In cryptography, the notion of zero-knowledge is important. It is also related to complexity theory. In this paper we briefly survey the zero-knowledge proofs in the literature. 1987 Maathematics Subject Classification: 69D56, 69E30, 69F21, Keywords and phrases: interactive proofs, zero-kniwledge, cryptography, complexity theiry.
The Chilean vocational training system is essentially different from the typical Latin American model where services are provided by an official, largely monopolistic, Vocational Training Institution (VTI), financed mainly by a payroll levy on firms. Instead, Chile has a legally established, market oriented system in which many private training agencies compete to sell their services to private firms and government-sponsored public training programmes.
We show how to construct a "zero-knowledge proof" that a circuit of size m is satisfiable. The proof is a string of length O(m lg m) which is constructed (and can be verified) using a trusted random string of length O(m lg m). The probability of failure or of cheating is exponentially small in a security parameter which is defined independently Supported in part by NSF Grant CCR-9207204. of the circuit size. Our methods assume that a Quadratic Residuosity Bit Commitment Scheme is available as a primitive and does not consider the cost of establishing this scheme, only the cost of using it. Thus, these "proofs" are essentially non-interactive zero-knowledge proofs, with a couple of changes to the standard definition, though they can easily be modified to fit the standard definition. The techniques used yield more efficient "proofs" than those previously known. 1 Introduction A non-interactive zero-knowledge proof system is a protocol that allows a prover to convince a verifier tha...
Physical Unclonable Functions (PUFs) and Hardware Security
Decentralization has been a popular theme in development thinking and practice due to the impact of decentralisation of government expenditures and revenues upon human development. This survey explores the extensive literature on decentralisation, revealing the lack of quantitative and rigorous studies. A detailed analysis of the various dimensions of decentralisation - participation, financing and comparative priorities - and of the relevant effects upon efficiency, resource availability and equity, enable the author to draw some interesting lessons from its theory and practice.
headlines of newspapers nationwide are ablaze with stories about wage freezes, mergers, plant closings and scandal in Corporate America. It's no wonder employees of these companies harbor anxieties about their job security and the future of their workplaces. Even when dispensing unfavorable news, forthright and timely internal communications play a major part in quelling the fears and doubts of employees. Employees seek honest answers directly from management, not speculative stories in the morning newspaper. This article shows how six companies have used employee communications to convey bad news. each case, the company has faced negative public opinion, uncomplimentary news coverage, internal shake-ups, or simply slumping profits, either recently or in the past few years. Boeing has had to handle massive layoffs. Northwest Airlines also faced cost and wage cuts, along with a public court battle over fares with a major competitor and an unfriendly media environment. Empire Blue Cross Blue Shield recently faced a scandal over its financial management and personnel changes at the top, along with 25% to 30% annual health insurance premium cost increases that had consumers and some of the press screaming. Time Warner Inc. struggled through four years of cultural upheaval caused by an expensive merger involving a hostile takeover, compounded by its production of controversial products and management maneuvering at the top of the company. And, two years ago, Citibank, Inc. embarked on a worldwide campaign to shore up its profitability. Regardless of the messages involved, all of these organizations have gone to great lengths in efforts to share up-to-the-minute controversial news with employees. They used various communications tactics and mediums, including: * Special editions of company-produced newspapers offering lengthy explanations of all pertinent events as well as progress reports in letter format from the president/CEO. * Videotaped or in-person appearances by the company's chairman of the board/CEO addressing employee concerns such as the company's financial stability, job security, opportunities for career advancement and market share erosion. * Monthly staff meetings for officers and directors during the crisis period to keep everyone abreast of the latest news. Mid-level managers are also encouraged to be there for employees they supervise to foster a we're all in this together attitude. * Town meetings, allowing open forums between the president/CEO or managers, and randomly selected employees. * A series of mental and physical health workshops aimed at helping employees deal with job-related stress on their lives. * Programs to encourage employees to stay charged and professional. Established communications systems allow for a quick turnaround of information in a highly volatile or crisis situation. But lessons in crisis communications are sometimes learned along the way. After its merger, Time Warner Inc. had to overcome the internal communications barriers between six decentralized, autonomous business divisions. It has taken but the company now has a smooth, workable total system. Two merged Kansas-based power companies learned a similar lesson when they tried to build a new, integrated culture. Northwest's spiral of turmoil Northwest Airlines had a convergence of several negative events all at once, starting in the summer of 1992, said Jeff Smith, director internal communications for the St. Paul, MN-based company. A federal court battle developed between Northwest and American Airlines after the latter made deep fare cuts. That started a spiral of bad (revenue) months for us, he said. In spring '92, we had no other alternative but to ask our labor groups to begin negotiating more than $900 million in reduced costs over three years, Smith continued. The lengthy process of those intense negotiations and all of the information and misinformation about the company caused a great deal of anxiety internally. âŠ
Private sector involvement and user participation in water resource management are not new, say the authors. They give examples that demonstrate how willing users and the private sector are able to improve water use and play a larger role in water resources management. User participation and private sector involvement, if properly structured, can provide the incentives needed to stabilize and improve the efficiency of irrigation and water supply systems. They can add flexibility, transparency, and accountability and can reduce the state's administrative and financial burden. A 1989 World Bank review of 21 impact evaluations of irrigation projects, for example, found cost recovery to be excellent in those projects in which water management and operations and maintenance had been entrusted to water users. Greater private sector and user participation can effectively increase user responsibility for managing and financing water projects while freeing governments to focus on broader water resource management concerns. The authors provide examples of decentralized water management in developing country water supply and irrigation systems. Governments should: more actively regulate private sector exploitation of groundwater, especially for irrigation; take measures to encourage price competition among private suppliers of water for both domestic and agricultural uses; and play an active role in organizing water user associations, especially for irrigation and rural water supply systems, and in giving them technical assistance. As numerous examples highlight, such activities should be designed to reduce the transaction costs of organizing and to establish a sense of assurance and accountability within the water user community. Once this is done, the community can deal with problems associated with excludability and unwillingness to pay.
The studies and cases reviewed by the authors suggest that settlement programs are too often designed on the assumption that all settlers will or can succeed. This had led to too much centralized administration and rigid designs, rather than reliance on decentralized approaches, flexibility in implementation, support for spontaneous settlement, and reliance on the settler's own investment capacity. Collective forms of crop production have not worked. Cropland is best allocated to individual families whose land rights must be clearly defined as ownership or long-term leases. Farm sizes must be flexibly adjusted to skills, the availability of family labor, and the families'capital ownership. Settlers should therefore be allowed to sell or rent the land to other beneficiaries. If poor settlers are to benefit or succeed, settlement cannot be based on credit finance but must include grants. Paternalistic constraints on the choice of crops or technologies, marketing, or participation in the labor force have usually not been enforceable or have had negative effects.
Abstract Mongolia is the second oldest communist regime after Russia, and its reforms have been under way since 1986. It is a landâlocked state and is characterized by its large physical size relative to a small population, an almost total historical dependence on the formerâUSSR and a limited range of agricultural and mineral resources. Despite the profound effects that the collapse of the USSR and Comecon have caused, Mongolia has adopted a âshock therapyâ approach to reform, embarking simultaneously on a bold programme of both political and economic change. This article traces the genesis of the reform strategy, highlighting the interplay between external events and internal debate and sometimes outlining the major areas of the reform programme: the introduction of macroeconomic management to replace central planning, the improvement of incentives and an ambitious programme of privatization. The undertaking of such a programme in the Mongolia points to the importance of a social safety net and popular support for the reforms. The article then describes the complementary reforms of public administration that have been more recently introduced in the wake of a new constitution, with their emphasis on professionalization of government administration, transfer of responsibilities to provincial and local government and improved policies and institutions for national training. International technical assistance has and continues to play a significant role in supporting the above. A number of lessons are drawn with regard to strategy, particularly the need at programme level for an integrated or systems approach that can ensure linkages between different elements and at the level of training the need for imaginative approaches to design and delivery. The article draws conclusions on the prospects for success in each area of the reform programme. Critical for public administration restructuring and professionalization is the issue of institutional capacity for implementation. While the legal framework has now been laid down for decentralized government, for example, there is little prior experience in local government of many areas of functional management, finance and budgeting, investment planning and social services administration. On the economic front, the shock therapy stragegy has been adopted despite some earlier advice on the preconditions for successful privatizationâwith regard for example to market structure, the development of the financial sector and most crucially the continued role of the state in fostering entrepreâneurship in a society devoid of any recent history of such.
Advanced industrial countries around the world are making or contemplating major reforms of their systems for financing and organizing long-term care for the elderly. The paper describes major reform efforts including: the pursuit of cost efficiencies from further differentiation of the acute and long-term care delivery systems, promotion of home and community-based care alternatives to traditional institutions, and âsystems integrationâ involving consolidation of responsibility for long-term care at one level of government. The paper concludes by discussing the special relevance to the long-term care reform debate in the U.S. of recent British and German decisions to, respectively, decentralize versus centralize responsibility for long-term care.
THE RHETORICAL STRUCTURE The introductory comments made about rhetoric in our discussion of 1 Thessalonians are relevant to 2 Thessalonians and we urge the reader to review that material at this time. There is wide consensus that 2 Thessalonians belongs to the deliberative genre of rhetoric. This genre includes honour and advantage as the standard topics. These topics are used in 2 Thessalonians to advise the audience concerning their present actions and the result of those actions in the future. Frank Witt Hughes provides the following analysis of the rhetorical structure of 2 Thessalonians. It is one that we accept. I Exordium (introduction) (1:1â12) A epistolary prescript (1:1â2) B thanksgiving prayer (1:3â10) C intercessory prayer (1:11â12) II Partitio (statement of the proposition) (2:1â2) A subjects to be dealt with in the probatio (2:1â2) B point of disagreement (heresy to be refuted) (2:2) III Probatio (proof) (2:3â15) A a first proof (refutatio) (2:3â12) B second proof (2:13â15) IV Peroratio (epilogue) (stated as an intercessory prayer; 2:16â18) V Exhortation (3:1â15) A command (or request) to pray for Paul (3:1â4) B intercessory prayer (3:5) C command to work (3:6â15) VI Epistolary postscript (3:16â17) A intercessory prayer (3:16) B authentication (3:17) C final blessing (3:18) Knowing that 2 Thessalonians is an example of deliberate rhetoric permits the interpreter to be sensitive to the argumentation of the letter in general, and by examining the various components of this rhetorical structure one can be made sensitive to the central issues at stake in the dialogue between this author and his audience.
The financing of a Stateâs sub-national levels of government, in federal and other systems alike, is an instrument of decentralization; first, each State has to decide what area of responsibility to assign to each governmental level and then it must design a suitable financing mechanism. If these sub-national governmentsâ degrees of fiscal and administrative autonomy are not kept in alignment, then eventually the initiative may fait as the bodies at these levels gradually lose decision-making power within their sphere of responsibility.
China's thirteen years of economic reforms (1979-1991) have achieved an average GNP annual growth rate of 8.6%.What makes China's reforms differ from those of Eastern Europe and the Soviet Union is the sustained entry and expansion of the non-state sector.We argue that the organization structure of the economy matters.Unlike their unitary hierarchical structure based on functional or specialization principles (the Uform), China's hierarchical economy has been the multi-layer-multi-regional one mainly based on territorial principle (the deep M-form, or briefly, the M-form).Reforms have further decentralized the M-form economy along regional lines, which provided flexibility and opportunities for carrying out regional experiments, for the rise of nonstate enterprises, and for the emergence of markets.This is why China's non-state sector share of industrial output increased from 22% in 1978 to 47% in 1991 and its private sector's share from zero to about 10%, both being achieved without mass privatization and changes in the political system.2 Data sources in this paper are from Statistical Yearbook of China (various issues from 1985 to 1992), otherwise noted.3 Statistical Communique of the State Statistical Bureau on the 1992 National Economic and Social Development, February 18, 1992. 4 The export-GNP ratios are calculated based on the official exchange rate and are upward biased.But the dramatic increase of export share in GNP during the reform is unmistaken. 2 both before and after their radical transformations in 1989.It appears that China had no coherent reform programs, no commitment to private ownership, and no changes in the political system, and China's economy was still not fully liberalized.From both the theoretical and policy perspectives, China's different reform strategies and outstanding reform performances are particularly interesting and puzzling.The economic reforms in China formally started in 1979 following the Third Plenum of the Eleventh Congress of the Chinese Communist Party in December 1978.The starting time was later than that of Yugoslavia (1950) and Hungary ( 1968) and was about the same as for Poland (1980), and earlier than the Soviet Union (1986).Between 1979 and 1991, China's GNP grew at an average annual rate of 8.6%, or at 7.2% on the per capita basis. 2 In 1992, the growth of GNP reached 12.8%. 3Exports grew at a faster pace, so that China's export-GNP ratio increased from below 5% in 1978 to nearly 20% in 1991. 4 Also in this period, inflation was kept within a single-digit range except for three years (11.9% in 1985, 20.7% in 1988 and 16.3% in 1989); the household bank deposits to GNP ratio increased from 6% in 1978 to 46% in 1991; and the government budget deficit accounted for about 2-3% of GNP, about half of which was financed from bond issues (Table 1.1).Even more convincing evidence of the success of the reform is the increase in consumption and consumer durable goods by an average Chinese consumer in physical terms.For example, between 1978 and 1991, an average Chinese consumer increased his/her consumption about three times for edible vegetable oil, pork, and eggs (Table 1.2).In the rural areas, which account for about 75% of total population, the living space per person increased about 130% between 1978 and 1991 (Table 1.3).The 5 Data source for Hungary and Poland is from Table 9.1 of Kornai (1992).6 For example, Summers (1992) expressed this view when he highly praised China's reform performance.Sachs (1992) also expressed similar ideas during his interview with the Chinese Journal of Comparative Economic and Social Systems.