Given h = sha256(k ∥ m), where k is a secret and "∥" means concatenation (no padding is involved in calculating h). describe a message x such that one can calculate sha256(k ∥ x) without knowing k. note that your described x should not the same as m, but could be a concatenated message

What is the biggest difference between section breaks and regular page breaks? section breaks are more difficult to add than page breaks. section breaks make it easier for you to view the document as an outline. section breaks allow you to have areas of the document with different formatting. section breaks are smaller than regular page breaks.