Applied batch cryptography

The material presented in this thesis may be viewed as comprising two key parts, the first part concerns batch cryptography specifically, whilst the second deals with how this form of cryptography may be applied to security related applications such as electronic cash for improving efficiency of the protocols. The objective of batch cryptography is to devise more efficient primitive cryptographic protocols. In general, these primitives make use of some property such as homomorphism to perform a computationally expensive operation on a collective input set. The idea is to amortise an expensive operation, such as modular exponentiation, over the input. Most of the research work in this field has concentrated on its employment as a batch verifier of digital signatures. It is shown that several new attacks may be launched against these published schemes as some weaknesses are exposed. Another common use of batch cryptography is the simultaneous generation of digital signatures. There is significantly less previous work on this area, and the present schemes have some limited use in practical applications. Several new batch signatures schemes are introduced that improve upon the existing techniques and some practical uses are illustrated. Electronic cash is a technology that demands complex protocols in order to furnish several security properties. These typically include anonymity, traceability of a double spender, and off-line payment features. Presently, the most efficient schemes make use of coin divisibility to withdraw one large financial amount that may be progressively spent with one or more merchants. Several new cash schemes are introduced here that make use of batch cryptography for improving the withdrawal, payment, and deposit of electronic coins. The devised schemes apply both to the batch signature and verification techniques introduced, demonstrating improved performance over the contemporary divisible based structures. The solutions also provide an alternative paradigm for the construction of electronic cash systems. Whilst electronic cash is used as the vehicle for demonstrating the relevance of batch cryptography to security related applications, the applicability of the techniques introduced extends well beyond this.

Compliant cryptologic protocols

Literally, the word compliance suggests conformity in fulfilling official requirements. The thesis presents the results of the analysis and design of a class of protocols called compliant cryptologic protocols (CCP). The thesis presents a notion for compliance in cryptosystems that is conducive as a cryptologic goal. CCP are employed in security systems used by at least two mutually mistrusting sets of entities. The individuals in the sets of entities only trust the design of the security system and any trusted third party the security system may include. Such a security system can be thought of as a broker between the mistrusting sets of entities. In order to provide confidence in operation for the mistrusting sets of entities, CCP must provide compliance verification mechanisms. These mechanisms are employed either by all the entities or a set of authorised entities in the system to verify the compliance of the behaviour of various participating entities with the rules of the system. It is often stated that confidentiality, integrity and authentication are the primary interests of cryptology. It is evident from the literature that authentication mechanisms employ confidentiality and integrity services to achieve their goal. Therefore, the fundamental services that any cryptographic algorithm may provide are confidentiality and integrity only. Since controlling the behaviour of the entities is not a feasible cryptologic goal,the verification of the confidentiality of any data is a futile cryptologic exercise. For example, there exists no cryptologic mechanism that would prevent an entity from willingly or unwillingly exposing its private key corresponding to a certified public key. The confidentiality of the data can only be assumed. Therefore, any verification in cryptologic protocols must take the form of integrity verification mechanisms. Thus, compliance verification must take the form of integrity verification in cryptologic protocols. A definition of compliance that is conducive as a cryptologic goal is presented as a guarantee on the confidentiality and integrity services. The definitions are employed to provide a classification mechanism for various message formats in a cryptologic protocol. The classification assists in the characterisation of protocols, which assists in providing a focus for the goals of the research. The resulting concrete goal of the research is the study of those protocols that employ message formats to provide restricted confidentiality and universal integrity services to selected data. The thesis proposes an informal technique to understand, analyse and synthesise the integrity goals of a protocol system. The thesis contains a study of key recovery,electronic cash, peer-review, electronic auction, and electronic voting protocols. All these protocols contain message format that provide restricted confidentiality and universal integrity services to selected data. The study of key recovery systems aims to achieve robust key recovery relying only on the certification procedure and without the need for tamper-resistant system modules. The result of this study is a new technique for the design of key recovery systems called hybrid key escrow. The thesis identifies a class of compliant cryptologic protocols called secure selection protocols (SSP). The uniqueness of this class of protocols is the similarity in the goals of the member protocols, namely peer-review, electronic auction and electronic voting. The problem statement describing the goals of these protocols contain a tuple,(I, D), where I usually refers to an identity of a participant and D usually refers to the data selected by the participant. SSP are interested in providing confidentiality service to the tuple for hiding the relationship between I and D, and integrity service to the tuple after its formation to prevent the modification of the tuple. The thesis provides a schema to solve the instances of SSP by employing the electronic cash technology. The thesis makes a distinction between electronic cash technology and electronic payment technology. It will treat electronic cash technology to be a certification mechanism that allows the participants to obtain a certificate on their public key, without revealing the certificate or the public key to the certifier. The thesis abstracts the certificate and the public key as the data structure called anonymous token. It proposes design schemes for the peer-review, e-auction and e-voting protocols by employing the schema with the anonymous token abstraction. The thesis concludes by providing a variety of problem statements for future research that would further enrich the literature.

基于可信计算平台的电子现金技术

基于可信计算平台提出了一种新的离线电子现金方案,该方案将电子现金、用户身份、平台身份三者有机绑定在一起,利用可信计算平台的认证技术和存储保护功能,极大地增强了电子现金的安全性,同时还具有支付起源非否认、电子现金有限流通期限等特点.该方案对于电子现金的备份,电子现金的盗用和丢失,都提供了良好的保护,并对所提出的电子现金协议进行了详细的安全性分析.

From Cash to Electronic Payments: Microeconomic, Macroeconomic, and Policy Aspects of Retail Payment Systems

This dissertation explores three aspects of the economics and policy issues surrounding retail payments (low-value frequent payments): the microeconomic aspect, by measuring costs associated with retail payment instruments; the macroeconomic aspect, by quantifying the impact of the use of electronic rather than paper-based payment instruments on consumption and GDP; and the policy aspect, by identifying barriers that keep countries stuck with outdated payment systems, and recommending policy interventions to move forward with payments modernization. Payment system modernization has become a prominent part of the financial sector reform agenda in many advanced and developing countries. Greater use of electronic payments rather than cash and other paper-based instruments would have important economic and social benefits, including lower costs and thereby increased economic efficiency and higher incomes, while broadening access to the financial system, notably for people with moderate and low incomes. The dissertation starts with a general introduction on retail payments. Chapter 1 develops a theoretical model for measuring payments costs, and applies the model to Guyana—an emerging market in the midst of the transition from paper to electronic payments. Using primary survey data from Guyanese consumers, the results of the analysis indicate that annual costs related to the use of cash by consumers reach 2.5 percent of the country’s GDP. Switching to electronic payment instruments would provide savings amounting to 1 percent of GDP per year. Chapter 2 broadens the analysis to calculate the macroeconomic impacts of a move to electronic payments. Using a unique panel dataset of 76 countries across the 17-year span from 1998 to 2014 and a pooled OLS country fixed effects model, Chapter 2 finds that on average, use of debit and credit cards contribute USD 16.2 billion to annual global consumption, and USD 160 billion to overall annual global GDP. Chapter 3 provides an in-depth assessment of the Albanian payment cards and remittances market and recommends a set of incentives and regulations (both carrots and sticks) that would allow the country to modernize its payment system. Finally, the conclusion summarizes the lessons of the dissertation’s research and brings forward issues to be explored by future research in the retail payments area.

Farm Programmes of Electronic Media: A Comparative Study of Audience Perception in Kerala

Farm communication and extension programs are vital part of the farm development attempts. Electronic media plays a major role in farm extension activities. Kerala, the consumer state, which was a complete agricultural state in pre-independence period, is the sprouting land of agricultural extension and publication activities in print media. Later AIR (All India Radio) farm programs and farm broadcasting of Doordarshan enriched the role of electronic media in farm extension activities. The media saturated southern state of India received this new electronic media farm communication revolution whole heartedly. However, after 1990, Kerala witnessed a flood of private T V channels and currently there are 24 channels in this regional language, named Malayalam. All major news and entertainment channels are broadcasting farm programs. Farm programs of AIR and Doordarshan, broadcasted in Malayalam language, have been well accepted to the farmers‘ in Kerala. However, post-independence period, witnessed the formation of Kerala state in Indian Union and the first ballot-elected communist Government started its administration. After the land reform bills, the state witnessed a gradual decrease in agricultural production. Even if it is not reflected much in the attitude and practices of farm community and farm broadcast of traditional electronic broadcasting, a change is observable after the post-liberalization era of India. Private Television channels, which were focused on entertainment value of programs, started broadcasting farm programs and the parameters of program production went through certain changes. In this situation, there is ample relevance for a study about the farm programs of electronic media in terms of a comparative study of audience perception. The study is limited in the state of Kerala as it is the most media saturated state in India. The study analyzes the rate, nature and scope of adoption of farming methods transmitted through electronic media (T.V. and Radio) in Malayalam language.All kinds of Farm programs including comprehensive program serials, success stories, seasonal cropping methods, experts opinion, been analyzed on the basis of the following objectives.  To find whether propagating new farm methods through farm programs in electronic media or the availability of adequate infrastructure and economic factors make a farmer to adopt a new farming method.  To find which electronic media has more influence on farmers to adopt agricultural programs.  To find which form of electronic media gets better feedback from farmers  To find out whether the programs of T.V. or Radio is more acceptable to farmers than the print media.  To find whether farmers gets the message through their preferred medium for the message. The researcher recorded opinions from a panel of agricultural officers, farm Information officers, agro extension researchers and experts. According to their opinions and guidelines, a pilot study is designed and conducted in Kanjikuzhy Panchayath, in Alappuzha district, Kerala. The Panchayath is selected by considering its ideal nature of being the sample for a social Science research. Besides, the nature of farming in the Panchayath, which devoid of the cultivation of cash crops also supported its sample value. As per the observations from the pilot study, researcher confirmed the Triangulation method as the methodology of research. The questionnaire survey, being the primary part contained 42 Questions with 6 independent and 32 dependent variables. The survey is conducted among 400 respondents in Idukki, Alappuzha and Pathanamthitta districts considering geographical differences and distribution of different types of crops. The response from a total of 360 respondents, 120 from each district, finally selected for tabulation and data analysis.The data analysis, based on percentage analysis, along with the results from focus group discussion among a selected group of 20 farmers, together produced the results as follows. Farmers, who are the audience of farm programs, have a very serious approach towards the medium. They are maintaining a critical point of view towards the content of the programs. Farmers are reasonably aware about the financial side of the programs and the monitory aspirations of both private and Government owned Television channels. Even though, the farmers are not aware on the technical terminology and jargons, they have ideas about success stories, program serials and they are even informed about channels are not maintaining an audience research section like AIR. Though the farmers accept Doordarshan as the credential source of farm information and methods, they are inclined to the entertainment value of programs too. They prefer to have more entertainment value for the programs of Doordarshan. Surprisingly, they have very solid suggestions on even about the shots which add entertainment value to the farm broadcasting methods of Doordarshan. Farmers are very much aware about the fact that media is just an instrument for inspiration and persuasion. They strongly believe that the source of information and new methods is agricultural research and an effective change happens only when there are adequate infrastructure and marketing facilities, along with the proper support from Government agricultural guideline and support systems like Krishi Bhavans. They strongly believe that media alone cannot create any magic in increasing agricultural production. Farmers are pointing out the lack of response to the feedback and queries of farmers on farming methods, as an evidence for the difference in levels of commitment of Government and private owned Television channels.Farmers are still perceiving AIR farm programs are far more committed to farmers and farming than any other electronic medium. However, they are seriously lacking Radio receivers with medium wave reception facility. Farmers perceive that the farming methods on new crops are more adoptable than the farming methods of traditional crops in both private and Government owned Television channels. There are multiple factors behind this observation from farmers. Farmers changed in terms of viewing habits and they prefer success stories, which are totally irrelevant and they even think that such stories encourage people to go for farming and they opined that such stories are good sources of inspiration. However, they are all very much sure about the importance and particular about the presence of entertainment factor even in farm programs. Farmers expect direct interaction of any expert of the new farming method to implement the method in their agriculture practices. Though introduction of a new idea in the T.V. is acceptable, farmers need the direct instruction of expert on field to start implementing the new farming practices Farmers still have an affinity towards print media reports and agricultural pages and they have complaints to print media on the removal of agricultural information pages from news papers. They prefer the reports in print media as it facilitates them to collect and refer articles when they need it. Farmers are having an eye of doubt about the credibility of farm programs by private T.V. channels. Even if they prefer private Television channels for listening and adopting new farming methods and other farm information, they scrutinize programs to know whether they are sponsored programs by agrochemical or agro-fertilizer manufacturer.

WREN: electronic management system for facilities management

This paper describes a case study of an electronic data management system developed in-house by the Facilities Management Directorate (FMD) of an educational institution in the UK. The FMD Maintenance and Business Services department is responsible for the maintenance of the built-estate owned by the university. The department needs to have a clear definition of the type of work undertaken and the administration that enables any maintenance work to be carried out. These include the management of resources, budget, cash flow and workflow of reactive, preventative and planned maintenance of the campus. In order to be more efficient in supporting the business process, the FMD had decided to move from a paper-based information system to an electronic system, WREN, to support the business process of the FMD. Some of the main advantages of WREN are that it is tailor-made to fit the purpose of the users; it is cost effective when it comes to modifications on the system; and the database can also be used as a knowledge management tool. There is a trade-off; as WREN is tailored to the specific requirements of the FMD, it may not be easy to implement within a different institution without extensive modifications. However, WREN is successful in not only allowing the FMD to carry out the tasks of maintaining and looking after the built-estate of the university, but also has achieved its aim to minimise costs and maximise efficiency.

Cash or non-cash: that is the question - the story of e-payment for social welfare in Ireland part 2

E-Government in its various forms and extensions, notably T-Government, is often presented as the panacea for resolving such complex social problems as social exclusion, lack of governance transparency, poor value for money and other ailments of modern societies. Yet, E-Government has not been adopted up to predicted levels. Many case studies investigating success factors, maturity models, and the application of acceptance models have been presented over the last 15 years, but a deep understanding of the potential impact and consequences of E-Government is still lacking. This is especially true for those initiatives that involve socio-economic and cultural contexts, which makes their evaluation and the prediction of their impact difficult. This paper reports on an on-going E-Government initiative in Ireland aimed at implementing E-payments for G2C, notably in the social welfare area. Three sets of personal surveys have been carried out to understand the perceived impact of governmental plans of moving from an almost fully cash-based payment system to a fully electronic based solution. Early results indicate that perceived pre-requisites for the planned change may be misleading. The impact on recipients’ lives cannot solely be measured in terms of economic gains: the consequences of such implementation may well reach further than expected.

Electronic and vibrational spectra of gaspeite

Visible, near-infrared, IR and Raman spectra of magnesian gaspeite are presented. Nickel ion is the main source of the electronic bands as it is the principal component in the mineral where as the bands in IR and Raman spectra are due to the vibrational processes in the carbonate ion as an entity. The combination of electronic absorption and vibrational spectra (including near-infrared, FTIR and Raman) of magnesian gaspeite are explained in terms of the cation co-ordination and the behaviour of CO32– anion in the Ni–Mg carbonate. The electronic absorption spectrum consists of three broad and intense bands at 8130, 13160 and 22730 cm–1 due to spin-allowed transitions and two weak bands at 20410 and 30300 cm–1 are assigned to spin-forbidden transitions of Ni2+ in an octahedral symmetry. The crystal field parameters evaluated from the observed bands are Dq = 810; B = 800 and C = 3200 cm–1. The two bands in the near-infrared spectrum at 4330 and 5130 cm–1 are overtone and combination of CO32– vibrational modes. For the carbonate group, infrared bands are observed at 1020 cm–1(1 ), 870 cm–1 (2), 1418 cm–1 (3) and 750 cm–1 (4), of which3, the asymmetric stretching mode is most intense. Three well resolved Raman bands at 1571, 1088 and 331 cm–1 are assigned to 3, 1 and MO stretching vibrations.