data settings on the server side), when compared to the slice-linking approach ofuPSI-CA. Moreover, we encode server-side data for fast localization of intersection data in unbalanced settings. Under the semi-honest adversary model,uECDCis provably secure. Implementation in Python and C++ demonstrates thatuECDCis practically feasible.

Recently, deep learning (DL)-driven intrusion detection technology has been rising gradually to reduce the economic and privacy losses caused by the dramatic increase in cyber attacks. Besides exploiting the statistical network traffic features, the inherent attack topologies are also important as they are highly associated with attack behaviors. Thus, many works use graph neural networks (GNN) to make use of them to improve the detection performance. Nevertheless, these topologies contain many isolated IPs that interact with far fewer targets than other non-isolated IPs. Due to the message-passing scheme, information from isolated IPs is less likely to be transmitted in GNN training, resulting in poor model understanding of the traffic connecting these isolated IPs. Therefore, the performance of GNN-based intrusion detection models is not satisfactory for this traffic. To address this problem, we implement a generation algorithm with traffic functionality preservation to improve the performance of GNN-based intrusion detectors by locally augmenting this type of traffic. The proposed method first converts the IP-based graph of the traffic dataset into a line graph, and then utilizes a conditional denoising diffusion probabilistic model to generate new graph snapshots to enhance the expressiveness of isolated IP in GNN message aggregation. We evaluate the performance of our method and compare it with state-of-the-art works on three datasets, i.e., NF-BoT-IoT-V2, NF-ToN-IoT-V2, and NF-CSECIC-IDS2018-V2, and the results show it achieves accuracy of 99.11%(↑0.11%), 93.84%(↑2.47%), and 97.15%(↑3.94%), respectively. Case study shows that the proposed local augmentation can improve detection performance under different isolated thresholds. Moreover, our method can alleviate the over-smoothing problem to a certain extent, and the augmented traffic also possesses better quality.

Internet of Things (IoT) revolutionizes data collection, especially in e-healthcare, where patients data from wearables and sensors improves medical services. However, IoT’s limitations in computing and storage require cloud outsourcing. Combining IoT with the cloud has potential but raises concerns about data security. Leveraging cloud storage presents an attractive solution for accommodating the substantial volume of data outsourced by IoT devices. As the outsourcing of real-time data to cloud storage becomes commonplace, the adoption of data auditing schemes emerges as a means to ensure data integrity. To curtail operational expenses, various deduplication techniques are commonly employed on outsourced data, effectively sidestepping redundant data and resulting in storage and bandwidth efficiencies. Although real-time data typically remains distinct due to its diverse origins, scenarios, such as data sharing or trading in data-driven services and datamarkets, can lead to data redundancy. Moreover, in order to fortify against any potential information leakage, encryption is implemented prior to deduplication. Convergent encryption (CE) stands as a prominent exemplar of this approach. Effectively integrating data auditing, deduplication, and encryption for wireless sensor devices is no trivial task. To efficiently and securely accommodate data while authenticating them through a heterogeneous framework, we present a novel remote data checking scheme, denoted as the VRDC scheme. This scheme empowers IoT data to be encrypted, updated, deduplicated, and audited, aligning with the imperatives of security, privacy, and efficiency. Through comprehensive security analysis, we establish that our VRDC scheme is fortified against potential threats. Our experimental findings highlight the efficiency of our approach in the realms of auditing, deduplication, and updates. Furthermore, the evidence highlights the potential for optimization within our scheme when compared to related works. This is achieved through the careful management of dynamic update scales within a file.

Blockchain-based authentication, as a distributed system, is a significant method to achieve secure service access and provision for the distributed mobile cloud computing (MCC) environment. However, owing to the transparency of blockchain, it remains a challenge to protect users’ access behavior from disclosure. Besides, billions of users in the MCC system may cause storage bottlenecks to the blockchain network. To overcome these challenges, this paper designs two blockchain-based privacy-preserving authentication schemes supporting hierarchical access control for the MCC environment. Both schemes allow users to access multiple services with different permissions after a single registration. To address the challenges of privacy disclosure, we use polynomial commitment to replace the plaintext on the blockchain. Meanwhile, a new verification and updating of the access permission method is proposed using the homomorphic property of polynomial commitment. The first scheme works toward reducing computation costs, which is more suitable for systems with a limited number of service providers (SPs). On the other hand, the second scheme aims to reduce the storage requirements of blockchain, and it provides more efficient hierarchical access control for large-scale scenarios without requiring more storage space. Then, the security analysis demonstrates that the two schemes satisfy multiple security requirements. Finally, a comparative summary is presented to show that our schemes have good performance in computation and communication efficiency and are well suited to the MCC system.

Keyword-based auditing (KA) provides a means for users to verify the integrity of only the outsourced data they are interested in. Existing KA schemes employ relation authentication labels to conduct targeted audits with keywords, which significantly improves the cost-effectiveness. However, such schemes typically support only a single-challenge scenario, which may not always be practical. To overcome this constraint, we introduce a hierarchical challenge mechanism grounded in user attributes. This mechanism leverages inequality and affiliation relationships to comply with a predefined tree structure for access policies. Incorporated during the challenge-response phase of the auditing model, it permits users to initiate cross-challenges. Expanding upon this hierarchical mechanism, we propose an attribute-based hierarchical keyword auditing scheme, abbreviated as$\mathcal{AHKA}$.$\mathcal{AHKA}$combines searchable encryption to conduct cross-targeted audits and benefits from the hash collision mapping of Bloom filters to safeguard against keyword guessing attacks. Moreover, we design a fault localization algorithm based on a variant of the binary search technique. It locates in batch the faulty cloud servers and damaged data blocks after an audit failure. As an integral part of$\mathcal{AHKA}$, the algorithm significantly enhances our scheme's practicability. Security analyses indicate that$\mathcal{AHKA}$can effectively withstand both forgery and replace attacks on audit proofs. The smart contract component ensures that our scheme's processes can be monitored and regulated. Experimental data corroborate that deploying$\mathcal{AHKA}$on the client side and on the blockchain is both efficient and feasible.

In order to protect data privacy in cloud storage, sensitive data is encrypted before being uploaded to a cloud server. How to retrieve ciphertext safely and effectively has become a problem. Public key encryption with keyword search (PEKS) realizes the retrieval of ciphertexts in clouds without disclosing secret information. However, most PEKS protocols can not resist an keyword guessing attack (KGA) launched by untrusted cloud servers. Meanwhile, these protocols are unable to detect vulnerabilities, resulting in information leakage. In this article, we design a searchable public-key encryption with cryptographic reverse firewalls (SPKE-CRF), and use the JPBC library to implement the protocol. Security analysis shows that the SPKE-CRF protocol can resist a chosen keyword attack (CKA), a KGA, and an algorithm substitution attack (ASA) without secure channels. Performance analysis shows that the SPKE-CRF protocol has a significant communication and computational cost advantage while being resistant to the KGA and ASA from malicious insider attackers in cloud environments. Therefore, our SPKE-CRF protocol is secure and efficient for cloud storage.

With the rapid development of Internet of Things (IoT) in recent years, the security of IoT becomes more and more prominent. To protect data privacy and device availability, identity authentication technology has been applied to the IoT environment. However, although scholars have designed a variety of authentication protocols for the IoT environment, the resource costs of these protocols are still expensive for resource-constrained devices. In particular, when the frequent upgrade of computer hardware has led to a gradual increase in the key length of the cryptosystem, IoT devices are hard to keep up with the upgrade speed because of the balance between cost and tasks. Although the storage space has increased in recent years, the computational and communication capabilities are still limited by some physical factors, such as energy, power, and communication link bandwidth. To improve the situation, this article proposes an anonymous authentication protocol suitable for IoT devices with current hardware performance, which is based on elliptic curve and signcryption techniques. Compared to other protocols, our protocol further reduces the communication and computing cost of the client devices while ensuring security requirements. Thus, we formally prove its theoretical security under the random oracle model and use simulation experiments to verify that the protocol can effectively reduce the resource requirements.

During the past few years, as Internet of Things develops rapidly, the applications of unmanned aerial vehicle (UAV) technology have been increasingly widely used. Meanwhile, the efficiency and security issues of UAV communication have brought about widespread attention of many researchers in different fields. In an open wireless network, the attacks on UAV communication mainly include eavesdropping, tampering, interrupting, forgery, etc. Signcryption is an appropriate method to address these security problems. However, the existing signcryption schemes are not suitable for UAVs with limited resources and ground station (GS) that needs to process a large number of messages from UAVs. Moreover, in a certain area, UAVs and a GS may belong to different cryptosystems. Therefore, in this article, we came up with a heterogeneous signcryption scheme for UAVs to communicate to a GS (HSC-U2G) without bilinear pairing operation, where UAVs belong to identity-based cryptography (IBC) while the GS belongs to public-key infrastructure (PKI). Moreover, our scheme provides identity privacy for UAVs and supports batch verification for the GS. Using the random oracle model, we demonstrate HSC-U2G can achieve insider security for confidentiality as well as unforgeability. After that, HSC-U2G is compared with several important related works and we provide all experimental results to show the efficiency.

In the last few years, mobile cloud computing (MCC) gains a huge development because of the popularity of mobile applications and cloud computing. User authentication and access control are two indispensable security components in the MCC environment. To the best of our knowledge, they are generally designed in different procedures. Access control can be executed after the authentication completes successfully. In order to improve efficiency, this article constructs an integrated scheme of authentication and hierarchical access control using self-certified public key cryptography (SCPKC) and the Chinese remainder theorem (CRT) for MCC environment. The proposed scheme can achieve mutual authentication while determining the access rights of mobile users without storing any access control list in the MCC service provider side. Besides, we also give a dynamic adding or deletion of MCC service provider to efficiently address potential changes in the hierarchy. The security of our proposed scheme is proved by the random oracle model. Compared with recently related multi-server authentication schemes for the MCC environment, the proposed scheme not only adds a new function of hierarchical access control but also has better computation and communication efficiencies. Therefore, the proposed scheme is more suitable for real-life MCC applications.

Deep neural networks (DNNs) can be utilized maliciously for compromising the privacy stored in electronic devices, e.g., identifying the images stored in a mobile phone connected to the Internet of Things (IoT). However, recent studies demonstrated that DNNs are vulnerable to adversarial examples, which are artificially designed perturbations in the original samples for misleading DNNs. Adversarial examples can be used to protect the DNN-based privacy leakage in mobile phones by replacing the photos with adversarial examples. To avoid affecting the normal use of photos, the adversarial examples need to be highly similar to original images. To handle a large number of photos stored in the devices at a proper time, the time efficiency of a method needs to be high enough. Previous methods cannot do well on both sides. In this article, we propose a broad class of selective gradient sign iterative algorithms to make adversarial examples useful in protecting the privacy of photos in IoT devices. By neglecting the unimportant image pixels in the iterative process of attacks according to the sort of first-order partial derivative, we control the optimization direction meticulously to reduce image distortions of adversarial examples without leveraging high time-consuming tricks. Extensive experimental results show that the proposed methods successfully fool the neural network classifiers for the image classification task with a small change in the visual effects and consume little calculating time simultaneously.

Smart grid utilizes intelligent metering and other monitoring devices that frequently collect and send a customer's usage report of energy consumption to an energy service provider (ESP). By mere behavioral inference from usage reports, its viable to adjudge the daily routine, location, and the kind of electrical devices of a customer. The collection and transmission of such data raises security concerns. Hence, its vital to secure ESP's access to a customer's data. In perspective of this, we introduce a data access control scheme which is suitable for smart grids with secure customer data access. In our scheme, the customer is a data owner while an ESP or other third party stakeholder (TPS) is the data user. A data user can have secure access to a customer's data via a gateway device such as energy service interface (ESI). The ESI fits in as proxy that re-encrypts data for authorized data users based on the delegation command from the data owner. Here, ESI is unable to acquire plaintext information on the data. Moreover, only authorized data users are eligible for decrypting and verifying the integrity and authentication of data. We achieve the data access control via a certificateless signcryption with proxy re-encryption (CLSPRE) scheme. Detailed security analysis shows that our CLSPRE scheme is secure in the random oracle model (ROM). Moreover, extensive performance evaluation indicates its efficiency with respect to communication overhead and computation complexity.

Internet of Things (IoT) is a new technology which offers enormous applications that make people’s lives more convenient and enhances cities’ development. In particular, smart healthcare applications in IoT have been receiving increasing attention for industrial and academic research. However, due to the sensitiveness of medical information, security and privacy issues in IoT healthcare systems are very important. Designing an efficient secure scheme with less computation time and energy consumption is a critical challenge in IoT healthcare systems. In this paper, a lightweight online/offline certificateless signature (L-OOCLS) is proposed, then a heterogeneous remote anonymous authentication protocol (HRAAP) is designed to enable remote wireless body area networks (WBANs) users to anonymously enjoy healthcare service based on the IoT applications. The proposed L-OOCLS scheme is proven secure in random oracle model and the proposed HRAAP can resist various types of attacks. Compared with the existing relevant schemes, the proposed HRAAP achieves less computation overhead as well as less power consumption on WBANs client. In addition, to nicely meet the application in the IoT, an application scenario is given.

Anonymous multireceiver encryption scheme can not only protect the privacy of the receiver but also ensure the security of message. However, the computational cost of this scheme is very large. It is not suitable for the sender which has limited resources, such as mobile devices and sensor nodes. In this work, an anonymous multireceiver online/offline identity‐based encryption is proposed based on offline/online and identity‐based encryption (IBE). In identity‐based encryption scheme, the sender can encrypt the message using the unique information of the user (such as identity number or e‐mail address) as its public key. The receiver obtains the private key from a central authority. For mobile device with limited resource, the online/offline encryption scheme can reduce the computational cost. Compared to the previous anonymous multireceiver schemes, the proposed scheme can efficiently encrypt message with offline/online method and ensure the anonymity of receivers. The analysis results also show that our scheme is efficient in terms of computational cost by comparing to the previous works.

The Internet of Things (IoT) is an emerging network paradigm that aims to obtain the interactions among pervasive things through heterogeneous networks. Security is an important task in the IoT. Luo et al. (Secur Commun Netw 7(10): 1560–1569, 2014 ) proposed a certificateless online/offline signcryption (COOSC) scheme for the IoT (hereafter called LTX). Unfortunately, Shi et al. showed that LTX is not secure. An adversary can easily obtain the private key of a user by a ciphertext. Recently, Li et al. proposed a new COOSC scheme (hereafter called LZZ). However, both LTX and LZZ need a point multiplication operation in the online phase, which is not suitable for resource-constrained devices. To overcome this weakness, we propose a new COOSC scheme and prove its security in the random oracle model. In addition, we analyze the performance of our scheme and show its application in the IoT.

Wireless sensor network (WSN) plays an important role in military sensing and tracking, target tracking, and environment monitoring. To query of the network to get useful information from anywhere and anytime, we need to integrate the WSN into the Internet as part of the Internet of Things (IoT). In this case, it is an important task to design an access control scheme that can authorize, authenticate and revoke a user to access the WSN. In this paper, we propose a heterogeneous signcryption scheme to control the access behavior of the users. We give the formal security proof of our scheme in the random oracle model. An important characteristic of our scheme is to allow a user in a certificateless cryptography (CLC) environment to send a message to a sensor node in an identity-based cryptography (IBC) environment. We give an access control scheme for the WSN in the context of the IoT using the proposed signcryption scheme. As compared with existing two access control schemes using signcryption, the computational cost of sensors in our scheme is reduced by about 22% and 53%, respectively and the energy consumption of sensors in our scheme is reduced by about 33% and 54%, respectively.

Abstract Outsourcing decryption that enables the authorized users to obtain the original data without decryption computation is crucially important for wireless sensor networks in public data center. The existing outsourcing decryption schemes have been designed based on key‐policy attribute‐based encryption. The security of outsourcing decryption cannot be guaranteed, because the data center is not loyal, and existing schemes have high computational complexity and energy consumption. In this work, a novel partially outsourcing decryption scheme is proposed to guarantee data security and computational efficiency for resource‐constrained sensor nodes and terminal equipments. According to the attributes of cluster nodes in the proposed scheme, the encryption secret key is encrypted based on group key‐policy attribute‐based encryption and sent to data center, and authorized users who satisfy the attributes of the ciphertext can obtain the secret key to decrypt the ciphertext. Furthermore, in order to reduce the decryption overhead for users, the authorized users can simply decrypt the transformation ciphertext that is partially decrypted by the data center using token key. Compared with the previous decryption schemes, the proposed scheme efficiently decrypts ciphertext and enhances security of the data. The simulation results also indicate that the proposed scheme is efficient in terms of energy consumption and computation by comparing to previous work. Copyright © 2016 John Wiley & Sons, Ltd.

Confidentiality and authentication are two main security goals in secure electronic mail (e-mail). Pretty good privacy (PGP) and secure/multipurpose internet mail extensions (S/MIME) are two famous secure e-mail solutions. Both PGP and S/MIME use digital envelope to provide message confidentiality and digital signature to provide message authentication. However, these methods have the following two weaknesses: 1) digital signature provides non-repudiation evidence of sender that is not desired in some e-mail applications and 2) efficiency is low, since these methods use two kinds of public key cryptographic primitives: public key encryption and digital signature. To overcome the above two weaknesses, we introduce a new concept called deniably authenticated encryption that can achieve confidentiality, integrity, and deniable authentication in a logical single step. We first propose a deniably authenticated encryption scheme and prove its security in the random oracle model. Then, we design a secure e-mail protocol using the proposed deniably authenticated encryption scheme. The deniable authentication property protects senders' privacy.

BACKGROUND: Amplicon re-sequencing based on the automated Sanger method remains popular for detection of single nucleotide polymorphisms (SNPs) and insertion-deletion polymorphisms (InDels) for a spectrum of genetics applications. However, existing software tools for detecting intra-individual SNPs and InDels in direct amplicon sequencing of diploid samples are insufficient in analyzing single traces and their accuracy is still limited. RESULTS: We developed a novel computation tool, named DiSNPindel, to improve the detection of intra-individual SNPs and InDels in direct amplicon sequencing of a diploid. Neither reference sequence nor additional sample was required. Using two real datasets, we demonstrated the usefulness of DiSNPindel in its ability to improve largely the true SNP and InDel discovery rates and reduce largely the missed and false positive rates as compared with existing detection methods. CONCLUSIONS: The software DiSNPindel presented here provides an efficient tool for intra-individual SNP and InDel detection in diploid amplicon sequencing. It will also be useful for identification of DNA variations in expressed sequence tag (EST) re-sequencing.

Signcryption schemes play a vital role to accomplish confidentiality, integrity, authentication and non-repudiation of messages simultaneously. In the literature, many certificateless signcryption (CLSC) schemes have been designed; however, most of them are vulnerable to ephemeral secret leakage (ESL) attack. In these schemes, sender uses an ephemeral secret to compute a ciphertext on a message. However, there is a possibility to compromise the ephemeral secret, since it is generally pre-computed and stored in an insecure device. Furthermore, it is generated by an external source, which can be controlled by an adversary. Thus, from the knowledge of compromised ephemeral secret, an adversary may calculate the private key of the sender and the message from the eavesdropped ciphertext, and this problem is called ESL attack. In this paper, we proposed a leakage-free CLSC, which is secure against ESL attack in the random oracle model. The proposed scheme provides confidentiality under the Co-Bilinear Diffie–Hellman (Co-BDH) assumption and unforgeability based on Co-Computational Diffie–Hellman assumption.

SUMMARY Signcryption is a cryptographic primitive that performs simultaneously both the functions of digital signature and public‐key encryption, at a cost significantly lower than that required by the traditional signature‐ then‐encryption approach. In this paper, we provide a positive answer to the question of if it is possible to construct signcryption based on lattice problems. More precisely, we design an efficient signcryption scheme that can send a message of length l one time. We prove that the proposed scheme has the indistinguishability against adaptive chosen ciphertext attacks under the learning with errors assumption and strong unforgeability against adaptive chosen messages attacks under the inhomogeneous small integer solution assumption in the random oracle model. Copyright © 2012 John Wiley & Sons, Ltd.

ABSTRACT An identity‐based signature scheme from lattices is constructed. The scheme is obtained from a modification of Agrawal, Boneh, and Boyen's lattice identity‐based encryption scheme. In this construction, we use two distinct trapdoors for finding short bases. One trapdoor enables the real implementation to generate short bases for all lattices. The other trapdoor enables the simulator to generate short bases for all lattices. Furthermore, the generating short bases are used to sample short vectors as signatures. Our scheme is computationally efficient. The scheme's strong unforgeability is proven in the standard model and rests on the hardness of the small integer solution problem. Finally, we extend the basic construction to obtain a hierarchical identity‐based signature scheme. Copyright © 2012 John Wiley & Sons, Ltd.

SUMMARY Signcryption is a cryptographic primitive that fulfills both the functions of digital signature and public key encryption simultaneously, at a cost significantly lower than that required by the traditional signature‐then‐encryption approach. The performance advantage of signcryption over the signature‐then‐encryption method makes signcryption useful in many applications, such as electronic commerce, mobile communications, and smart cards. In this paper, we propose an efficient signcryption scheme in the standard model. We prove that our scheme satisfies the confidentiality and strong unforgeability. Compared with the Tan's scheme, our scheme has | G | + | p | (320) bits shorter ciphertext, 2 | p | − | G | (160) bits shorter private key, and | GT | + | G | (1184) bits shorter public key. In addition, in the Tan's scheme, a user must hold two public key/private key pairs at one time if it were both sender and receiver. Our scheme only needs a public key/private key pair, which is more practical for application. Copyright © 2011 John Wiley & Sons, Ltd.

ABSTRACT In this paper, we introduce an efficient and trustworthy conditional privacy‐preserving communication protocol for VANETs based on proxy re‐signature. The proposed protocol is characterized by the trusted authority (TA) designating the roadside units to translate signatures computed by the on‐board units into one that are valid with respect to TA's public key. In addition, the proposed protocol offers both a priori and a posteriori countermeasures: it can not only provide fast anonymous authentication and privacy tracking, but also guarantee message trustworthiness for vehicle‐to‐vehicle communications. Furthermore, it reduces the communication overhead and offers fast message authentication and low storage requirements. We use extensive analysis to demonstrate the merits of the proposed protocol and to contrast it with previously proposed solutions. Copyright © 2012 John Wiley & Sons, Ltd.

Signcryption is a cryptographic primitive that performs digital signature and public key encryption simultaneously, at lower computational costs and communication overhead than signing and encrypting separately. Recently, Yu et al. proposed an identity based signcryption scheme with a claimed proof of security. We show that their scheme is not secure even against a chosen-plaintext attack.

Signcryption is a cryptographic primitive that fulfills both the functions of digital signature and public key encryption simultaneously, at a cost significantly lower than that required by the traditional signature-then-encryption approach. In this paper, we address a question whether it is possible to construct a hybrid signcryption scheme in identity-based setting. This question seems to have never been addressed in the literature. We answer the question positively in this paper. In particular, we extend the concept of signcryption key encapsulation mechanism to the identity-based setting. We show that an identity-based signcryption scheme can be constructed by combining an identity-based signcryption key encapsulation mechanism with a data encapsulation mechanism. We also give an example of identity-based signcryption key encapsulation mechanism.

A new concept called multi-proxy multi-signcryption is introduced in this paper. In a multi-proxy multi-signcryption scheme, a group of original signcrypters can authorize a group of proxy signcrypters under the agreement of all signcrypters in the original group. Then only the cooperation of all signcrypters in the proxy group could generate a multi-proxy multi-signcryption. We propose a multi-proxy multi-signcryption scheme based on bilinear pairings. The proposed scheme has the following characteristics: (i) the size of multi-proxy multi-signcryption is independent of the number of original and proxy signcrypters. (ii) it provides the fair protection for the original signcrypter group and the proxy group.(iii) the key management problem is simplified because of using ID-based cryptography. Finally, we give an application of the proposed scheme in electronic commerce.

A deniable authentication allows the receiver to identify the source of the received messages but cannot prove it to any third party. However, the deniability of the content, which is called restricted deniability in this paper, is concerned in electronic voting and some other similar application. At present, most non-interactive deniable authentication protocols cannot resist weaken key-compromise impersonation (W-KCI) attack. To settle this problem, a non-interactive identity-based restricted deniable authentication protocol is proposed. It not only can resist W-KCI attack but also has the properties of communication flexibility. It meets the security requirements such as correctness, restricted deniability as well. Therefore, this protocol can be applied in electronic voting.