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In principle, every linear code can be used to construct a secret sharing scheme. However, determining the access structure of the scheme is a very difficult problem. In this paper, we study MacDonald codes over the finite non-chain ring ${\mathbb{F}}_p+v{\mathbb{F}}_p$, where p is a prime and $v^2=v$. We provide a method to construct a class of two-weight linear codes over the ring. Then, we determine the access structure of secret sharing schemes based on these codes.

Internet of Things (IoT) is a modern technology that is applicable almost everywhere nowadays. Everything is connected to the Internet in the modern digital era. IoT is a collection of things that are interconnected to share information. Devices connected to IoT networks have some limitations in performing heavy computational tasks because of the availability of less computational and battery power. Attribute Based Encryption (ABE) is a modern public-key cryptographic technique that provides privacy with access control. The bilinear map is an expensive operation that is used in most of the ABE schemes. Elliptic Curve Cryptography (ECC) is an alternative for bilinear pairing to reduce the computation of encryption and decryption in ABE schemes.

The process of encryption and decryption of ABE is a heavy computational task for resource-constrained devices. In this paper, an outsourcing-based decryption of ABE using ECC is proposed to reduce the decryption overhead of devices that have limited computational resources. Our scheme divides the computation of the decryption of ABE into two stages: first, the partial decryption of ciphertext in the cloud server, and second, the final decryption of partially decrypted ciphertext by the data user to retrieve the original message. This scheme is secure against the malicious cloud server by adding a blinding factor into the secret to be shared. The blinding factor is shared with intended users through attribute authority. The experimental results demonstrate that our scheme can reduce the decryption complexity and save the computational time of devices, compared to the existing schemes. Thus the proposed scheme is applicable for lightweight devices used in IoT.

Quantum secret sharing (QSS) is a fundamental primitive in quantum cryptography. The existing QSS protocols are either $(n,n)$-threshold or $(t,n)$-threshold access structure, where $n$ denotes the number of players and $t$ denotes the threshold number of players. Here, we introduce a novel verifiable QSS scheme that executes a restricted hyperstar access structure by using entangled states. Our method involves encoding selected quantum states and their corresponding measurements to yield outcomes of either $+1$ or $-1$. Furthermore, we give the validation of the scheme through the system of equations derived from the measurements, which then guarantees the honesty of the participants. At last, we also analyze the security of our scheme in two primary quantum attacks, such as external attacks and internal attacks.

The Internet of Things (IoT) is a new technology that has drawn interest from both industry and academia in the modern digital era. The IoT provides a platform for any device to connect and share data over the Internet. Because of the diverse IoT environment and resource-constrained IoT devices, this nascent technology has numerous security challenges. Due to the lack of fine-grained access control and flexibility, traditional cryptographic algorithms such as private key encryption and public-key encryption are not suitable for providing access control mechanisms. ABE (Attribute-Based Encryption) is a new cryptographic approach that not only provides security but also fine-grained access control. This paper provides a comprehensive survey of ABE and its various forms, such as key policy ABE and ciphertext policy ABE, based on access structure, multi-authority, and hierarchy features. Further access structures used in ABE and applications of the ABE technique in IoT are also discussed. A comparison of different ABE schemes is presented regarding features, efficiency, and security. In addition, numerous schemes are analyzed to uncover obstacles, issues, and gaps that need to be investigated further.

This paper serves as an introduction to secret sharing scheme, and it provides the fundamental understandings to the scheme from various aspects. We first review the basics of a Shamir threshold scheme, and discuss various enhancements so that the scheme can be proactive and verifiable. We then show how a Shamir scheme can be extended to realize any general access structure. We also point out the relationship between a Shamir scheme and other topics such as error correction code, ramp scheme, information disposal algorithm and multiparty computation. Finally, we briefly discuss other platforms for its implementation.