MD5 is 1=>1?

On Mon, 4 Jul 1994 nobody@shell.portal.com wrote:

Now if I have entered a phrase with EXACTLY 128 bits of entropy, hypothetically, is that enough to have flushed the padding or whatever out of the pipeline? I have had this question also, has it been shown that the transformation of 128bit words through md5 is *theoretically* invertable, as if it is not, iterating it 1024 times could actually make you *LOOSE* entropy. (say it was a random transformation, it would not contain each of the 128 bit outputs, ie some inputs would map to the same output.)

I am not aware of any such result. Roger.