It is widely believed that hyper elliptic curve cryptosystems (HECCs) are not attractive for wireless sensor network because of their complexity compared with systems based on lower genera, especially elliptic curves. Our contribution shows that for low cost security applications HECs cryptosystems can outperform elliptic curve cryptosystems. The aim of this paper is to propose a discrete logarithm problem-based lightweight secure communication system using HEC. We propose this for different genus curves over varied prime fields performing a full scale study of their adaptability to various types of constrained networks. Also, we propose to evaluate the performance of the protocol for computational times with respect to different genus for main operations like Jacobian, Divisor identifications, key generation, signature generation/verification, message encryption, and decryption by changing the size of the field. A formal security model was established based on the hardness of HEC-Decision Diffie-Hellman (HEC-DDH). Finally, a comparative analysis with ECC-based cryptosystems was made, and satisfactory results were obtained. KEYWORDSDiffie-Hellman, elliptic curve, genus, hyper elliptic curve, Jacobian, wireless sensor networks | INTRODUCTIONIn modern world, most of the wireless systems require resource constrained devices such as RFID tags, sensors, smart cards, small processors, PDA's, and smart phones. These devices play a major role in providing security for satellite communication, internet security, e-banking, e-commerce, Internet Of Things (IOT) applications, and embedded systems. Implementing security for wireless communication system using these devices is the most challenging problem. Many cryptographic algorithms were developed to accomplish their requirements for secure data communication in wireless systems. These algorithms have many limitations, which include increased power consumption, communication, and computational complexity with increased processing time. Thus, an efficient cryptographic algorithm that overcomes these limitations is the need of the hour.Public key cryptography (PKC) 1 offers a solution to the above limitations by using 2 different keys known as the public and private keys. The secret (private) key is chosen by the user and is well known only to him. The public key is computed from the private key by using a reversible mathematical process and is made open to all. Both the keys are interoperable on each other and are used for the decryption and encryption processes. As the private key is never revealed, PKC is highly secured unlike symmetric key cryptography. Based on the arithmetic operations, PKC is broadly

This paper proposes a new two round authenticated contributory group key agreement (ACGKA) protocol based on elliptic curve Diffie-Hellman (ECDH) with integrated signature. In this technique, one node is picked up as the group controller, and this node runs an authenticated ECDH with the rest of the nodes to generate an authenticated shared key per each twoparty. It then merges these keys in another round in such a way that every member obtains the identical authenticated group key. Further, ACGKA is extended to dynamic ACGKA protocol. The dynamic ACGKA, being elliptic curve decisional Diffie Hellman-based, is less expensive and well suited for resource constrained networks such as mobile ad-hoc networks, and wireless sensor network. Also, we demonstrate that all the protocols proposed in this paper are provably secure in the standard model under ECDDH assumption and moreover secure against most of the active and passive attacks. Finally, the proposed protocol is compared with other prevalent ECDH and Diffie Hellman based group key agreement protocols, and results are found to be satisfactory. The simplicity and the elegance of the two-party D-H key agreement [13] motivated many researcher to extend D-H to group settings. Most of the GKA protocols are discrete logarithm problem (DLP) based. However, larger key lengths and heavier computational loads are very much critical for ad-hoc networks. The logical solution to this end is to employ elliptic curve cryptography [14,15], because it can provide high security with smaller key sizes, lesser computational expenses, and greater efficiency. In view of the aforementioned qualities elliptic curve discrete logarithm problem (ECDLP) based key agreement protocols are a natural solution to resource constrained networks such as mobile ad-hoc networks (MANETS) and wireless secure network (WSN). Apart from authentication, the dynamic nature of the protocol, namely, refreshing of GK as soon as members join and/or leave the group is now an integral part of several of these protocol investigations as else the

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With the rapid increase in the popularity of groupware applications whose security mainly relied on the key being used, which made multi‐party/group secret key agreements significant. However, the brute‐force attacks to interpret the group key made group communication vulnerable. The logical solution to overcome this is changing the group key frequently. In this direction, we propose blockchain‐based multiple shared keys agreement among a group of participants. As with conventional methods, the proposed protocol does not rely on strong random number generation and/or master key. In this technique, the privacy‐preserving smart contract acts as group controller (GC) and forms two parties with each of the other nodes. The GC, while generating these two‐party keys in the first round instead of exchanging one public key, it exchanges “m” public keys with each of the other nodes and generates m2 shared two‐party keys with each of the respective nodes. Now in the second round, GC generates m2 sequential products of two‐party shared keys and stores them securely as private data objects in the privacy‐preserving smart contract. Next GC computes m2sequential public keys to each of the respective nodes by multiplying these products with the inverse of individual members shared keys sequentially of the group nodes in trusted execution environment and shares them with respective group nodes. On receiving respective public keys, each group node computes the multiple multiparty shared keys by multiplying it with their individual shared keys. Furthermore, an upper limit for the number of shared keys obtained in terms of the number of keys exchanged.

Multi-Agent Systems can support e-Healthcare applications for improving quality of life of citizens. In this direction, we propose a healthcare system architecture named smart healthcare city. First, we divide a given city into various zones and then we propose a zonal level three-layered system architecture. Further, for effectiveness we introduce a Multi-Agent System (MAS) in this three-layered architecture. Protecting sensitive health information of citizens is a major security concern. Group key agreement (GKA) is the corner stone for securely sharing the healthcare data among the healthcare stakeholders of the city. For establishing GKA, many efficient cryptosystems are available in the classical field. However, they are yet dependent on the supposition that some computational problems are infeasible. In light of quantum mechanics, a new field emerges to share a secret key among two or more members. The unbreakable and highly secure features of key agreement based on fundamental laws of physics allow us to propose a Quantum GKA (QGKA) technique based on renowned Quantum Diffie–Hellman (QDH). In this, a node acts as a Group Controller (GC) and forms 2-party groups with remaining nodes, establishing a QDH-style shared key per each two-party. It then joins these keys into a single group key by means of a XOR-operation, acting as a usual group node. Furthermore, we extend the QGKA to Dynamic QGKA (DQGKA) by adding join and leave protocol. Our protocol performance was compared with existing QGKA protocols in terms of Qubit efficiency (QE), unitary operation (UO), unitary operation efficiency (UOE), key consistency check (KCC), security against participants attack (SAP) and satisfactory results were obtained. The security analysis of the proposed technique is based on unconditional security of QDH. Moreover, it is secured against internal and external attack. In this way, e-healthcare Multi-Agent System can be robust against future quantum-based attacks.