cryptography

What is cryptography?.
Cryptography is the science of using the mathematics to encrypt and decrypt data. Cryptography
enables you  to store sensitive information or transmit it across the insecure networks(like the internet) so that
cannot be read by anyone except the intend recipient.
While cryptography is the science of securing data, cryptanalysis is the science of analyzing and
breaking secure communication. Classical cryptanalysis involves an interesting combination of analytical
reasoning, application of mathematical tools, pattern finding, patience, determination, and luck.
Cryptanalysts are also called attackers.


How does cryptography work?.
 

A cryptographic algorithm, or cipher, is a mathematical function used in the encryption and decryption

process. A cryptographic algorithm works in combination with a key—a word, number, or phrase—to encrypt the

plaintext. The same plaintext encrypts to different ciphertext with different keys. The security of encrypted data

is entirely dependent on two things: the strength of the cryptographic algorithm and the secrecy of the key. A

cryptographic algorithm, plus all possible keys and all the protocols that make it work comprise a cryptosystem

Cryptology embraces both cryptography and cryptanalysis


Encryption and Decryption techniques.

Data that can be read and understood without any special measures is called plaintext or cleartext. The

method of disguising plaintext in such a way as to hide its substance is called encryption. Encrypting plaintext

results in unreadable gibberish called ciphertext. You use encryption to ensure that

information is hidden from anyone for whom it is not intended, even those who can see the encrypted data. The

process of reverting cipher text to its original plaintext is called decryption.

 

                           Figure 1. Encryption and Decryption