# cryptographic hash function

> special class of hash function that has certain properties which make it suitable for use in cryptography

**Wikidata**: [Q477202](https://www.wikidata.org/wiki/Q477202)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Cryptographic_hash_function)  
**Source**: https://4ort.xyz/entity/cryptographic-hash-function

## Summary
A cryptographic hash function is a special class of hash function with properties that make it suitable for use in cryptography. It is used for cryptography and hashing, and is treated as a cryptographic primitive (a building block used in more complex cryptosystems). It is explicitly contrasted with a non-cryptographic hash function.

## Key Facts
- A cryptographic hash function is described as a “special class of hash function that has certain properties which make it suitable for use in cryptography.”
- It is used for **cryptography** and **hashing**.
- It is a **subclass of** both **hash function** and **cryptographic primitive**.
- It is the **opposite of** a **non-cryptographic hash function**.
- It has a Wikipedia title: **“Cryptographic hash function”** and a Commons category: **“Cryptographic hash function.”**
- It is associated with the topic’s main category: **Category:Cryptographic hash functions**.
- It is described by the source **Security Engineering: A Guide to Building Dependable Distributed Systems (2nd edition)** (Chapter 5; sections 5.3.1 and 5.6).
- It has identifiers including **golden_id: Cryptographic_hash_function-JPY88**, **Freebase ID: /m/028pgb** (publication date 2013-10-28), and **MathWorld ID: CryptographicHashFunction**.
- It has Stack Exchange tags including **https://crypto.stackexchange.com/tags/hash** and **https://stackoverflow.com/tags/cryptographic-hash-function**.
- It has sitelink_count **32** (as provided in the source material).

## FAQs
### Q: What is a cryptographic hash function used for?
A: It is used for cryptography and hashing. It is treated as a cryptographic primitive, meaning it serves as a building block for more complex cryptosystems.

### Q: How is a cryptographic hash function different from a non-cryptographic hash function?
A: A cryptographic hash function is a special class of hash function designed with properties suitable for cryptography. In the provided data, it is explicitly listed as the opposite of a non-cryptographic hash function.

### Q: Is a cryptographic hash function considered a cryptographic primitive?
A: Yes. It is classified as a subclass of “cryptographic primitive,” described as an established cryptographic algorithm used as a building block for more complex cryptosystems.

### Q: Where can I find reference material about cryptographic hash functions?
A: The entity is described by *Security Engineering: A Guide to Building Dependable Distributed Systems, 2nd edition* (Chapter 5; sections 5.3.1 and 5.6). It also has entries/tags across Wikipedia, Wikimedia Commons, and Stack Exchange.

## Why It Matters
Cryptographic hash functions matter because they are a foundational building block in cryptography. The source material classifies them as a cryptographic primitive—an established algorithm used to construct more complex cryptosystems—so they sit at the base layer of many security designs. They also matter because they are not just any hash function: they are explicitly described as a special class with properties that make them suitable for cryptographic use, and they are contrasted with non-cryptographic hash functions. This distinction is important in practice because “hashing” can refer to many techniques, but cryptographic contexts require hash functions with specific security-relevant properties. The ecosystem around cryptographic hash functions is broad and well-documented, spanning reference texts (e.g., *Security Engineering*), standard knowledge bases (Wikipedia/Wikimedia Commons), and practitioner Q&A communities (Stack Exchange tags). As a result, the term “cryptographic hash function” serves as a key organizing concept for understanding and navigating cryptographic systems and the hash-function families, constructions, and variants used within them.

## Notable For
- Being explicitly defined as a **special class of hash function** suitable for **cryptography** (not merely general-purpose hashing).
- Classification as a **cryptographic primitive**, i.e., a building block for more complex cryptosystems.
- Explicit conceptual contrast: **opposite of non-cryptographic hash function**.
- Strong documentation footprint across major references and community resources (Wikipedia/Commons, *Security Engineering*, Stack Exchange tags).
- Broad multilingual Wikipedia presence (languages listed include ar, ast, bn, ca, cs, de, el, en, es, fa).

## Body
### Definition and Scope
- **Cryptographic hash function**: a special class of hash function with properties that make it suitable for use in cryptography.
- Primary uses (as given):  
  - **cryptography**  
  - **hashing**

### Classification
- **Subclass of**:
  - **hash function**
  - **cryptographic primitive** (an established cryptographic algorithm used as a building block for more complex cryptosystems)
- **Opposite of**:
  - **non-cryptographic hash function**

### Related Concepts and Examples (from provided related items)
The source material lists multiple related cryptographic hash functions and families, including:
- **SHA hash functions** (family of cryptographic hash functions)
- **SHA-2** (set of cryptographic hash functions designed by the NSA; inception: 2002)
- Individual related hash functions (examples listed): **SHA-512**, **SHA-384**, **SHA-224**, **SHA3-224**, **SHA3-256**, **SHA3-384**, and **HAS-160**
- BLAKE family items appear in the provided material (e.g., **BLAKE**, **BLAKE2**, **BLAKE3**, and BLAKE2 variants)

### Constructions and Properties Mentioned
The provided material associates cryptographic hash functions with:
- **Merkle–Damgård construction** (method of building collision-resistant cryptographic hash functions)
- **HAIFA construction** (design method for cryptographic hash functions)
- **Puzzle friendliness** (listed as a property of cryptographic hash functions)
- **collision resistant hash** (a cryptographic hash function designed to resist collision)

### Identifiers and Knowledge Base Links
- **golden_id**: Cryptographic_hash_function-JPY88
- **Freebase ID**: /m/028pgb (publication date: 2013-10-28)
- **MathWorld ID**: CryptographicHashFunction (name qualifier: “Cryptographic Hash Function”)
- **Wikipedia title**: Cryptographic hash function
- **Commons category**: Cryptographic hash function
- **Topic’s main category**: Category:Cryptographic hash functions
- **Stack Exchange tags**:
  - https://crypto.stackexchange.com/tags/hash
  - https://stackoverflow.com/tags/cryptographic-hash-function

### Aliases (as provided)
- cryptographic hash
- CHF
- funcion hash criptografica
- calcul d'empreinte cryptographique
- kryptografische Hashfunktion
- kryptologische Hash-Funktion
- kryptographische Hashfunktion
- kryptografische Hash-Funktion
- ハッシュ関数
- 暗号ハッシュ関数

## Schema Markup
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  "name": "cryptographic hash function",
  "description": "A special class of hash function that has certain properties which make it suitable for use in cryptography.",
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## References

1. Freebase Data Dumps. 2013
2. [OpenAlex](https://docs.openalex.org/download-snapshot/snapshot-data-format)