Cryptography

Cryptography is the set of protocols and algorithms for information protection and verification. There are three widely used concepts in Cryptography that are used to achieve data verification, integrity and confidentiality. These are encryption, hashing and salting.

Encryption

Encryption scrambles data so its unreadable by unintended parties. Encryption is two way. When you encrypt something it will be decrypted and used. To encrypt data you normally use a cipher which is an algorithm used to perform the encryption and decryption.

Some popular encryption algorithms include:

AES

AES stands for Advanced Encryption Standard. It is a symmetric encryption algorithm. In symmetric encryption each party has its own key that can both encrypt and decrypt. AES is a common algorithm with SSL/TLS since it is faster and can be used to communicate efficiently.

RSA

RSA is a public key asymmetric encryption algorithm. Asymmetric means there are two different keys. A user publishes a public key. Anyone can use it and send messages to the user. Only user with the private key can read those messages.

Blowfish

Blowfish is also a symmetric cipher. It is mainly used for securing passwords in password management tools.

Hashing

Hashing is the process of creating a map key of fixed length for quick access of data. While encryption protects data that needs to be transferred across a network, hashing can be used to verify that the data was not altered. Each hashing algorithm outputs data at a fixed length. The output is called a hash value, message digest or checksum.

E.g. Here are a few:

Hash	Digest Size
MD4	16
MD5	16
SHA1	20
SHA224	28
SHA256	32

The two most popular hashing algorithms are:

MD5

MD5 is not secure and is proven to suffer vulnerabilities. But if the goal is to create a unique hash for lookup it could be used.

SHA

SHA stands for Secure Hashing Algorithm. It is teh most widely used in SSL/TLS cipher suites. SHA1 is deprectaed in favor of SHA2 which is also known as SHA-256.

Salting

Salting is often used in password hashing. A unique value is stored at the end of a password. This value is known as salt. This makes it virtually impossible to apply brute force to decrypt the password. Using a random salt guarantees that no two passwords have the same hash value hence making it harder to decipher.