The antonyms for the word "fraudulent data" could be "authentic data," "genuine data," "accurate data," "bonafide data," or "valid data." These antonyms represent data that is true, reliable, and legitimate. Authentic data refers to information that is reliable, trustworthy, and verified. Genuine data is data that is real, not fake or counterfeit. Accurate data is information that is precise and factual. Bonafide data is data that is genuine, real, and in accordance with the law. Valid data is information that is acceptable, correct, and consistent with reality. Using authentic, genuine, or accurate data helps to build credibility, trust, and transparency in decision-making processes.