About TIGER128,4 hash
Tiger128,4 is a cryptographic hash function from the Tiger hash family, designed to produce a fixed-length hash value of 128 bits (16 bytes). The "4" in the name refers to the number of rounds used in the compression function of the Tiger hash.
Characteristics of Tiger128,4
Fixed-Length Output:
- Tiger128,4 produces a fixed-length output of 128 bits (16 bytes).
Input Padding:
- Tiger128,4 pads the input message so that its length is congruent to 512 bits (64 bytes) modulo 256. It appends a single '1' bit followed by '0' bits until the message length is 256 bits less than a multiple of 512. The length of the original message is then appended in bits.
Processing in Blocks:
- Tiger128,4 processes the input message in 512-bit (64-byte) blocks.
Initialization Vector (IV):
- Tiger128,4 uses an initial vector (IV) that is initialized during the setup of the compression function.
Compression Function:
- The compression function of Tiger128,4 operates on a 512-bit state and uses a combination of substitution-permutation network (SPN) and a Feistel-like structure. It involves four rounds of mixing, substitution, and permutation operations.
Algorithm Steps
Initialization:
- Initialize the 512-bit state and set the initial vector (IV).
Padding:
- Pad the input message according to the specified padding rules.
Processing:
- Divide the padded message into 512-bit blocks.
- For each block, apply the four rounds of the compression function, updating the state.
Output:
- After processing all blocks, extract the final 128-bit hash value from the state to produce the hash value.
Security and Usage
Security:
- Tiger128,4 is designed to provide moderate security against collision attacks and preimage attacks. Its 128-bit output size offers basic security properties suitable for applications where moderate security assurances are sufficient.
Usage:
- Tiger128,4 has been used in various applications requiring a 128-bit hash function, such as checksums and data integrity verification. However, its adoption has been somewhat limited compared to more widely accepted hash functions like SHA-2 and SHA-3, which offer stronger security assurances and are more standardized in modern cryptographic protocols.
Summary
Tiger128,4 is a cryptographic hash function that produces a 128-bit hash value. It provides moderate security properties against certain types of attacks and has been used in specific applications where a 128-bit hash function is sufficient. However, its usage has been overshadowed by more widely recognized hash functions with stronger security guarantees in contemporary cryptographic applications.