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

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

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

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

Antimicrobial activity study of ethanolic extract of Alternanthera sessilis linn. aerial parts

The ethanolic extract of Alternanthera sessilis Linn. was evaluated for antimicrobial activity study against medically important gram-positive bacteria such as Staphylococcus aureus, Bacillus subtilis, Bacillus polymexia & Streotococcus faecalis, gram negative bacteria such as Pseudomonas aerugenosa, Salmonella typhii, Shigella dysenteriae & Escherichia coli and fungi like Penicillum notatum, Aspergillus niger & Candida albicans. The in-vitro antimicrobial activity, minimum inhibitory concentration (MIC) of ethanolic extract was performed by broth dilution method and the zone of inhibition was studied by agar disc diffusion method at concentrations of 2, 5 and 10mg/ml in DMSO. Ciprofloxacin (5µg/ml) and Cotrimazole (25µg/ml) were used as reference control for the antibacterial and antifungal studies respectively. The results of MIC study revealed the antimicrobial activity of the extract against the tested strains of microorganisms between concentration range of 50 and 400 µg/ml. The results of zone of inhibition study revealed concentration dependant nature of the extract with better effectiveness against gram-positive bacteria than gram-negative bacteria. The present study indicates the potential usefulness of Alternanthera sessilis Linn. aerial parts in the treatment of various pathogenic diseases as mentioned in the ayurvedic literature

On the Security of `An Efficient Biometric Authentication Protocol for Wireless Sensor Networks\u27

In 2013, Althobaiti et al. proposed an efficient biometric-based user authentication scheme for wireless sensor networks. We analyze their scheme for the security against known attacks. Though their scheme is efficient in computation, in this paper we show that their scheme has some security pitfalls such as (1) it is not resilient against node capture attack, (2) it is insecure against impersonation attack and (3) it is insecure against man-in-the-middle attack. Finally, we give some pointers for improving their scheme so that the designed scheme needs to be secure against various known attacks