There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

The objective of this paper is to give a comprehensive introduction to applied cryptography with an engineer or computer scientist in mind. The emphasis is on the knowledge needed to create practical systems which supports integrity, confidentiality, or authenticity. Topics covered includes an introduction to the concepts in cryptography, attacks against cryptographic systems, key use and handling, random bit generation, encryption modes, and message authentication codes. Recommendations on algorithms and further reading is given in the end of the paper. This paper should make the reader able to build, understand and evaluate system descriptions and designs based on the cryptographic components described in the paper.

[서평]「Applied Cryptography」

Object-oriented analysis

The Convolution Transform. By Hirschmann & Widder . Pp. x + 268. 45s. 1955. (Princeton University Press. London : Cumberlege)

There is no escaping fact that a huge amount of unexploited resources lies underwater which covers almost 70% of the Earth. Yet, the aquatic world has mainly been unaffected by the recent advances in the area of wireless sensor networks (WSNs) and their pervasive penetration in modern day research and industrial development. The current pace of research in the area of underwater sensor networks (UWSNs) is slow due to the difficulties arising in transferring the state-of-the-art WSNs to their underwater equivalent. Maximum underwater deployments rely on acoustics for enabling communication combined with special sensors having the capacity to take on harsh environment of the oceans. However, sensing and subsequent transmission tend to vary as per different subsea environments; for example, deep sea exploration requires altogether a different approach for communication as compared to shallow water communication. This paper particularly focuses on comprehensively gathering most recent developments in UWSN applications and their deployments. We have classified the underwater applications into five main classes, namely, monitoring, disaster, military, navigation, and sports, to cover the large spectrum of UWSN. The applications are further divided into relevant subclasses. We have also shown the challenges and opportunities faced by recent deployments of UWSN.

https://journals.sagepub.com/doi/pdf/10.1155/2015/896832

Underwater sensor network applications: a comprehensive survey

Shill bidding is a fraudulent act whereby a seller places bids on his/her own auction to drive up the final price for the winning bidder. eBay currently masks bidder usernames in auctions and has adopted a 30-Day Bid Summary that restricts the availability of data on the previous auctions a bidder has participated in. This has made shill bidding detection more difficult, as tracking users across multiple auctions is essential in identifying shills. This paper presents two pieces of software to aid in the detection of shill bidding in light of masked bidder usernames and limited bid history data. First, we propose the Auction Data Collector to automatically acquire vital eBay auction data required for shill bidding detection. Second, we propose the BidderLinker Algorithm, which links bidders across multiple auctions they have bid on with the same seller by utilising the 30-Day Bid Summary. The 30-Day Bid Summary provides information about bidders that can be used to uniquely identify them, even if their usernames are masked. This allows for shill detection algorithms to be applied to the data gathered from multiple auctions with the same seller, where previously this was not possible.

Detecting Shill Bidding Using eBay’s 30-Day Bid Summary

Wireless sensor networks (WSNs) employ middleware solutions to coordinate their sensors and provide web services for managing data. Adding/configuring a new or existing sensor requires modification to the middleware and web service. To integrate hundreds of sensors with different capabilities, a system needs to support all the encodings, models and services for registering, tasking and querying sensors. We present an intelligent agent, which provides automatic semantic-based registration/configuration in a large-scale sensor observation system. The agent can react to any changes internally/externally made (i.e., adding a new sensor or sending a task request to sensors/support systems). The agent makes a 'smart' decision on which system function to use by integrating a semantic representation of sensor network data including middleware and web service specifications and applying logical rules to the knowledge-base. The agent's operation is demonstrated using two real-world systems represented in RDF using a domain ontology that extends the W3C SSN-XG ontology.

An intelligent agent system for managing heterogeneous sensors in dispersed and disparate wireless sensor network

Online auctions are inherently insecure and there exist many opportunities for participants to cheat. Cryptographic protocols can be applied to help alleviate some of these problems. However, different auction types have differing security requirements. This makes it difficult to construct schemes to prevent all possible forms of dubious behaviour. This paper presents a survey of cryptographic schemes that have been proposed for conducting private and secure auctions. The major auction types are investigated and their privacy and security requirements contrasted. We provide a uniform analysis of each auction scheme's functional components and analyse the efficiency of the security mechanisms. The paper's motivation is to give an all-encompassing overview of auction privacy and security, which has not been documented elsewhere. This paper supports supplementary research by the author into online auction fraud and security issues. We show that most schemes are currently not practical and there are conflicting perspectives regarding security requirements. Avenues for future research are proposed with regard to the present lacking state of commercial online auction security.

Cryptographic online auction schemes

Aquatic environmental sensors are expensive which limits the ability to undertake widescale remote monitoring. In most instances, too much logic and functionality are contained within the sensor device itself. This approach is expensive and computationally restrictive. This paper presents a new architectural paradigm for remotely deployed sensors whereby the calibration logic (and other functionality) is separated from the physical sensor hardware. A sensor device is only responsible for taking raw unprocessed sensor readings, which are transmitted back to a central server. All processing occurs on the server where computational capability and sophistication are unbounded. This approach allows for significant flexibility in terms of dynamic calibration adjustments to be applied to sensor data (e.g., in the case of sensor fouling or device decay) and for statistical quality assurance/data production algorithms to be applied. We present an example of how this paradigm can be adopted in this context to a turbidity sensor.

/pdf/the-virtual-sensor-concept-separating-sensor-software-from-1xttpbvyq2.pdf

The Virtual Sensor Concept : Separating Sensor Software from the Hardware

Online share trading has made investing in share markets more accessible to novice traders. Investors can
trade from the comfort and privacy of their own homes. However, there are many inherent risks in online share trading. Share markets are becoming the target of new elaborate scams, terrorist attacks and corporate crimes. This paper provides an overview of privacy and security for online share trading in the context of auctions. We discuss the additional parties involved, and how their individual requirements affect auction security and privacy. We give a description of share market related crimes and their implications for online trading. We investigate existing security mechanisms and cryptographic solutions to these problems. This paper presents an auction scheme for anonymous and secure share transactions.

Jarrod Trevathan

Papers

Detecting Shill Bidding Using eBay’s 30-Day Bid Summary

An intelligent agent system for managing heterogeneous sensors in dispersed and disparate wireless sensor network

Cryptographic online auction schemes

The Virtual Sensor Concept : Separating Sensor Software from the Hardware

Privacy and security concerns for online share trading