A Key Establishment Scheme for Mobile Wireless Sensor Networks Using Post-Deployment Knowledge

Establishment of pairwise keys between sensor nodes in a sensor network is a difficult problem due to resource limitations of sensor nodes as well as vulnerability to physical captures of sensor nodes by the enemy. Public-key cryptosystems are not much suited for most resource-constrained sensor networks. Recently, elliptic curve cryptographic techniques show that public key cryptosystem is also feasible for resource-constrained sensor networks. However, most researchers accept that the symmetric key cryptosystems are viable options for resource-constrained sensor networks. In this paper, we first develop a basic principle to address the key pre-distribution problem in mobile sensor networks. Then, using this developed basic principle, we propose a scheme which takes the advantage of the post-deployment knowledge. Our scheme is a modified version of the key prioritization technique proposed by Liu and Ning. Our improved scheme provides reasonable network connectivity and security. Moreover, the proposed scheme works for any deployment topology.Comment: Published in International Journal of Computer Networks & Communications (IJCNC) Vol.3, No.4, July 201

An Identity Based Key Management Scheme in Wireless Sensor Networks

Pairwise key establishment is one of the fundamental security services in sensor networks which enables sensor nodes in a sensor network to communicate securely with each other using cryptographic techniques. It is not feasible to apply traditional public key management techniques in resource-constrained sensor nodes, and also because the sensor nodes are vulnerable to physical capture. In this paper, we introduce a new scheme called the identity based key pre-distribution using a pseudo random function (IBPRF), which has better trade-off between communication overhead, network connectivity and resilience against node capture compared to the other key pre-distribution schemes. Our scheme can be easily adapted in mobile sensor networks. This scheme supports the addition of new sensor nodes after the initial deployment and also works for any deployment topology. In addition, we propose an improved version of our scheme to support large sensor networks.Comment: 7 pages, Published in Proceedings of 4th Asian International Mobile Computing Conference (AMOC 2006), Kolkata, India, pp. 70-76, January 4-7, 200

Bipartite powers of some classes of bipartite graphs

Graph powers are a well-studied concept in graph theory. Analogous to graph powers, Chandran et al.[3] introduced the concept of bipartite powers for bipartite graphs. In this paper, we will demonstrate that some well-known classes of bipartite graphs, namely the interval bigraphs, proper interval bigraphs, and bigraphs of Ferrers dimension 2, are closed under the operation of taking bipartite powers. Finally, we define strongly closed property for bipartite graphs under powers and have shown that the class of chordal bipartite graphs is strongly closed under powers

Phyto-pharmacological review of Portulaca quadrifida Linn.

Portulaca quadrifida Linn. (Family: Portuleacea), commonly known as “Chicken Weed”, a traditional medicinal plant has been used in the Ayurvedic system of medicine for centuries, valued for its benefits in the management of urinary and inflammatory disorders. The juice of leaves is applied to abscesses and decoction is given in dysentery. The decoction of the plant can act as anthelminthic and used in the treatment of stomach complaints and gonorrhoea. Portulaca quadrifida has been reported to possess antifungal activity. The effect of ethanolic extract of Portulaca quadrifida on central and peripheral nervous system were studied by using spontaneous motor activity, in vivo muscle relaxant activity (Grip strength) and anticonvulsant activity and it is also found to have good effect on central nervous system. In this review, we have explored the Phyto-pharmacological properties of the Portulaca quadrifida plant and compiled its vast pharmacological applications to comprehend and synthesize the subject of its potential image of multipurpose medicinal agents

Obstruction characterization of co-TT graphs

Threshold tolerance graphs and their complement graphs ( known as co-TT graphs) were introduced by Monma, Reed and Trotter[24]. Introducing the concept of negative interval Hell et al.[19] defined signed-interval bigraphs/digraphs and have shown that they are equivalent to several seemingly different classes of bigraphs/digraphs. They have also shown that co-TT graphs are equivalent to symmetric signed-interval digraphs. In this paper we characterize signed-interval bigraphs and signed-interval graphs respectively in terms of their biadjacency matrices and adjacency matrices. Finally, based on the geometric representation of signed-interval graphs we have setteled the open problem of forbidden induced subgraph characterization of co-TT graphs posed by Monma, Reed and Trotter in the same paper.Comment: arXiv admin note: substantial text overlap with arXiv:2206.0591

Undeniable Authentication of Digital Twin-managed Smart Microfactory

Smart Microfactories Use Additive Manufacturing to Create Products with Mixed Materials and Variable Sizes. Digital Twin Technology Enhances Control of the Additive Manufacturing Equipment in These Factories, Increasing Productivity and Minimizing Errors. the Digital Twins Communicate with the Machines to Furnish Sensitive Data and Instructions, Which Must Be Protected from Tampering. Authentication Rescues the Digital and Physical Twins from Menacing Attacks Such as Privileged Insider, Impersonation, Ephemeral Secret Leakage (ESL) and Man-In-The-Middle (MiTM) Attacks. to This End, We Propose Lightweight Authentication among the Digital and Physical Twins with the Undeniability of Issued Commands and Deniable Key Agreement. It Achieves Perfect Forward Secrecy, Unforgeability and Anonymity. Rigorous Formal Verification with AVISPA and Informal Security Analysis Show the Robustness of This Protocol to the Aforesaid Attacks

Jahn-Tellerovi efekti u bakarnom fluor-silicij heksahidratu s 10% cinka: EPR mjerenja u X-pojasu

Stable crystals of copper fluosilicate hexahydrate (CZFH) have been successfully grown. X-band (9 GHz) EPR spectral studies carried out at room and liquid nitrogen temperatures have revealed some new features of Jahn-Teller effect in CZFH.Uspješno smo pripremili stabilne kristale bakarnog fluor-silicij heksahidrata (CZFH). Načinili smo mjerenja EPR spektara u X-pojasu (9 GHz) na sobnoj temperaturi i temperaturi tekućeg dušika koja pokazuju neke nove odlike JahnTellerovog efekta u CZFH