Which algorithm uses a completely different hash generation approach than SHA-2?

SHA-3 employs a fundamentally different hash generation approach compared to SHA-2. While SHA-2 is based on the Merkle-Damgård construction, SHA-3 utilizes a completely different structure known as the sponge construction.

This sponge construction allows SHA-3 to absorb input data and then squeeze out the hash output, providing greater flexibility in terms of output size and security. This difference not only changes how the hash is generated but also enhances resilience against certain types of cryptographic attacks that may affect other hashing algorithms.

In contrast, SHA-1, SHA-4, and SHA-5 are either iterations or theoretical extensions based on earlier designs like SHA-2, and they do not represent this significant variation in hashing methodology represented in SHA-3. Understanding these differences is crucial for selecting the appropriate hash function for various cybersecurity applications.