The origins of modern cryptography date back approximately 3000 years. The procedures used to encrypt messages before 1900 were primitive compared to modern approaches, but they are easy to understand and provide a good basis to study the more complicated methods. In recent times, especially after the emergence of telecommunication equipment, more complex encryption methods have become necessary. Today, an exorbitant amount of information is transmitted via the internet. Millions of people use websites for their banking activities causing the transmission of sensible data via networks where the precise routing of data is not always known and data may be manipulated or stolen.