## 6 Key Findings
### Open Challenges and Future Work
#### 6.2.2 Smart Contract Enhancements  
Regardless of their nature, databases do not have an inherent verification mechanism. The proposed smart contract solves this by tracking the off-chain information with hashes, allowing it to detect fraudulent changes, acting as a watchdog. However, the flexibility of Solidity smart contracts allows for the consideration of several academic processes. For example, the modifications to the AR could be performed on-chain, that is, directly in the smart contract. An example of such enhancement would be to create a smart contract per subject. Such'subject' smart contracts would share the same structure, so a Manager or Factory pattern could be used [115]. This way, subjects would be identified by their contract address, and they would be effectively identified by their parent smart contract (e.g., a smart contract that represents a specific degree). Additionally, the complexity of the education regulations should be considered. For example, the Bologna Process rules may change annually. Such changes would require the smart contracts to be 'upgradable', a feature that would make the contract sustainable for the long-term [116]. The aforementioned smart contracts could handle different kinds of processes that affect the AR, ranging from academic results to reputation systems based on different kinds of actions. For example, the subject smart contracts would typically contain a method to link students to achieved marks, not only for final exams but also for the completion of other tasks. Such results would not be stored for every student, as this would create a massive on-chain structure that would increase the gas fees to an unfeasible extent. Rather, event tracking can be used. Such methods would trigger events whenever they are called, so verifying the results of students would simply require read operations to the blockchain history, avoiding expensive data structures such as mappings or arrays and providing a 'green' and scalable solution to the academic field. Other examples of such functions may include a method to add new members to the validation committee (e.g., new professors, program directors). This is aligned with the concept of DAO smart contracts, where different kind of organizational decisions could be taken in a transparent manner. The scope of these DAOs could range from the subject departments to a multi-party, cross-border consortium of institutions. With the proposed new system, professors would be able to independently trigger transactions involving students' results. Therefore, these transactions would publicly register data such as the author of such assessment (i.e., the message sender), the moment of such assessment (block timestamp), the affected student and the final score, among other possible data. This evidence in the form of blockchain transactions would make the process completely auditable, potentially preventing fraud. Also, such transparency in the process would avoid the current validation process, where a set of administrators needs to supervise every off-chain change. In fact, avoiding such a validation process would be aligned with reality, where professors are assigned different subset of exams and they do not respond to corrections performed by others. In addition, the proposed smart contract enhancement would address cases of public/private key pair loss. Such a matter is an important concern within decentralized systems, as it determines the resilience of the overall system to attacks such as key hijacking. In the current system, such loss would impede the student to access his/her AR, while administrators would not be able to access his/her validation panel. To tackle this issue, a possible solution would involve notifying the loss to the administrative department of the university, along with some physical verification evidence. The public key field of the AR would require to be changed off-chain and then be confirmed by the administrative department of the university.