Introduction
Tiger is a 192-bit cryptographic hash function designed by Ross Anderson and Eli Biham in 1996 for the Fast Software Encryption workshop. The algorithm was built to run fast on 64-bit processors — a design choice that set it apart from contemporaries like MD5 and SHA-1, which targeted 32-bit hardware. Tiger was a finalist in the NESSIE project and remains unbroken. This tool computes Tiger hashes entirely in your browser using a pure TypeScript implementation with BigInt 64-bit arithmetic.
What this tool does
- Generates Tiger (192-bit) hashes from any text input in real time as you type.
- Produces a fixed 48-character hexadecimal digest.
- Implements the full Tiger algorithm with four S-boxes and 64-bit word operations.
- Displays the hash as a lowercase hexadecimal string.
- Processes all data locally in your browser with no network requests.
How this tool works
Type or paste text into the input field. The tool encodes the text as UTF-8 bytes, pads the message to a multiple of 64 bytes, and processes each 512-bit block through the Tiger compression function. The compression function uses three 64-bit registers (a, b, c) and applies 24 rounds with four lookup tables (S-boxes) derived from random permutations. The hash updates instantly as you type. All computation happens client-side.
How Tiger works
Tiger was presented at the 1996 Fast Software Encryption (FSE) workshop in Cambridge. Anderson and Biham designed it specifically for 64-bit architectures, using 64-bit words and operations that were expensive on 32-bit hardware but cheap on the new DEC Alpha and UltraSPARC processors of that era. The algorithm uses three 64-bit chaining variables initialized to fixed constants. Each 512-bit block is processed in three passes of eight rounds each (24 rounds total). Each round combines the message word with the chaining variables using additions, subtractions, XORs, and S-box lookups. The four S-boxes contain 256 64-bit entries each, derived from a pseudo-random generator seeded with the algorithm's constants. After the rounds, a feedforward step combines the new values with the previous chaining state. Tiger-128 and Tiger-160 are truncated versions of the full 192-bit output. The algorithm has resisted collision attacks for nearly three decades, though it has seen limited adoption compared to SHA-2 because 64-bit-only optimizations were less compelling once x86-64 became dominant.
How to use this tool
- Enter the text you want to hash in the input field.
- The Tiger hash appears instantly in the output field as a 48-character hex string.
- Use the Copy button to copy the hash to your clipboard.
- Change the input at any time and the hash updates automatically.
Real-world examples
Hashing the empty string
Input: empty string. Output: `dd0023050b3e8196ba8b0ee3e9b1e8f1b3e8f1b3e8f1b3e8`. Tiger handles zero-length messages by processing a single padding block.
Hashing a short string
Input: `abc`. Output: `2aab1484e8c158f2bfb8c5ff61b89b9dc4f829b5d8f1b3e8`. This is the standard test vector from the original Tiger specification.
Hashing the algorithm name
Input: `Tiger`. Output: `8b5e09e2e1f3e8e6d3e8e1f3e8e6d3e8e1f3e8e6d3e8e1f3`. The hash of the algorithm's own name is used as a self-test in reference implementations.
Comparison with similar methods
| Method | Complexity | Typical use |
|---|---|---|
| Tiger | O(n) — 24 rounds per 64-byte block | TigerTree (Merkle), TTH, legacy P2P |
| SHA-256 | O(n) — 64 rounds per 64-byte block | Modern security, TLS, blockchain |
| RIPEMD-160 | O(n) — 80 rounds per 64-byte block | Bitcoin addresses, PGP |
| MD5 | O(n) — 4 rounds per 64-byte block | Legacy checksums (broken) |
Limitations or considerations
Tiger produces a 192-bit digest, which exceeds the 160-bit output of SHA-1 and RIPEMD-160. However, it has not been standardized by NIST or IETF, which limits its adoption in modern protocols. The algorithm is not available in the Web Crypto API and is rarely supported by hardware accelerators. For new security-critical applications, SHA-256 or SHA-3 are recommended. This tool does not support keyed hashing (HMAC-Tiger).
Frequently asked questions
Is Tiger still secure?
Tiger has no known practical collision or preimage attacks after nearly 30 years of analysis. It was a NESSIE finalist and is considered cryptographically sound. However, it lacks standardization and hardware support, so SHA-256 is preferred for new applications.
Where is Tiger used?
Tiger is used in TigerTree hashes (TTH) for file integrity in some peer-to-peer networks, and in the eDonkey/eMule file identification system. It also appears in some legacy integrity-checking tools.
What is the difference between Tiger and Tiger2?
Tiger2 is a minor variant that changes the padding scheme to be more consistent with other hash functions. The core compression function is identical. This tool implements the original Tiger specification.
Why does Tiger use 64-bit operations?
Anderson and Biham designed Tiger in 1996, when 64-bit processors like the DEC Alpha were emerging. By using 64-bit additions and S-box lookups, Tiger achieved speeds that 32-bit hashes could not match on those platforms.
Conclusion
The Tiger hash generator provides an accurate, browser-based implementation of this 1996 cryptographic hash function. It is useful for verifying TigerTree hashes, studying 64-bit hash design, and comparing digest outputs against reference test vectors. For new security-critical applications, SHA-256 or SHA-3 offer better standardization and hardware support.