Cryptography- Part 4
Hash functions are primarily used to provide integrity. Hashing and cryptography have a very close relationship.
A one-way function ensures that the same key can’t encrypt and decrypt a message in an asymmetric key system. A one-way function’s purpose is to ensure confidentiality. A one-way hashing algorithm produces a hashing value (or message digest) that can’t be reversed; that is, it can’t be decrypted.
Hashing provides encryption by using an algorithm without use any key. It is called one-way hash functions because there is no way to reverse the encryption.
A variable-length plaintext is hashed into a fixed-length hash value, which is usually called a message digest or a hash.
Collisions: This means that one or more documents use the common hash.
Hashing Algorithms Family
- Message Digest (MD): It is a family of one-way hashing algorithms that includes MD (obsolete), MD2, MD3 (not widely used), MD4, MD5, and MD6.
- Secure Hash Algorithm (SHA): This family is more secure, and widely used hashing algorithm. There are several versions of this algorithm.