Cryptography in network security is the science of using mathematics in writing the secret code i.e. to encrypt(data transmit into unreadable format) and decrypt(unreadable data reverse transmitted into readable format) the data.
It is derived from the Greek words – Krypto means hidden and graphos mean writing.
Cryptography in network security is a need while communicating over an untrusted medium such as a network or an Internet. It is the process of protecting the information from adversary eaves dropper by transforming it (encrypting) into an unreadable format (cipher text) and then retransforming it (decrypting it into readable original text (plain text).
In the above figure of ‘Cryptography’, we have specified about Eve. An Eve is an enemy who attacks your data for the following various reasons:
- Eve may read and try to decrypt your message.
- Eve may try to get the key that was used to encrypt and then try to decrypt all messages with the same key.
- Eve may change the message sent by raja into another message in such a way that rani will have the feeling, after she get the changed message, that it was message form raja.
- Eve can pretend to be raja and communicates with rani in such a way that rani thinks that she is communicating with raja.
- Quantum cryptography
- Elliptic curve cryptography
Advantages of Cryptography
- Cryptography provides secrecy during communication by hiding words.
- Cryptography protects ordinary commerce and ordinary people. Therefore, as our home is to protect our private property, similarly cryptography is to protect our private information.
- Cryptography is used to secure the on-line network communications.
- Cryptography can protect e-mail messages, credit/debit card information, and any corporate data.