Cryptography is the study of securing data by transforming it into a form that unintended recipients cannot understand. In cryptography, the original human-readable message (called plain text) is converted with the help of an algorithm or a series of mathematical operations to look gibberish to an unsuspecting observer. This gibberish is called ciphertext.

Types of Cryptography Techniques:

1.Symmetric Key Cryptography

This is a type of cryptography where both the sender and the receiver utilize a common key for message encryption and decryption.

Symmetric keys are quite fast but the challenge is sharing the key between a large number of people.

Examples of symmetric key cryptography include AES (Advanced Encryption Standard), DES, Triple DES, RC2, RC4, RC5, IDEA, Blowfish, stream cipher, block cipher, and so on..

2.Asymmetric Key Cryptography

In this form of cryptography, a pair of keys is used to encrypt and decrypt information. 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, only the intended receiver can decode a message because he is the only one who has the private key.

Asymmetric keys can ensure secure key distribution, but it uses a lot of resources. It is also quite slow and involves heavy mathematical operations.

Examples of asymmetric key cryptography include RSA, DSA, PKCs, Elliptic Curve techniques, and so on

3.Hash Function

A hash function is a cryptographic technique that takes inputs of arbitrary length and provides output of a fixed length. The hash function is also considered as a mathematical equation that takes seed (numeric input) and produces an output that is commonly referred to as a hash or message digest. This system operates in a one-way  manner and does not require any key. It is also considered to be the foundation of modern cryptography.

Examples of hash functions include Message Digest 5 (MD5), SHA (Secure Hash Algorithm), SHA128 and SHA256, and so on. These are aimed at protecting passwords and private data.

Hybrid cryptography is a mode of encryption that merges two or more encryption systems. It incorporates a combination of asymmetric and symmetric encryption to derive benefit  from the strengths of each. The approach takes advantage of public-key cryptography for sharing keys and the speed of the symmetric encryption for encrypting messages.

A hybrid encryption scheme combines the ease of use of an asymmetric encryption scheme with the effectiveness of a symmetric encryption technique.

To encrypt a message first generate a symmetric key and then encrypt the data.Then the person to whom we wish to send the message will share her public key and keep the private key a secret. After this, encrypt the symmetric key using the public key of the receiver and send the encrypted symmetric key to the receiver.

To decrypt a message the receiver decrypts the encrypted symmetric key using her private key and gets the symmetric key needed for decryption and then the receiver uses the decrypted symmetric key to decrypt the message.

ADVANTAGES:

• Provides a high level of security Hybrid encryption is a combination of symmetric    encryption and asymmetric encryption so It provides high security as compared to other techniques.
• Transmission of data becomes secure. Just  as  data  security  is  ensured  on  all devices,  encrypting  data  also  provides  security benefits during transmission.