Reading through some manuals, wikis and other documentation I'm learning about Merkle–Damgård construction. I understand why padding beginning with '1', followed by '0's is needed, but I can't understand why we're adding length of input in the end. This length-padding is called Merkle–Damgård strengthening. Could anyone explain to me why it's needed. I don't see the benefit.

  • $\begingroup$ Thanks. It didn't come out when I googled it, just found it here in the sidebar. It solves my question. You can close it. $\endgroup$ – Drag0 Dec 29 '15 at 13:49
  • $\begingroup$ cool, glad you were able to find the answer on here. $\endgroup$ – mikeazo Dec 29 '15 at 13:50