Todays, banks are using very complex IT infrastructures for their operations. This includes hardware, software, networking equipments and data centres. Many banks have also gone for data warehousing and data mining tools for their decision making. To safeguard these physical and IT assets and the data, it is necessary that evey banker who deals with information technology should have the adequate knowledge of IT security and its implications. This book is meant as courseware for the "Certificate Exam in IT Security" being offered by the Indian Institute of Banking & Finance. This book provides an overview of IT security in Banking Institutes. The contents of the book will be found useful by all those who are invoilved in IT Security in banks and students who are pursuing academic courses on the subject.