Networking

Cryptography is derived from the Greek words kryptos meaning “hidden” and graphien, meaning “to write/study”. The process of making and using codes to secure the transmission of information is called cryptography. Before modern era cryptography was synonymous to encryption but today cryptography is heavily based on mathematical theory and computer science practice. Cryptography today deals with the ways to transfer information in such a manner that no one beside the recipients can read what was actually sent and also more advanced crypto techniques deal with ensuring that the information being transferred has not been compromised in the transit. Cryptanalysis is the process of obtaining the original message (Plaintext) from an encrypted message (ciphertetext) without knowing the algorithms and keys used in encryption. Crypto is a tool that can be used in both good and bad ways. Some of the good crypto uses are:
• Protecting the location of our troops in war zone
• Protecting the nuclear launch codes
• Protecting national security information
• Protecting research data
• Protecting a new research idea

2. Cryptographic Algorithms
Cryptographic Algorithms are the set of rules used to encipher and decipher messages in a cryptographic system. It is a process which uses encryption allowing only authorized party to access the information. Cryptographic algorithms are grouped in two categories:
• Symmetric-key Cryptography
• Asymmetrical -key Cryptography

2.1. Symmetric key Cryptography
Symmetric Key Cryptography uses the same cryptographic keys to encipher and decipher the message using symmetric encryption. The sender and receiver share the same key. Symmetric encryption method use mathematical operations that can be programmed into extremely fast computing algorithms which makes encryption and decryption of the messages quick even with the small computers. With the Symmetric encryption the secret key should be send through different channel or band to