Summary The present scenario witnesses “the second quantum revolution,” which has enabled the development of revolutionary novel quantum tools. Quantum computing endeavors to establish higher computing standards that can potentially solve complex structures. Post‐quantum cryptography (PQC) has emerged as one of the new domains of cryptography, which is resilient to quantum attacks owing to the revolution in quantum computing. To ensure quantum security, the lattice‐based cryptosystem (LB‐cryptosystem) is one of the promising tools of PQC to address quantum‐based threats. The traditional security algorithms, such as RSA and Diffie–Hellman (DH), are strong enough to resist present security threats. However, it has been predicted that quantum technologies have the capability to break the security of most traditional algorithms whose security is based on prime factorization and DH‐type hard problems. Therefore, research is currently focused on addressing the security and privacy threats by using LB‐cryptosystems to secure various applications, organizations' data, and information infrastructure in the quantum era. The purpose of this article is to investigate recent advances in LB‐cryptosystems that may allow the design of secure models for smart‐grid networks (SGNs) against existing and future quantum attacks. SGNs have been explored as the bi‐directional assimilation of communication in terms of electricity generation, transmission, allocation, and utilization. This survey provides a comprehensive overview of LB‐cryptosystems, as well as their potential applications in securing SGNs. Lastly, the article summarizes the various PQC primitives, NIST selected algorithms, open‐source tools along with their packages, and various PQC industrial initiatives, and also compares traditional cryptographic schemes with other PQC.

The Internet of Things (IoT) is an emerging technology that has become popular in many applications, such as transportation, agriculture, healthcare, industrial automation, robotics, etc. IoT devices are interconnected via the Internet, and secure message communication between them is a challenging task. An authenticated key agreement (AKA) protocol can solve such an issue. This article designed and implemented an identity-based three-party AKA (IoT-ID3PAKA) protocol to establish a shared session key among three IoT devices. The current state-of-the-art identity-based 3PAKA (ID-3PAKA) protocols are unsuitable for resource-constrained IoT devices because almost all of them undergo various security attacks and require higher execution and communication overheads. The provable security of the proposed IoT-ID3PAKA protocol relies on the hardness assumption of the elliptic curve-based computational Diffie–Hellman problem. The execution time of IoT-ID3PAKA for the security levels: 80, 112, 128, 192, and 256 bits on a Raspberry Pi 4 device is estimated and compared with the existing ID-3PAKA protocols.

Abstract The smart healthcare system (SHS), a significant medical domain underpinning the Internet of Things (IoT), which collects and analyzes health data from many sources to provide better medical treatment. The smart healthcare system is a combination of hardware and software used in the medical care field, providing remote diagnosis and treatment via a patient‐based health data‐sharing system. To increase security, a large variety of authenticated techniques have been developed over the past several decades, most of which are based on conventional number‐theoretic assumptions such as discrete logarithms and integer factorization problems. However, Shor's method is capable of solving number‐theory‐based problems. As a result, Shor's technique might be used to resolve challenging number theory problems on a quantum computer effectively. Therefore, this article presents blockchain‐based healthcare record solutions with lattice RLWE‐based key exchange protocol using a smart card. Blockchain applications may correctly detect errors, including those that are risky, in the medical industry. It can also improve the efficiency, security, and transparency of transferring medical data throughout the healthcare protocol. The formal security of this protocol is shown under the ROM (random oracle model), and the informal security is also given in this article against well‐known attacks. The presented protocol outperforms related earlier mechanisms in terms of communication and computational cost overheads, according to the performance study.

This paper presents a new homomorphic public-key encryption scheme based on the elliptic curve cryptography (HPKE-ECC). This HPKE-ECC scheme allows public computation on encrypted data stored on a cloud in such a manner that the output of this computation gives a valid encryption of some operations (addition/multiplication) on original data. The cloud system (server) has only access to the encrypted files of an authenticated end-user stored in it and can only do computation on these stored files according to the request of an end-user (client). The implementation of proposed HPKE-ECC protocol uses the properties of elliptic curve operations as well as bilinear pairing property on groups and the implementation is done by Weil and Tate pairing. The security of proposed encryption technique depends on the hardness of ECDLP and BDHP.