Researchers and practitioners are paying increasing attention to blockchain's potential for resolving trust, privacy, and transparency-related issues in smart education. Research on educational blockchain is also becoming an active field of research. Based on 206 studies published from 2017 to 2020, we identify contributors, collaborators, applications, and research topics using topic modeling and bibliometrics. Results indicate that currently, studies on the educational blockchain are mostly published in computer science conferences, with few in educational technology journals. Asian countries/regions (e.g., China and India) and institutions (e.g., University of Raharja) are active in this field. Countries/regions and institutions from the same regions tend to have close collaborations. Blockchain is mainly used to facilitate online testing and learning, education data mining and analytics, resource sharing, educational record verification and authentication, data management and storing, administration management, education/discipline of children, and college crowdfunding. Based on the results, we highlight the need to integrate artificial intelligence to enhance scalability and security and to facilitate justification and personalization of blockchain solutions based on accumulated big data to capture abnormal behaviors. This study assists researchers and practitioners in understanding educational blockchain research and becoming aware of the hot topics and future directions.