## 5 Evaluation and Discussion
### The Real Impact of UniChain in Managing EARs
On the other hand, the proposed UniChain system will be built above the existing academic provider databases to facilitate the integration with the existing systems. To reduce the requirements of storing EARs in the blockchain and to utilize the existing systems, EARs will be continuously stored in the provider databases. As universities currently maintain and manage the EARs, while students can only read data, provider nodes in the proposed design will be responsible for the maintenance of the blockchain. According to an article that was published in the Applied Sciences Journal in June 2019 [30], a blockchain could bring several benefits to education: (1) improving security that includes data protection, privacy, and integrity; (2) providing better control on how students' data are accessed and by whom; (3) enhancing accountability and transparency; (4) enhancing trust between all included parties and ease the communication between them; (5) lowering the cost as the nature of blockchain technology can help in reducing the unnecessary cost associated with the transactions and storage of data; (6) authenticating students' identities as well as their digital certificates; (7) the efficiency of data exchange and the management of students records; (8) enhancing interoperability; and (10) supporting future career. The UniChain system employs the blockchain technology, which is a collection of techniques (cryptography and hash functions) to create a chain of data where each new piece of data is linked to the previous ones by a cryptographic hash function. Therefore, it significantly increases the difficulty of attack and improves the privacy and security of EARs. All accesses to the EARs will be performed through the blockchain, and accordingly the history of those accesses will be stored in the blockchain to provide a full view of all events occurred to EARs. Thus, it ensures the integrity of data and prevents misuse of a student EAR. All logs details in addition to the record ownership metadata will be added to the chain. Sensitive information that are placed on the blockchain are encrypted to decrease the possibility of being accessed by unauthorized entity. UniChain system increases the level of data obfuscation by separating sensitive information via the use of SRHC, RC and ACC. The use of deposit-box technique is employed to solve the problem of transferring encrypted messages among nodes with no need to share symmetric key. The proposed framework employs the hashing methods, i.e., SHA-256, to ensure data integrity. UniChain keeps a hash value of the link that will be created during the record's issue to access the EAR in the blockchain instead of keeping the link itself. To access a record, the encrypted query link will be sent over HTTPS to the associated participant who has access rights. Therefore, its hash value stored in the blockchain ensures that no alterations have been made outside the blockchain during the transfer as the value of the hash is unique to the original document. For further security, UniChain will store the query link, the key and the EARs in different locations. Privacy is maintained in the UniChain by employing timed-based smart contracts for governing transactions. Security and access control are maintained by the adoption of advanced encryption and authentication techniques throughout the blockchain. Interoperability, auditability, and accessibility are provided by the use of smart contracts and comprehensive logs. For creating, validation, and appending new block, the proposed system employs a new incentive mechanism integrated with the Proof of Authority (PoA) consensus algorithm. The proposal leverages the degree of providers nodes from the perspective of EARs systems by measuring their efforts regarding maintaining academic records and creating new blocks. Provider nodes with fewer degrees are more likely to be selected for creating the new block.