Page 207 - Cyber Defense eMagazine Annual RSA Edition for 2024

SHA-2 (SHA-256, SHA-384, SHA-512): A family of stronger hashing algorithms released in 2002. These
offer significant improvements in security over MD5 and SHA-1.

o Pros: Considered collision resistant for the foreseeable future. Different variants (SHA-256, SHA-
384, SHA-512) offer varying levels of security and output hash lengths.
o Cons: Can be computationally expensive compared to older algorithms like MD5. SHA-384 and
SHA-512 produce longer hash outputs which might not be ideal for all storage scenarios.

The Move Towards SHA-3:

o SHA-3: The latest addition to the SHA family, released in 2015. It uses a completely different
cryptographic design compared to SHA-2 for enhanced security.
o Pros: Considered the most secure hashing algorithm from NIST as of today. Resistant to
currently known attacks.
o Cons: Newer algorithm, so hardware and software support might be less widespread
compared to older options.

Choosing the Right Algorithm:

The choice of hashing algorithm depends on the specific application and its security needs. For critical
tasks like password storage or digital signatures, using a strong and collision-resistant algorithm like
SHA-256 or SHA-3 is recommended. For less critical tasks where speed is a priority, an older algorithm
like MD5 might be used for initial checks, followed by verification with a stronger algorithm.

Remember, the world of cryptography is constantly evolving, and new vulnerabilities might be discovered
in existing algorithms. It’s important to stay updated on the latest recommendations and choose hashing
algorithms based on their current security posture.

Is Hashing a one-way Function?

Yes, hashing is a one-way function. This means you can easily take data and create a hash from it, but
it’s very difficult, practically impossible, to do the opposite - turn the hash back into the original data.

Here’s why:

• Avalanche Effect: Most secure hashing algorithms are designed with an “avalanche effect.” This means
that a small change in the original data (like flipping a single bit) results in a significant change in the hash
output. Imagine the hashing recipe is like a complex mousetrap. A tiny change in how you set the trap
(data) can completely alter the outcome (hash).
• Fixed-Size Output: Hash functions compress data into a fixed-size output (hash). This output is much
shorter than the original data, making it mathematically challenging to recreate the original data from just
the short hash. It’s like trying to rebuild a house from just its tiny address.

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