# Blockchain Applications in Education: A Systematic Literature Review
## 4 Discussion
### Research Question 3: What Are the Unresolved Issues of Blockchain in Education? Although blockchain has many relevant features that can benefit the educational field, as discussed in the previous sections, there are still several drawbacks and challenges that need to be addressed and questions to be responded to under the prism of the reviewed articles. Some problems correspond to generic limitations of blockchain technologies that affect the educational sector, while others are specific to their application in education. Both types are summarized in the next paragraphs. Blockchain, as discussed in most articles, is a still immature but rapidly evolving set of technologies, and its adoption in the educational field is still in an early stage of development [18]. There is a need for more research to better understand, characterize, evaluate its usefulness and tackle open issues, for example to create academic certificates [19]. As a relative new set of constantly-evolving technologies, in many cases a complete application programmers' interface (API) is not available to integrate new proposals or legacy systems [13], and at this time there are concerns about the sustainability of the chosen blockchain platforms [42], since there are hundreds of them with different business models and commitment from their developers. Blockchain and its properties and benefits are, indeed, not easy to understand for the general public [25] and therefore there is a lack of trust in the platform [15]. This is also because blockchain is highly hyped and not always the best solution to all projects, where other technologies are more appropriate [13]. Nevertheless, as described in Section 4.1, there are many initiatives, some of them prototyped and even used in real scenarios as a proof of concept. It would be very helpful if the expertise and results of these pilots were shared among institutions [39; 46] and if there were more collaboration among all actors involved to foster the general adoption of blockchain technologies. Education has a global dimension and involves many stakeholders who must consider the existence of others, although they could be organizationally independent. Blockchain brings to this field many applications that require a new open interconnection model [36] that is not always easy to integrate in the academic organizations and their proprietary systems, and that can play against their own interests or strategies. Security is a key blockchain feature. However, there are still security framework issues [41] regardless of the hard work of the community to make it stable and safe. Platforms like Bitcoin and Ethereum are the target of constant external attacks [42] that try to exploit current and future vulnerabilities. Storing educational information in blockchain is a risk due to the possibility of bugs in the application or in the platform, or even because the participants do not protect properly their private keys [31]. Privacy in blockchain is not easy to achieve and consequently is a problem in some use cases in the academic field that handle sensitive information. Public blockchains are not a proper solution to store this data, even when encrypted [26], and therefore private or consortium blockchains are preferred [37]. Notwithstanding, some regulations in different countries protect personal information. As an important limitation in Europe, the European General Data Protection Regulation (GDPR - General Data Protection Regulation is regulation EU 2016/679 of the European parliament and of the council on the protection of natural persons with regard to the processing of personal data and on the free movement of such data, and repealing Directive 95/46/EC.) does not allow for any personal information to be registered in an undeletable storage, such as a blockchain [13], and data must be anonymized. This topic is widely discussed and must be solved before applying blockchain in the educational field to register people's data.