What is Secure Hash Algorithm (SHA)? and what are the different types of Secure Hash Algorithm? And which ones are secure?
Secure Hash Algorithm (SHA) is widely used hashing algorithm to protect the integrity of organizational data. Moreover, secure Hash Algorithms (SHAs) are government standard hash functions promoted by the National Institute of Standard and Technology (NIST) and are specified in an official government publication known as Secure Hash Standard (SHS). Besides, it has successors namely SHA-1, SHA-2, and SHA-3, and it is also known as Federal Information Processing Standard (FIPS). NIST AND NSA (National Security Agency) designed the Secure Hash Algorithm (SHA). Furthermore, there are some secure and insecure SHAs and organization should only consider secure hash algorithms to protect data.
SHA-1 algorithm is considered no more secure and it is replaced by SHA-2 algorithm. SHA-2 is more secure, robust and safer hashing algorithm. And SHA-2 has the following variants that be used to protect data based on business requirements of organizations.
- SHA-224: It uses a truncated version of the SHA-256 has that drops 32 bits to generate a 224-bit message digest through a 512-bit block size.
- SHA-256: It generates a 25-bit message digest (MD) using a 512-bit block size
- SHA-384: It uses a truncated version of the SHA-512 hash that drops 128 bits to generate a 384-bit digest through a 1,024-bit block size
- SHA-512: It generates a 512-bit message digest using a 1,024-bit block size
The Secure Hash Algorithm (SHA) version 2 (SHA-2) and version (SHA-3) are government standard hash functions that are promoted by NIST. The most common types of secure hash algorithms (SHAs) are briefly discussed as follows:
- SHA-1: SHA-1 is a cryptographic hash algorithm which takes an input and generates a 160 bit has value or message digest.
- SHA-2: SHA-2 is a group of different hashing algorithms, namely SHA-224, SHA-256, SHA-384 and SHA-512 algorithm.
- SHA-3: The SHA-3 algorithm was developed as a replacement for the SHA-2 hash function. Moreover, SHA-3 offers the same variants and hash lengths using a different computational algorithm. SHA-3 delivers the same level of security as SHA-2 but slower than SHA-2.
SHA-2 and SHA-3 are secure hash algorithms, but SHA-1 is insecure hash function.