# Cryptography

Learn about the cryptography, types of cryptography, techniques used for cryptography, advantages of cryptography, and how does cryptography work?
Submitted by Vaishnavi Srivastava, on January 23, 2022

The study of encrypting and decrypting data to prevent unauthorized access is known as cryptography. The safe transfer of digital data between willing parties is made possible by cryptography. It's used to keep firm secrets safe, secure classified information, and protect sensitive data from fraud, among other things. The words crypto and graph both mean "hidden" and "writing." A plaintext message is turned to the ciphertext in cryptography.

## Types of Cryptography

There are 3 major types of Cryptography:

1. Symmetric Key Cryptography is an encryption scheme in which the sender and receiver of a message encrypt and decode messages using a single common key. Symmetric Key Systems are faster and easier to use, but they have the drawback of requiring the sender and receiver to exchange keys securely. Data Encryption System is the most widely used symmetric key encryption system (DES).
2. Hash Functions: This algorithm does not make use of any keys. A hash value with a fixed length is calculated based on the plain text, making it impossible to reconstruct the plain text's contents. Hash functions are used by several operating systems to encrypt passwords.
3. Asymmetric Key Cryptography: This system encrypts and decrypts the information using a pair of keys. Encryption is done with a public key, and decryption is done with a private key. The terms "public key" and "private key" are not interchangeable. Even if everyone knows the public key, the intended receiver can only decode it because he is the only one who knows the private key.

## How does Cryptography work?

Cryptographic algorithms are at the heart of how cryptography works. To encrypt text, cryptographic algorithms or ciphers are mathematical functions paired with keys such as phrase, number, word, and so on. The power of the cryptographic methods and the level of key secrecy determine the effectiveness.

A cryptosystem's effectiveness is boosted by multiple complex combinations of algorithms and keys.

## Techniques used for Cryptography

1. Simple Codes: This category encompasses any method of writing a message side by side that makes it difficult for others to read. This entails writing in a different alphabet.
2. Symmetric Encryption: Symmetrical encryption is a type of encryption that uses only one key to encrypt and decrypt electronic data (a secret key). Symmetrical encryption techniques like substitution ciphers exist, but current symmetric encryption can be far more sophisticated.
3. Asymmetric Encryption: Public-key cryptography is another name for asymmetric encryption. Asymmetric key encryption aids in the resolution of the symmetric key cryptography key exchange problem. In asymmetrical encryption, two keys are utilized to encrypt plain text.
4. Stenography: Steganography is a technology that allows a message to be hidden inside another message. People employed invisible ink, minute changes, and other means to hide messages in the past.
5. Hashing: Hashing is a cryptographic technique for converting any type of data into a single string. Any data can be hashed using a hashing algorithm, regardless of its size or type.

1. Confidentiality Encryption techniques can protect information and communication against unauthorized disclosure and access.
2. Authentication MAC and digital signatures are cryptographic techniques that can safeguard information from spoofing and forgeries.
3. Data Integrity Cryptographic hash functions serve an important role in ensuring data integrity for users.
4. Non-repudiation the digital signature provides a non-repudiation service to protect against any disputes that may occur as a result of the sender's refusal to pass on a communication.