Providing user authentication services using blockchain-based software technology for cryptocurrency transactions; Customizing, maintaining, and updating of computer software used by others to develop blockchain-based software applications; Providing online, non-downloadable software for blockchain transaction analytics, cryptocurrency wallet screening, digital asset transaction monitoring, risk scoring of blockchain addresses and cryptocurrency transactions, investigative graph analytics, entity attribution workflows, cross-chain tracing, alerts, case management, sanctions exposure detection, anti-money laundering workflows, fraud detection support, and financial crime investigation workflows using blockchain technology; Hosting of blockchain databases; User authentication services using blockchain technology for cryptocurrency transactions; Application service provider featuring application programming interface (API) software for blockchain transaction monitoring, cryptocurrency wallet screening, digital asset transaction screening, and risk scoring of blockchain addresses and cryptocurrency transactions; Application service provider featuring application programming interface (API) software for analyzing financial assets and transactions to identify risk scores for blockchain addresses and transactions; Providing temporary use of on-line non-downloadable software for accessing, reading, and tracking information in the field of financial transactions on a blockchain