From AMule Project FAQ
NOTE : the hash used in ed2k protocol URLs in NOT MD4 !!! It is similar but not the same. Above certain filesize (the exact value is documented somewhere) the MD4 and the ed2k hash for the same data are not the same. Anybody can check this by computing a hash of any file greater than 15 megabytes using any hash tool, like HashCalc, fsum etc.
see also my comment on the MD4_hash page.
--Xerces8 11:52, 5 Jan 2007 (CET)