# RIPEMD-128

> cryptographic hash function

**Wikidata**: [Q3415207](https://www.wikidata.org/wiki/Q3415207)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/RIPEMD-128)  
**Source**: https://4ort.xyz/entity/ripemd-128

## Summary
RIPEMD-128 is a cryptographic hash function introduced in 1996. It is based on the earlier RIPEMD design and the MD4 hash function, and it is documented in RFC 2286 for HMAC-related test cases.

## Key Facts
- RIPEMD-128 is a **cryptographic hash function** (instance of the class “cryptographic hash function”).  
- RIPEMD-128 was introduced in **1996** (time of discovery/invention: 1996; inception: 1996).  
- RIPEMD-128 is **based on RIPEMD and MD4**.  
- RIPEMD-128 is associated with **Hans Dobbertin, Antoon Bosselaers, and Bart Preneel** (discoverer/inventor).  
- RIPEMD-128 is **described by**: **RFC 2286 — “Test Cases for HMAC-RIPEMD160 and HMAC-RIPEMD128.”**  
- The Wikipedia title for the entity is **“RIPEMD-128.”**  
- Known alias: **“Ripemd-128.”**  
- RIPEMD-128 is related to **RIPEMD**, which is also a cryptographic hash function.  

## FAQs
### Q: What is RIPEMD-128 used for?
A: RIPEMD-128 is a cryptographic hash function, meaning it is designed for cryptographic contexts where hashing is needed. It is specifically referenced in RFC 2286 in the context of test cases for HMAC constructions using RIPEMD-128.

### Q: Who created RIPEMD-128?
A: RIPEMD-128 is attributed to Hans Dobbertin, Antoon Bosselaers, and Bart Preneel. They are listed as the discoverers/inventors associated with the function.

### Q: When was RIPEMD-128 introduced?
A: RIPEMD-128 dates to 1996. Both its inception and time of discovery/invention are given as 1996.

### Q: What is RIPEMD-128 based on?
A: RIPEMD-128 is based on the RIPEMD hash function design and on MD4. These are explicitly listed as the foundations it builds upon.

## Why It Matters
RIPEMD-128 matters because it is part of the RIPEMD family of cryptographic hash functions and is explicitly tied to standardized testing guidance via RFC 2286. Cryptographic hash functions are a special class of hash functions intended for cryptographic use, and RIPEMD-128 is one such function. Its documented role in RFC 2286 connects it to practical verification and interoperability work around HMAC constructions, where test cases help ensure different implementations behave consistently. Historically, its 1996 introduction places it within an era of active development and refinement of hash function designs, and its stated basis in RIPEMD and MD4 situates it within a lineage of related cryptographic primitives. For practitioners and researchers, RIPEMD-128 is relevant as a named, inventor-attributed hash function with a clear relationship to both a broader family (RIPEMD) and a specific predecessor influence (MD4), and with an explicit appearance in an IETF RFC describing test cases.

## Notable For
- Being a **RIPEMD-family** cryptographic hash function **based on RIPEMD and MD4**.  
- Having a clearly stated **introduction year: 1996**.  
- Being associated with named inventors: **Hans Dobbertin, Antoon Bosselaers, and Bart Preneel**.  
- Being explicitly covered in an IETF document: **RFC 2286** (HMAC-RIPEMD160 and HMAC-RIPEMD128 test cases).  

## Body
### Classification
- RIPEMD-128 is a **cryptographic hash function**.
- “Cryptographic hash function” refers to a special class of hash function with properties suitable for cryptographic use.

### Origins and Timeline
- **Inception / invention time:** **1996**.
- **Discoverers/inventors:** **Hans Dobbertin**, **Antoon Bosselaers**, **Bart Preneel**.

### Design Lineage
- **Based on:**  
  - **RIPEMD** (a cryptographic hash function)  
  - **MD4** (listed as a basis for RIPEMD-128)

### Standards and Documentation
- **Described by source:** **RFC 2286**, titled *“Test Cases for HMAC-RIPEMD160 and HMAC-RIPEMD128.”*
- This RFC provides test-case context specifically referencing **HMAC-RIPEMD128**.

### Names and Identifiers
- **Primary name:** RIPEMD-128  
- **Alias:** Ripemd-128  
- **Google Knowledge Graph ID:** /g/120t4961

### Related Entities
- **RIPEMD** is listed as a related entity and is itself a cryptographic hash function.