# Tiger

> cryptographic hash function

**Wikidata**: [Q1935697](https://www.wikidata.org/wiki/Q1935697)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Tiger_(hash_function))  
**Source**: https://4ort.xyz/entity/tiger

## Summary
Tiger is a cryptographic hash function designed by Eli Biham and Ross Anderson in 1995. It produces a 192-bit hash value and was optimized for 64-bit processors.

## Key Facts
- Created in 1995 by Eli Biham and Ross Anderson
- Produces a 192-bit (24-byte) hash value
- Optimized for 64-bit processors
- Also known as Tiger2, TTH, and TIGER - хэш-функция
- Official website: https://www.cs.technion.ac.il/~biham/Reports/Tiger/
- ITU/ISO/IEC object identifier: 1.3.6.1.4.1.11591.12.2
- Inventor: Eli Biham (Israeli cryptologist)

## FAQs
### Q: What is Tiger used for?
A: Tiger is a cryptographic hash function used to verify data integrity and create digital signatures. It generates a fixed-size 192-bit hash value from input data of any size.

### Q: How does Tiger differ from other hash functions?
A: Tiger was specifically optimized for 64-bit processors and produces a 192-bit hash value, which is different from the more common 128-bit (MD5) or 256-bit (SHA-256) outputs. It uses a different algorithm structure than SHA or MD families.

### Q: Is Tiger still considered secure?
A: While Tiger was designed to be secure against known attacks at the time of its creation, like all cryptographic hash functions, its security should be evaluated against current standards. It's less commonly used today than SHA-2 or SHA-3 families.

## Why It Matters
Tiger represents an important development in cryptographic hash functions, offering an alternative design optimized for 64-bit computing architectures when it was created in 1995. Its development by Eli Biham, a prominent cryptologist, contributed to the diversity of cryptographic tools available for data integrity verification and digital signatures. The function's optimization for 64-bit processors made it particularly relevant during the transition period when computing was moving from 32-bit to 64-bit architectures. While newer hash functions have since become more prevalent, Tiger's design principles and its role in expanding the cryptographic toolkit remain significant in the history of computer security.

## Notable For
- One of the few cryptographic hash functions optimized specifically for 64-bit processors
- Produces a 192-bit hash value, distinguishing it from more common 128-bit or 256-bit alternatives
- Developed by Eli Biham, a renowned cryptologist known for his work on differential cryptanalysis
- Has an official ITU/ISO/IEC object identifier, indicating formal standardization
- Available in multiple language Wikipedias, showing international recognition

## Body
### Technical Specifications
Tiger generates a 192-bit (24-byte) hash value, typically rendered as a 48-digit hexadecimal number. The algorithm processes data in 512-bit blocks and uses a 64-bit word size, making it particularly efficient on 64-bit processors. It employs a Merkle-Damgård construction with a distinct internal structure different from SHA or MD families.

### Design and Optimization
The hash function was specifically optimized for 64-bit processors, which was significant during the mid-1990s when computing architectures were transitioning. This optimization makes Tiger particularly efficient on modern 64-bit systems compared to some older hash functions designed for 32-bit architectures.

### Variants and Standards
Tiger2 is a variant of the original Tiger hash function that includes additional padding. The function has been assigned an official ITU/ISO/IEC object identifier (1.3.6.1.4.1.11591.12.2), which is used in formal standards and protocols. This standardization indicates its recognition within the cryptographic community.

### Creator Background
Eli Biham, one of the creators of Tiger, is an Israeli cryptologist known for his contributions to differential cryptanalysis, a method for breaking cryptographic algorithms. His involvement in Tiger's development reflects the function's foundation in advanced cryptographic principles.

## References

1. Freebase Data Dumps. 2013
2. [Tiger and Serpent ASN.1 OID's](https://www.cs.technion.ac.il/~biham/Reports/Tiger/oid.html)
3. [OpenAlex](https://docs.openalex.org/download-snapshot/snapshot-data-format)