MD5: The broken algorithm - Avira Blog Jul 28, 2015 · The leading bit in the first nibble is flipped to make 01100010, which is 0x62 as shown in the lower sample (File B). All that is needed to generate two colliding files is a template file with a 128-byte block of data, aligned on a 64-byte boundary that can be changed freely by the collision-finding algorithm.