Secure kNN Query Processing in Untrusted Cloud Environments: an Overview

ABSTRACT: Nowadays, data are stored to a third party in cloud environments and query processing is also done by the third party to reduce the expense to maintain the system. Although there are lots of advantages in using independent third parties in query processing, security problems become more crucial since we cannot completely trust the third parties which can be easily corrupted or malfunctioning. The security problems with untrusted third parties are multifaceted in several areas such as privacy, authentication, and recovery. For privacy, the third party should not be able to know what the user's query is since the query itself describes the user's interest. For authentication, the user should be able to verify that the information from the third party is not tampered since the correctness of the query results depends upon the correctness of the information from the third party. For recovery, when the result is found to be forged by an adversary, we should be able to find the adversary and get a correct result by removing the adversary. To address these challenges, we propose several schemes. First, with respect to secure kNN query processing and secure proximity detection, we give novel schemes based on Mutable Order Preserving Encryption (MOPE) and Secure Point Evaluation Method (SPEM). Second, for authenticated top-k aggregation, we suggest novel schemes using Three Phase Uniform Threshold Algorithm, Merkle Hash Tree, and Condensed-RSA. Third, for detecting malicious nodes, we propose novel algorithms based on Additively Homomorphic Encryption and Multipath Transmission. Our experimental evaluation and security analyses demonstrate that robust mechanisms can be deployed with a minimal amount of computational and communicational expense

Primary extra-cranial meningioma in the right submandibular region of an 18-year-old woman: a case report

<p>Abstract</p> <p>Introduction</p> <p>Extra-cranial meningioma or ectopic meningioma is a rare tumor. This tumor has been reported in various anatomic sites in the head and neck, mediastinum, skin and soft tissues. We report a rare case of ectopic meningioma in the submandibular region detected by using fine-needle aspiration cytology, histopathology and immunohistochemistry. This case represents another unusual site for extra-cranial meningioma, which prompted us to report it.</p> <p>Case presentation</p> <p>An 18-year-old Dravidian woman presented with swelling in the right submandibular region. The computed tomographic scan findings were suggestive of a neoplastic mass lesion in the right submandibular region. Fine-needle aspiration cytology led to the differential diagnosis of a monomorphic adenoma of a salivary gland or an ectopic meningioma. The patient underwent excision of the submandibular gland and tumor. The histological examination and immunohistochemistry studies confirmed that the lesion was an extra-cranial meningioma. At her two-year follow-up examination, there was no recurrence of the tumor.</p> <p>Conclusion</p> <p>Our experience with this case indicates that, although rare, meningioma should be entertained in the differential diagnosis of a mass lesion in the head and neck region.</p

ICAR: endoscopic skull‐base surgery

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Reversed-phase extraction chromatographic separation of zinc(II) with trioctylphosphine oxide

103-106A new method for extraction chromatographic separation of zinc (II) was developed with Trioctylphosphine oxide as the stationary phase and nitric acid as mobile phase on silica gel as stationary support. Zinc was extracted from 2.5 M hydrochloric acid and then stripped with 4 M nitric acid and determined spectrophotometrically at 460 nm by murexide method. Zinc was separated from alkali, alkaline earths, chromium, iron, cobalt, nickel, cadmium, mercury, lead, trivalent rare earths, platinum group metals from binary mixtures by selective extraction of zinc. Zinc is also separated from multicomponent mixtures. The method was extended for the analysis of zinc in alloys and industrial sample

The extraction chromatographic separation of beryllium from aluminium with trioctylphosphine oxide

1243-1246A simple and rapid method for the extraction is described for the separation of beryllium (II) and aluminium (III) from aqueous chloride media with trioctylphosphine oxide (TOPO). A systematic study of the extraction chromatography of chemically similar elements has been carried out separately and it is found that Be (II) and Al (III) get quantitatively extracted at 1.2 M and 0.1M HCI respectively. Based on these results, a sequential method has been developed for the separation of beryllium (II) from aluminium (III). The method is extended for binary and multicomponent separation for beryllium (II) and aluminium (III)

Mercury enrichment in sediments of Amba estuary

89-96 Concentrations of Hg, total organic carbon (TOC), Al, Fe and Mn were determined in sediment of the Amba Estuary between the mouth and the head over a distance of 24 km in December and May during 1997-2002. Temporal and spatial changes in metal concentrations appear to be due to sediment movement associated with tidal movements. The Hg concentration varies in 0.05 -2.66 µg g-1 range and the profiles of its variation indicate Patalganga River that opens in the Amba Estuary is a major source of anthropogenic metal to the estuary. Geoaccumulation index and enrichment factor support Hg contamination of the estuarine sediment to a varying degree. Hg is not significantly correlated with TOC, Al, Fe and Mn in these sediments. </smarttagtype

Liquid-liquid extraction and separation of gallium(III) with Cyanex 921

1114-1116A simple and rapid method for the separation of gallium(III) from aqueous chloride media with tri-n-octylphosphine oxide (Cyanex 921) is described. Gallium(III) has been extracted with Cyanex 921 in toluene in the pH range 4.5-6.0 and stripped back with 2.0 M HNO3. The effects of pH, equilibration period, diluents, diverse ion and stripping agents on the extraction of gallium(III) have been studied. The equilibrium constant and the thermodynamic parameters,ΔH, ΔS and ΔG have been evaluated. The method has been extended for binary and multicomponent separation of gallium(III)

Flushing characteristics and pollution assessment of Purna River Estuary

94-98Tide dominated coastal plain Purna River Estuary was studied to evaluate its flushing characteristics and pollution status. The shallow estuary was generally well-mixed vertically with excellent flushing due to high seawater influx and strong tidal currents. The flushing time of pH and trace metal concentrations in water did not seem to have been grossly affected by the present wastewater inputs. Some influence was however observed on the dissolved oxygen content and BOD specially in the inner estuary

Base-line water quality of the river Narmada (Gujarat)

161-164Suspended solids, pH, chlorides, DO, BOD, PO -P, NO -N and NH -N were estimated at 12 stations along a 70 km stretch from the mouth of the river Narmada during March, May, June and August 1979. Tidal range of over 1 m observed at a point 52 km upstream was due to the piling up of fresh water, and some intrusion of sea water occurred at 44 km upstream in early June when riverine flow had decreased considerably. Significant penetration of saline water was observed only up to 20 km during March. The water column was well mixed vertically with the absence of any significant stratification. High pH of fresh water influenced the pH of the estuarine region which varied considerably over tidal cycles. The estuarine zone was characterized by high, tide dependant, suspended load which decreased appreciably in fresh water region. High overall DO and low BOD indicated the absence of gross organic pollution in the estuarine and riverine zones. NO -N decreased in the downstream direction while PO -P showed an increase; NH -N concentration indicated natural background levels