A survey on blockchain for big data: Approaches, opportunities, and future directions[J] FUTURE GENERATION COMPUTER SYSTEMS-THE INTERNATIONAL JOURNAL OF ESCIENCE 2022(131) Deepa, N. Pham, Quoc-Viet Nguyen, Dinh C. Bhattacharya, Sweta Prabadevi, B. Fang, Fang Pathirana, Pubudu N. Gadekallu, Thippa Reddy Maddikunta, Praveen Kumar Reddy