> For the complete documentation index, see [llms.txt](https://www.x509.wiki/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://www.x509.wiki/cryptography/hashing-algorithms.md).

# Hashing Algorithms

A hashing algorithm is a mathematical function that converts input data of any size into a fixed-length string of characters, which is typically a sequence of letters and numbers. This output is known as a hash value or digest.

## What is a Collision? <a href="#what-is-a-collision" id="what-is-a-collision"></a>

A collision in hashing occurs when two distinct pieces of data produce the same hash value using a hashing algorithm12. This can be problematic because the primary goal of a hashing algorithm is to uniquely represent different data inputs.

## What is a MAC? <a href="#what-is-a-mac" id="what-is-a-mac"></a>

Message Authentication Code (MAC): In cryptography, a MAC is a short piece of information used to authenticate a message and ensure its integrity. It verifies that the message has not been altered and confirms the sender’s identity.

## How is a MAC different from an HMAC? <a href="#how-is-a-mac-different-than-an-hmac" id="how-is-a-mac-different-than-an-hmac"></a>

MAC: A general term for a code that verifies message integrity and authenticity, using either block ciphers or hash functions.

HMAC: A specific type of MAC that uses a cryptographic hash function and a secret key, offering stronger security properties.


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