What is SHA3-512 Hashing?

SHA3-512 is a cryptographic hash function that belongs to the SHA-3 (Secure Hash Algorithm 3) family. It produces a 512-bit (64-byte) hash value, typically expressed as a 128-character hexadecimal number.

Key characteristics of SHA3-512:

It's a one-way function - you cannot reverse the process to get the original text from the hash
The same input will always produce the same output hash
Even a small change in the input will produce a completely different hash
It was designed by Guido Bertoni, Joan Daemen, Michaël Peeters, and Gilles Van Assche as the Keccak algorithm
It was selected by NIST in 2012 as the winner of the SHA-3 competition
It uses a completely different internal structure (sponge construction) than SHA-2, providing algorithm diversity
It provides the highest security margin in the SHA-3 family
It's resistant to attacks that might potentially threaten SHA-2 algorithms

Example

Original text

Hello World

SHA3-512 Hash

3d58a719c6866b0214f96b0a67b37e51a91e233ce0be126a08f35fdf4c043c6126f40139bfbc338d44eb2a03de9f7bb8eff0ac260b3629811e389a5fbee8a894

Common uses of SHA3-512

Applications requiring maximum security and resistance to quantum computing attacks
Systems that need algorithm diversity (not relying solely on SHA-2 family)
Storing password hashes in highly security-critical systems
Digital signatures for extremely sensitive documents
High-security blockchain and cryptocurrency applications
Military and government-grade secure communication protocols

SHA3-512 vs. Other Hash Functions

Feature	SHA3-512	SHA3-256	SHA-512
Hash length	512 bits (128 hex chars)	256 bits (64 hex chars)	512 bits (128 hex chars)
Internal structure	Sponge construction	Sponge construction	Merkle–Damgård construction
Security	Highest security margin in SHA-3 family	Strong security, smaller output	Highest security margin in SHA-2 family
Speed	Slowest of the compared algorithms	Faster than SHA3-512	Faster than SHA3-512 on most platforms
Resistance to quantum attacks	Very high	High	Moderate

SHA-3 Family

SHA3-512 is part of the SHA-3 family, which includes:

SHA3-224: Produces a 224-bit hash
SHA3-256: Produces a 256-bit hash
SHA3-384: Produces a 384-bit hash
SHA3-512: Produces a 512-bit hash (this algorithm)
SHAKE128 and SHAKE256: Extendable-output functions (XOFs) that can produce hash outputs of any desired length

When to Choose SHA3-512

Choose SHA3-512 when:

You need the maximum security margin available
Processing speed is less important than security
You're designing systems that need to remain secure for many years into the future
You're concerned about potential advances in quantum computing
You want algorithm diversity in addition to your existing SHA-2 implementations

Security Note:

SHA3-512 provides the highest security margin in the SHA-3 family. While it's somewhat slower than SHA-512 from the SHA-2 family, it offers the advantage of using a completely different internal structure, which provides valuable algorithm diversity. This makes it an excellent choice for the most security-critical applications, especially those that need to remain secure against future advances in cryptanalysis and quantum computing.

How SHA3-512 Hashing Works

SHA3-512 hashing follows these steps:

The input text is converted to binary data
The algorithm uses a sponge construction with the Keccak-f[1600] permutation function
The data is "absorbed" into the sponge state (a 5×5×64 bit state array)
The permutation function is applied multiple times, mixing the input data thoroughly
The output is "squeezed" from the state until the desired 512 bits are produced
The hash is typically represented as a 128-character hexadecimal string