Cryptography

It is the practice of concealing information from unwanted entities. Moreover, it is a technique of securing information systems and communication channels with mathematical algorithms or codes so that only allowed entities can understand and process it. And it is the study of secure communication techniques that enables only the sender and the recipient of a message to access its content through concealment or encryption procedures. Furthermore, encryption is the process of scrambling ordinary text message into intelligible text referred to as ciphertext and then back to its plaintext form. Besides, it involves the obfuscation of information in images and other multimedia using different techniques of concealment.

The fundamental objectives or services of cryptography are mainly the following:

• Confidentiality: protects unauthorized access or disclosure of information
• Integrity: concerns with protection of unintended modification or tampering of information
• Authentication: It is the process of proving or confirming the identities of a sender and a receiver
• Nonrepudiation: Protects either party (sender or receiver of a message) from denying an activity they have done

The most common application of cryptography is when transmitting sensitive digital data across networks such as email and other plaintext messages. In this case, the use of encryption algorithms play crucial role in safeguarding the message. There are different types of cryptographic algorithms that organizations and individuals can use to secure their messages. The following are the three major types of cryptography in use in businesses of all size today:

• Symmetric Cryptography: a cryptosystem in which the sender and the receiver of a message use the same encryption and decryption key. It is scalable, simpler and faster encryption technique than asymmetric algorithms. However, the challenge with symmetric cryptography is the key exchange process where the receiver and sender obtain the shared key through insecure out-of-band channels.
• Asymmetric Cryptography: a cryptosystem that uses a pair of keys to undertake the encryption process. Unlike symmetric algorithms, it employs secure key exchange among communicating parties. However, it is complex, less scalable and less secure than symmetric techniques.
• Hash Function Algorithm: A cryptographic algorithm that involves no usage of encryption key. Unlike encryption algorithms, hash function is one-way function and it is impossible to drive the content of a message from hash values.