# Blockchain-Based Badge Award with Existence Proof
## 1 Introduction  
Blockchain technology is used as the base technology in many fields because it uses a distributed, decentralized database without any central control over the system and is highly secure owing to the use of the SHA 256 algorithm [1]. A survey conducted by the World Economic Forum in 2015 found that those polled believe that there will be a tipping point for government use of blockchain by 2023 [2]. Governments, large banks, software vendors, and companies involved in stock exchanges, especially the Nasdaq stock exchange, are investing heavily in this area. For example, the UK Government recently announced that it is investing \(\EUR{10}\) million for blockchain research [3] and Santander has identified 20-25 internal use cases for technology that can predict a reduction in banks' infrastructure costs by up to \(\EUR{12.8}\) billion a year [4]. To understand the relevance of blockchain in the education system, it is important to understand its components and implementation on educational networks. Blockchain is a distributed record of digital events that are linked together to maintain the link and hash values of previous events [5]. In this way, all the events are liked with the chain and stored on each computer in the same network. Everyone can see the events, but no one can change the information,not even the owner of the event. Public blockchains are accessible to everyone and have the potential to add new blocks to the chain, whereas private blockchains are used by organizations. The best known blockchain is the one at the heart of the Bitcoin system of digital money [6]. \"Proof of work\" is an important feature of the blockchain technology, where a new block is checked for legitimacy and is added to the chain of blocks. This is done using special notes for the benefit of incentives. This is a verification process, which is also called as mining, and in an education system, the badges are verified using the mining method. It is nearly impossible for any hacker to hack a blockchain, and this makes the Bitcoin blockchain a highly trusted platform [7; 8]. Mining requires considerable amount of power and electricity, and even if a hacker has all these things, he/she will still need to spend a considerable amount of time on the network. A blockchain is formed by linking many blocks together, and each block can hold nearly 1 Mb of data in it. In the Bitcoin network, the blocks contain the timestamp, transactions, and hash of the previous block; however, in our educational network, the blocks contain course credit, assignment, skills, etc. Every student and teacher can see the skills of the student, but they cannot make any changes. The students are able to show their skills by referencing backpack websites containing all the acquired badges. The badges are compatible with most of the internet platforms and can be shared over the internet or social media. IMS Global provides the certification of badges and OpenBadges provides the configuration of the badges. In this research, the issuance of badges and verification is done using the Badgr [9] platform. Originally, a badge in the Badgr platform is only a trust relationship between two parties. This means that so far we have not been able to create chains of trust and networks of trust. However, in this study, we extended and implemented the trust relationship among all participants in the distributed environment of blockchain with regard to the following concerns. (1) Elimination of the inefficiency and social cost problems of various certificate issuing systems: There are some inefficiencies and inconveniences in the certificate issuing systems of educational and public institutions, provided through the existing information system. There are costs related to the issuance of certificates, transcripts, and diplomas for online and offline education and training courses.