This standard specifies dedicated hash functions, ie specially designed hash functions. The hash functions of this standard are based on the iterative use of round functions. This standard specifies three different round functions, resulting in different dedicated hash functions. The first and third types provide hash codes up to 160 bits in length, and the second type provides hash codes up to 128 bits in length.
GB/T 18238.3-2002 history
2002GB/T 18238.3-2002 Information technology--Security techniques--Hash-functions Part 3:Dedicated hash-functions