We start with a compression function with parameters such that and .

The reason for is that we want to be a compression function, so the input must be larger than the output.

So we only need to show that the compression function is secure.

The matrix used in the compression function may grow large in certain situations.

One-way compression function - Hash functions can be made from block ciphers.

One-way compression functions are often built from block ciphers.

Thus, to turn a block cipher into a one-way compression function some extra operations have to be added.

See one-way compression function for descriptions of several such methods.

The function in step 4 is called the compression function.

The quasigroups used in every iteration of the compression function are different and depend on the processed message block.