Efficient modular arithmetic units for low power cryptographic applications

The demand for high security in energy constrained devices such as mobiles and PDAs is growing rapidly. This leads to the need for efficient design of cryptographic algorithms which offer data integrity, authentication, non-repudiation and confidentiality of the encrypted data and communication channels. The public key cryptography is an ideal choice for data integrity, authentication and non-repudiation whereas the private key cryptography ensures the confidentiality of the data transmitted. The latter has an extremely high encryption speed but it has certain limitations which make it unsuitable for use in certain applications. Numerous public key cryptographic algorithms are available in the literature which comprise modular arithmetic modules such as modular addition, multiplication, inversion and exponentiation. Recently, numerous cryptographic algorithms have been proposed based on modular arithmetic which are scalable, do word based operations and efficient in various aspects. The modular arithmetic modules play a crucial role in the overall performance of the cryptographic processor. Hence, better results can be obtained by designing efficient arithmetic modules such as modular addition, multiplication, exponentiation and squaring. This thesis is organized into three papers, describes the efficient implementation of modular arithmetic units, application of these modules in International Data Encryption Algorithm (IDEA). Second paper describes the IDEA algorithm implementation using the existing techniques and using the proposed efficient modular units. The third paper describes the fault tolerant design of a modular unit which has online self-checking capability --Abstract, page iv

Challenges of Auditors and Audit Reporting in a Corrupt Environment

The rising spate of corruption in both private and public establishments has assumed an enormous dimension. This development has eroded public trust in financial statements. Auditors in their duty to expressing professional opinion on the truth and fairness of financials are ostensibly bedeviled with quantum of challenges which could result in the issuance of a clean bill of health to corruption-riddled establishments. It is against this background that this paper critically examines the challenges corruption poses to auditors and audit reporting, and proffers formidable cures to ameliorate the achilles heels and to redeem the auditing profession from impeding collapse. Keywords: auditors, corruption, audit reportin

Government Accountability and Voluntary Tax Compliance in Nigeria

This study examines the nexus between government accountability and voluntary tax compliance based on the theoretical framework that there exist a relational fiscal/social contract between the state and the citizens. Specifically, the hypothesis that voluntary tax compliance is influenced by the individuals’ perception of government accountability was specified and tested. Primary data elicited using structured likert scale questionnaire was used for the study while the Z- scores were computed and used to test the hypothesis. The Findings were in the affirmative indicating that the citizens’ perception of government accountability is an instrumental factor that shapes the emergence and maintenance of tax morale resulting in voluntary tax compliance. The study recommends is that to reduce tax gap, voluntary compliance should be motivated by improving the quality of public governance. Keywords: voluntary tax compliance, tax morale, government accountability

Determinants of Audit Delay in Nigerian Companies: Empirical Evidence

This paper examines relationship between audit delay and several company characteristics in Nigeria. The objective of this study is to measure the extent of audit lag in Nigeria and to establish the impact of selected corporate attributes on audit delay in Nigeria. A sample of 20 quoted companies was selected for a period of 2009 to 2011. The audit delay for each of the companies revealed that it takes a minimum of 30 days and a maximum of 276 days for Nigerian companies to publish their annual reports. Nigeria listed companies take approximately two months on the average beyond their balance sheet date before they are finally ready for the presentation of the audited accounts to the shareholders at the annual general meetings. The results from the panel data which was estimated using Ordinary Least Square regression showed that the major determinants of audit delay in Nigeria include multinationality connections of companies, company size and audit fees paid to auditors. We therefore recommend that regulatory agencies in Nigeria should probe audit delay and formulate policies to enforce compliance with timely release of annual reports. Keywords: audit delay, audit lag, annual reports, company characteristic

Price Level Changes and Financial Accounting Measurement:Empirical Evidences from Nigeria

This study discusses the impact of price level changes on financial accounting numbers. Previous studies on the subject have merely reproduced historical financial statements alongside ‘inflation-adjusted’ financial statements without any scientific methodology and empirical analyses to allow for reliable conclusions. It is this major gap that this study seeks to fill. A sample of ten firms was drawn for period between2001-2010. The OLS regression estimated at nominal and adjusted levels in two separate models showed that both models have a high goodness of fit (R2 ). However, the adjusted estimate exhibited a higher explanatory power and thus shows a better fit. This suggested that adjusted accounting estimates may after all be able to provide better and more realistic insight into a firm’s state of affairs. The study recommends that historical financial accounting information should be presented side-by-side with their corresponding adjusted financial statement to disclose the effect of price level changes. Additionally, the Financial Reporting Council of Nigeria and other regulatory agencies should as a matter of necessity set up a system of accounting for price level changes to enhance the value relevance of accounting informatio

Deterrent Tax Measures and Tax Compliance in Nigeria

Over the years, many developed economies have made considerable investment in legislative tax reforms, taxpayer education programs, tax enforcement strategies, and increasingly sophisticated systems of tax administration using new technologies. Undoubtedly, there are lessons to be learnt from studying best practices in developed economies. However, compared to their counterparts in developed economies, policy makers and revenue authorities in developing economies face quite different challenges and constraints that require careful consideration in designing appropriate and effective tax systems. This paper examines the effects of deterrent tax measures on tax compliance in Nigeria. Following the introduction, we reviewed the existing tax policies and reforms in Nigeria. This is followed by a discussion of the various compliance strategies prescribed in the literature from where we developed our hypotheses. The method of data analysis used in the study is the ordinary least square (OLS) regression technique. This method was adopted because of its properties of consistency, unbiasedness and efficiency. The OLS regression technique was estimated using computer software (Microfit 4.1).  It was observed that the existing deterrent tax measures in Nigeria are inadequate and have not helped to promote tax compliance in the country. It was also discovered that fostering voluntary compliance and enhancing taxpayer’s morale will enhance tax compliance. We recommend that the Nigerian revenue authorities should strive to adopt the approach that will encourage voluntary compliance and prescribe appropriate sanctions for defaulters. Key Words: Tax, Tax system, Deterrent, Tax Measures, Tax Returns, Tax Liabilit

Stock Market Reaction to Election Cycles: The Nigerian Experience

This study seeks to unravel the relationship between national electoral events and industry’s stock market returns using the various presidential elections in Nigeria. The study adopts the traditional Market Model (MM) and testing with the Cumulative Abnormal Return (CAR) approach on the daily market data from the Nigerian Stock Exchange. Evidences abound that banking and Petroleum sector decreases before and increases after all elections. With the same trend for other sectors such as Conglomerates stock prices which oscillated in the same direction for the1999 and 2003; Brewery took their turn 1999 and 2011 while building sector experienced this event effect in 1999, thereby revealing industry connectivity with political activities. This manifests as their stock returns tend to reduce generally before and increase after election periods. We therefore recommend the depoliticization of public policies through strict adherence to corporate governance codes and strengthening of public institutions. This will put a check on the political manoeuvrings of the economy by boosting investors’ confidence on the market regardless of electoral activities and power swings. More importantly, for those stocks that experiences increase in value after election it is a better time to sell those portfolios and buy these stocks that experience loss in value at a post-election window.                                                            &nbsp