Origin
The Secure Hash Algorithm (SHA) series, including SHA-224, is part of the SHA-2 family, developed by the National Security Agency (NSA) and published in 2001 by the National Institute of Standards and Technology (NIST). SHA-224 was designed as a part of the U.S. Federal Information Processing Standards (FIPS).
Example Hash
An example hash of "Hello World" in SHA-224 might look like:
c4890faffdb0105d991a461e668e276685401b02eab1ef4372795047
Usage
SHA-224 is widely used in various security applications and protocols, including TLS and SSL, PGP, SSH, and IPsec, particularly for data integrity verification and authentication processes.
Development
SHA-224 was developed to provide an alternative to SHA-256 with a slightly reduced bit length, offering a balance between security and computational efficiency.
How It Works
SHA-224 employs a series of bitwise operations, logical functions, and modular additions to process the input data. It processes data in 512-bit blocks and outputs a 224-bit hash value.
Salt
While SHA-224 itself does not inherently use a salt (random data added to the input), it can be implemented with salting to enhance security against dictionary attacks.
Limitations
The main limitation of SHA-224 is its susceptibility to length extension attacks, although it's less vulnerable than SHA-1.
Particularities Compared to Other Algorithms
SHA-224 offers a shorter hash compared to SHA-256, which can be advantageous for saving space without significantly compromising security.
Computational Power/Cost
SHA-224 is computationally efficient, making it suitable for systems with limited resources while still providing robust security.
Resistance to Attacks
SHA-224 is resistant to common cryptographic attacks, including collision and pre-image attacks, though not as strong as SHA-256 or SHA-3.
Obsolescence
While SHA-224 is currently secure, the progression in computational power and cryptanalysis may eventually render it less effective.
Modern Alternatives
Modern alternatives like SHA-256 and SHA-3 offer enhanced security and are recommended for more critical security applications.
Compatibility
SHA-224 is compatible with most existing systems and protocols requiring cryptographic hashing, ensuring a wide range of applicability.
Conclusion
While SHA-224 is a reliable cryptographic hash function, its use should be considered in less critical applications. For enhanced security, newer algorithms like SHA-256 or SHA-3 are recommended.