Crossword puzzle clue "a good one is cracked"

A good one is cracked

Shakespeare character who says "Good night, ladies; good night, sweet ladies; good night, good night"

Good ones are cracked

Good ones are never cracked

One might be cracked

One might be cracked

French mathematician Henri whose conjecture was one of the great unsolved problems (until it was cracked in 2003)

One may be cracked