Platform as a service (PAAS) featuring computer software platforms for privacy-preserving machine learning model training using federated learning; Providing a website featuring non-downloadable software using artificial intelligence (AI) for privacy-preserving machine learning model training and validation; Providing temporary use of on-line non-downloadable cloud computing software using artificial intelligence (AI) for privacy-preserving machine learning model training using federated learning; Providing online, non-downloadable software for blockchain-verified reward distribution to data contributors using blockchain technology