The PHP's version of Tiger 160-bit algorithm (3 passes) - truncated version, also known as Tiger/160 can be used for compatibility with protocols assuming a particular hash size.

Tiger is a cryptographic hash function designed by Ross Anderson and Eli Biham in 1995 for efficiency on 64-bit platforms.

Unlike MD5 or SHA-0/1, there are no known effective attacks on the full 24-round Tiger except for pseudo-near collision. While MD5 processes its state with 64 simple 32-bit operations per 512-bit block and SHA-1 with 80, Tiger updates its state with a total of 144 such operations per 512-bit block, additionally strengthened by large S-box look-ups.