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With the rise of cloud computing, multi-user scenarios have become a common setting for data sharing nowadays. The conservative security notion might not be sufficient for such a data sharing model. As a response to this challenge, there has been significant research targeting security against receiver selective-opening (RSO) attacks. However, we found that none of these studies discuss RSO security specifically for predicate encryption (PE)—an encryption mechanism naturally designed for multi-user data sharing. This manuscript first formalizes the RSO security for PE. We then present a generic PE construction that achieves RSO security based on the simulation-based definition. Our work also features several instantiations for various predicate families, including attribute-based encryption for the monotone span program, which is known as one of the most expressive PE. [ABSTRACT FROM AUTHOR]

The industrial Internet of Things (IIoT) integrates sensors, instruments, equipment and industrial applications, enabling traditional industries to automate and intelligently process data. To reduce the cost and demand of required service equipment, IIoT relies on cloud computing to further process and store data. Public-key encryption with keyword search (PEKS) plays an important role, due to its search functionality, to ensure the privacy and confidentiality of the outsourced data and the maintenance of flexibility in the use of the data. Recently, Huang and Li proposed the 'public-key authenticated encryption with keyword search' (PAEKS) to avoid the insider keyword guessing attacks (IKGAs) in the previous PEKS schemes. However, all current PAEKS schemes are based on the discrete logarithm assumption and are therefore vulnerable to quantum attacks. In this study, we first introduce a generic PAEKS construction, with the assistance of a trusted authority, that enjoys the security against IKGA in the standard model, if all building blocks are secure under standard model. Based on the framework, we further propose a novel instantiation of quantum-resistant PAEKS that is based on NTRU assumption under random oracle. Compared with its state-of-the-art counterparts, the experiment result indicates that our instantiation is more efficient and secure. [ABSTRACT FROM AUTHOR]

In the era of cloud computing, massive quantities of data are encrypted and uploaded to the cloud to realize a variety of applications and services while protecting user confidentiality. Accordingly, the formulation of methods for efficiently searching encrypted data has become a critical problem. Public-key encryption with keyword search is an efficient solution that allows the data owner to generate encrypted keywords for a given document while also allowing the data user to generate the corresponding trapdoor for searching. Huang and Li proposed a public-key authenticated encryption with keyword search (PAEKS) scheme to resist keyword guessing attacks, where the data owner not only encrypts keywords but also authenticates them. However, existing PAEKS-related schemes carry a tradeoff between efficiency, storage cost, and security. In this article, we introduce a novel framework called identity-certifying authority-aided identity-based searchable encryption, which has the advantage of reducing storage space while remaining the efficiency and security. We formally define the system model and desired security requirements to represent attacks in a real scenario. In addition, we propose a provably secure scheme based on the gap bilinear Diffie–Hellman assumption and experimentally evaluate our scheme in terms of its performance and theoretical features against its state-of-the-art counterparts. [ABSTRACT FROM AUTHOR]

Cloud-based data sharing systems (DSS) have become prevalent due to their ample storage and convenient access control. To protect sensitive data privacy in DSS, anonymous identity-based encryption (IBE) is a promising approach, enabling encryption using a recipient's identity as a public key, while preventing identity and data leaks out of ciphertexts. As complete anonymity risks abuse and illegal usage, Blazy et al. introduced the notion called anonymous IBE with traceable identities (AIBET) at ARES'19, allowing users with tracing keys to identify recipients from ciphertexts. Unfortunately, existing AIBET schemes lack tracing key delegation and only consider security in weaker models (i.e., selective-identity attacks and chosen-plaintext attacks), posing risks of inconvenience and user privacy leaks. In this paper, we introduce a novel notion called anonymous hierarchical identity-based encryption with delegated traceability (AHIBEDT) for DSS. We formalize its syntax and define security notions in stronger models (i.e., adaptive-identity attacks and chosen-ciphertext attacks). In addition, we demonstrate that a concrete AHIBEDT scheme can be simply obtained from a hierarchical IBE scheme and a one-time signature scheme. The comparison results indicate that, despite a substantial increase in communication and computational costs, our approach achieves better security and functionality. • We formalize the definition and security models for AHIBEDT. • We present a generic construction of AHIBEDT by leveraging anonymous HIBE and OTS. • We show that the proposed construction satisfies anonymity and indistinguishability. [ABSTRACT FROM AUTHOR]