The original sentence was for one act of disobedience, the atonement covers a multitude of transgressions. The next three verses are the heart of Paul's analysis of sin atonement. However the fine logic is diluted by the various English translations of these verses. Of the three words dikaiosune is easiest to identify. The distinction between dikaioma and dikaiosis is not as easy to determine.
Lexicographers disagree amongst themselves.
Writing in 1858, J.A. Bengel in his Gnomon of the Greek New Testament , says just the opposite. Both agree that the two are related as cause to effect. They just disagree on which is cause and which is effect. The contrast is drawn between the original sin which was one act and the free gift of the ransom which covered a multitude of transgressions. This, however, is only the beginning of the atonement work.