Types of Cryptography

1. Secret Key Cryptography (Symmetric Cryptography)

2. Public Key Cryptography (Asymmetric Cryptography)

3. Hash Functions

1. Secret Key Cryptography (Symmetric Cryptography):

Secret Key Cryptography, also known as symmetric cryptography, encrypts data with a single key. Because symmetric cryptography uses the same key for both encryption and decryption, it is the simplest kind of cryptography.

The cryptographic method encrypts the data using the key in a cypher, and when the data has to be retrieved again, a person entrusted with the secret key can decode the data. Secret Key Cryptography may be used on both in-transit and at-rest data, although it is most often employed on at-rest data since revealing the secret to the message’s receiver might lead to compromise.

Secret-key or symmetric-key encryption algorithms generate a predetermined number of bits known as a block cypher with a secret key that the creator/sender uses to encrypt data and the receiver uses to decrypt it.

It is written as P = D(K,E( P) )

Where,

K = Encryption and decryption key

P = Plain text

D = Decryption

E§ = Encryption of plain text

Some of the examples of Secret Key Cryptography are as follows:

• AES
• DES
• Caesar Cipher

2. Public Key Cryptography (Asymmetric Cryptography):

The Public Key to encrypt data, cryptography, also known as asymmetric cryptography, employs the use of two keys. The first key is used for encryption, while the second key is utilized to decode the communication.

One key is kept secret and is known as the “private key,” while the other is released openly and may be used by anybody, therefore the “public key.” The keys’ mathematical relationship is such that the private key cannot be deduced from the public key, while the public key can be deduced from the private key. The private key should not be disseminated and should be kept only by the owner. Any other entity can be granted the public key.

Public-key or asymmetric-key encryption algorithms encrypt information with a public key associated with the creator/sender and decode that information with a private key known only to the originator (unless it is exposed or they want to share it).

It is written as P = D(Kd,E(Ke,P)).

Where,

Ke = Encryption key

Kd = Decryption Key

D = Decryption

E(Ke,P) = Plain text encryption using an encryption key

P = Plain text

Some of the examples of Private Key Cryptography are as follows:

• ECC
• Diffie-Hellman
• DSS

3. Hash Functions:

Hash functions are one-way, irreversible functions that secure data at the expense of not being able to recover the original message. Hashing is a method of converting a given string into a set length string. A decent hashing algorithm will provide distinct outputs for each input. The only method to crack a hash is to test every conceivable input until you obtain the same hash. A hash can be used to hash data (for example, passwords) and in certificates.

Some of the most well-known hashing algorithms are as follows:

• MD5
• SHA-1
• SHA-2 family which includes SHA-224, SHA-256, SHA-384, and SHA-512
• SHA-3
• Blake 2
• Blake 3
• Whirlpool