CRYPTOGRAPHY

Cryptography is the study of secure communications techniques that allow only the sender and intended recipient of a message to view its contents. The term is derived from the Greek word kryptos, which means hidden.In Cryptography the techniques which are use to protect information are obtained from mathematical concepts and a set of rule based calculations known as algorithms to convert messages in ways that make it hard to decode it.

These algorithms are used for cryptographic key generation, digital signing, verification to protect data privacy, web browsing on internet and to protect confidential transactions such as credit card and debit card transactions. 

Techniques used For Cryptography: In today’s age of computers cryptography is often associated with the process where an ordinary plain text is converted to cipher text which is the text made such that intended receiver of the text can only decode it and hence this process is known as encryption. The process of conversion of cipher text to plain text this is known as decryption. 

Features Of Cryptography :

1. Confidentiality: Information can only be accessed by the person for whom it is intended and no other person except him can access it.
2. Integrity: Information cannot be modified in storage or transition between sender and intended receiver without any addition to information being detected.
3. Non-repudiation: The creator/sender of information cannot deny his intention to send information at later stage.
4. Authentication: The identities of sender and receiver are confirmed. As well as destination/origin of information is confirmed.

Applications Of Cryptography:  Cryptography is widely utilized in computer security, particularly when creating and maintaining passwords. When a user logs in, their password is hashed and compared to the hash that was previously stored. Passwords are hashed and encrypted before being stored. In this technique, the passwords are encrypted so that even if a hacker gains access to the password database, they cannot read the passwords.

1. Electronic signatures serve as the digital equivalent of a handwritten signature and are used to sign documents. Digital signatures are created using cryptography and can be validated using public key cryptography. In many nations, electronic signatures are enforceable by law, and their use is expanding quickly. 
2. End-to-end encryption is used to protect two-way communications like video conversations, instant messages, and email. Even if the message is encrypted, it assures that only the intended receivers can read the message. End-to-end encryption is widely used in communication apps like WhatsApp and Signal, and it provides a high level of security and privacy for users.
3. Protection against attacks: Cryptography aids in the defense against various types of assaults, including replay and man-in-the-middle attacks. It offers strategies for spotting and stopping these assaults.