The use of credit cards has become a way of life in many parts of the world. Credit cards have also created many new opportunities for criminal activity. It is in this light that organizations such as VISA International have explored a variety of security alternatives by constantly reviewing security measures that may be applied to cards and devote considerable resources to the maintenance of security systems and programmes. These programmes mandated by the association, include uniform card standards, security standards for manufactures, embossing and encoding of cards, standards for mailing the cards and credit background investigations of applicants. These standards assist investigators in examining counterfeit cards and distinguish a counterfeit card from a genuine card. The constant reviewing of security features and methods by the association is to create a card that is technically difficult to alter or counterfeit. / Criminology / M.Tech. (Forensic Investigation)

The use of credit cards has become a way of life in many parts of the world. Credit cards have also created many new opportunities for criminal activity. It is in this light that organizations such as VISA International have explored a variety of security alternatives by constantly reviewing security measures that may be applied to cards and devote considerable resources to the maintenance of security systems and programmes. These programmes mandated by the association, include uniform card standards, security standards for manufactures, embossing and encoding of cards, standards for mailing the cards and credit background investigations of applicants. These standards assist investigators in examining counterfeit cards and distinguish a counterfeit card from a genuine card. The constant reviewing of security features and methods by the association is to create a card that is technically difficult to alter or counterfeit. / Criminology and Security Science / M.Tech. (Forensic Investigation)

關於信用卡詐欺風險管控的研究，係非常專業的問題，除了瞭解信用卡各項作業程序外，必須親自參與實務上的管控經驗，才能充分瞭解現有市場上，信用卡詐欺所發生之原因、詐欺模式、手法與趨勢，也唯有做到理論結合相關實務管控經驗，才能研究出有效的防制策略。目前在實務上防制信用卡詐欺方面，由本文中可發現，業者與警政單位在處理信用卡風險管控與詐欺案件時，有非常多的盲點與困難，也突顯出其專業能力上之不足，因此導致信用卡詐欺問題之嚴重。 在防制信用卡詐欺研究當中，筆者第一次嘗試將信用卡實務運作之模式貢獻出來 ; 以過去到現在的實務經驗，將信用卡所發生的案例，來探究其發生的原因 ; 以運用分析的方法，來建立各項風險管控措施 ; 以闡釋各項業務之作業風險，來遏止風險損失之發生 ; 以紮實的教育訓練教材，讓特約商店做好第一道的防衛 ; 以科學的統計方法，來研究防衛參數與增加偵測系統的防衛效能 ; 以實務管控的經驗，來遏止其犯罪手法的翻新 ; 以實際案件調查的經驗，來瓦解詐欺集團的組織，所以必須瞭解信用卡整體運作的關係與詐欺手法，才能深入瞭解各項風險管控問題，並結合預防作業、偵測系統、調查作業的功能，方能充分發揮信用卡業務詐欺風險管控的效能。 除了建立完整的風險管控作業之外，在第六章之建議事項中，就主管機關、司法機關、警政單位、發卡業者、收單業者、特約商店、持卡人與國際組織等方面 ; 提出個人具體之建言，藉以喚起社會各界對信用卡詐欺問題之重視，以推動損害防阻之功，徹底解決當前所發生之信用卡詐欺問題。 / The research on credit card risk management is a specialized field. Besides the need of understanding the various operational processes, personal involvement’s and practical experiences in respect of credit card risk management are essential in order to fully appreciate the reason for credit card frauds in the current market. An effective credit card fraud prevention strategy consists of the theoretical aspects and practical experiences of credit card fraud management. Based on this paper, it appears that strategies of credit card fraud prevention are solely lacking in the current market. This is because the business sectors and police department encounters numerous ‘blind spots’ and problems when tackling with fraud issues. Also, the lack of professionalism in control and prevention strategies resulted in serious credit card fraud issues. In this research, the author would attempt to showcase for the first time the credit card’s practical working models;1) to try to investigate and understand the reasons for credit card frauds by reviewing past and present real life cases; 2) to develop various risk management methodologies via credit card risks analysis; 3) to explain the various businesses’ operational risks to reduce if not prevent loss occurrences; 4) to constantly upgrade /educate the merchant banks with solid training programmers to make them an effective first line of defense; 5) to employ scientific statistical methods to aid in the research of any defensive mechanisms as well as to increase the effectiveness of early detective systems, if any; 6) to make use of practical credit card risk management experiences in order to prevent repeat offences; 7) to utilize real life investigative experiences to dissolve credit card syndicates and/or groups. Therefore, know the relation of whole operation of credit card and modus operandi could understand in depth of every risk management issue, and combine the function of preventing operation, detection system, investigation process can be fully developed efficiency for credit card risk management. In addition to establish sophisticated a developing risk management methodology, the author has directed his personal opinions to the various industry players such as the regulatory bodies, policing units, credit card issuers, acquiring banks, merchant banks and credit card users. In chapter 6 of the recommendations, he attempts to draw the public’s attention on the seriousness of credit card frauds that exists in our society. He also hopes to completely eradicate the issues of credit card frauds by actively promoting the risk prevention methodology of credit card frauds.

LL.M. / Despite payment cards being of a fairly recent origin,1 these instruments of payment play an increasingly significant role in commerce. With reference to credit cards, Cornelius already in 2003 stated: “They fulfil various functions that are increasingly important at a time that ecommerce is taking off at a tremendous pace.”2 Similarly criminals continuously use more inventive and technologically advanced methods to commit fraud, including counterfeit card fraud. Is the South African criminal law, however, keeping up? The aim of this study is to investigate whether the various activities which form part of the criminal business value chain relating to counterfeit card fraud, with specific reference to bank payment cards, are sufficiently criminalised in South Africa or whether the inability of our criminal law to address the challenges posed by this crime type necessitates the introduction of further legislation. In the first part of the dissertation the South African common and statutory criminal law is investigated in some depth to establish the applicability thereof on the activities forming part of the criminal business value chain relevant to counterfeit card fraud. The appropriateness of certain statutory provisions is questioned and recommendations are made to amend current legislation. An argument is also advanced for further development of the common-law offence of theft to include identity theft and the unlawful copying and subsequent use of data. Brief reference is made to the international situation. Chapter 2 is an introduction to bank payment card fraud in South Africa focusing on the most prevalent forms thereof being card-not-present fraud and counterfeit card fraud. Reference is made to the manner in which offences related to counterfeit card fraud are currently approached in our criminal courts and the limited impact prosecutions has on the prevalence of this fraud type.

In this thesis, a comparison of three different pre-processing methods for imbalanced classification data, is conducted. Variational Autoencoder, Random Under-Sampling Boosting and a hybrid approach of the two, are applied to three imbalanced classification data sets with different class imbalances. A logistic regression (LR) model is fitted to each pre-processed data set and based on its classification performance, the pre-processing methods are evaluated. All three methods shows indications of different advantages when handling class imbalances. For each pre-processed data, the LR-model has is better at correctly classifying minority class observations, compared to a LR-model fitted to the original class imbalanced data sets. Evaluating the overall classification performance, both VAE and RUSBoost shows improving classification results while the hybrid method performs worse for the moderate class imbalanced data and best for the highly imbalanced data.

Today, the use of one's bank card to pay or withdraw money is common. Modern technology provides us with the convenience of instant transactions at the automated teller machine or point of sale but unfortunately, it has also brought the reality and risk of card skimming and counterfeit card fraud. Criminals have become very efficient and technologically advanced in skimming and counterfeiting cards, to such an extent that counterfeit card fraud has become a significant threat to the public, banking, retail and business in South Africa. Counterfeit card fraud is a complex, multi-faceted crime, requiring specific skills and knowledge of card counterfeiting methods from police and bank investigators. The scope of its investigation is wide. It includes different crime scenes and offenders, sophisticated equipment and various aspects that need to be identified positively. Investigators find it difficult to identify perpetrators and certain aspects unique to this crime and, as a result, many investigations are unsuccessful. This research endeavours to establish what identification methods are available to investigators and which are effective. / Police Practice / M. Tech. (Forensic Investigation)