2.1 IntroductionCryptography is an interesting field in the world of computer security. This situation has been reinforced by the increase in computer attacks emanating from the Internet. With large and confidential data transferred over the Internet, its security must be ensured. It is for this reason that encryption techniques are continually evolving. Since hackers are computer experts eager to access personal data on the Internet, computer security experts have also made sure to offer products to combat and stay one step ahead of hackers. With the availability of good network infrastructure, many people are turning to the Internet to send and store their information. Additionally, with the development and emergence of cloud computing, it is imperative that individuals and organizations are responsible for the security and confidentiality of data transferred. Email messages are one of the main targets for attackers on the web. Internet. Email usage has increased over the years and phishing attacks have become more frequent and more targeted, leading to a dramatic increase in computer fraud. All these developments require the implementation of good security measures. Cryptography has therefore received greater importance in the world of computer security. Web 2.0 applications that have been aggressively deployed have created an increase in complex and secure cryptographic techniques that are difficult to crack.2.2 DefinitionCryptography is the concept and process of hiding information. The process of converting data into a disguised form so that it is difficult to understand is called encryption. The data resulting from converting plaintext into unreadable gibberish is called ciphertext. T...... middle of paper ......The text was written with confusing symbols so that users could not decipher the message. It wasn't until 5 BC that the Spartans, known for their warlike nature and bravery in battle, found a way to send secret messages without their enemies knowing what was happening. They developed a device called a scytale. The process of preparing the message involves wrapping a narrow strip of parchment or leather around the scytale, then the message is written on it (Jacobson et al, 2004). When the tape is unrolled and transported to the recipient, it displays a collection of letters on it that have no meaning. At the receiving end, the strip is rewound with a scytale of the same diameter. This represents a transposition cipher - where the letters are not changed but only their positions. This technique is still used by many people today.