A Blockchain Smart ContractApplication Framework

Blockchain is an emerging technology which gained popularity with Bitcoin, which is the most famous application of that technology. After Bitcoin became popular, new usage areas of Blockchain was started to being investigating because of the advantage of the technology such as security, agentless transaction, and transparency. HAVELSAN is a large scale software company, investigates on new generation technologies and works on to adapt it. In this manner, Blockchain is one of these new generation technologies that brings impressive advantages. Blockchain is a decentralized transactional database technology in which all transactions are encrypted on blocks, allowing the buyer and seller to make a secure exchange between themselves directly. In this transactional database technology, all transactions are recorded in a structure called “Distributed (Open) Ledger”, where transactions are held and open to all users. In the traditional approach (central database), when the database is controlled by a third party, the copy of the database in the Blockchain approach is available to all participants. This prevents the data from being corrupted and destroyed. In order to be able to modify this distributed structure, the relevant changes must be recorded on all computers in the system. The success of any type of cyber attack becomes impossible because of the necessity of accepting changes in the vast majority of the network. Smart Contract is a key concept of Blockchain in order to gather all these advantages. Smart Contracts not only define the rules and penalties around an agreement in the same way that a traditional contract does, but also automatically enforce those obligations. HAVELSAN is a large scale software company that has wide range of operation field, so there could be different applications of Blockchain with regard to company operation fields. Combining this variety with the importance of Smart Contract concept, which could be counted as the basis for most Blockchain applications, it is beneficial to establish a strong based Smart Contract frame before starting to build our own applications with Blockchain. Therefore, we aimed to build our customized Smart Contract structure before developing miscellaneous applications. In this article, HAVELSAN Blockchain Smart Contract framework establishment; which infrastructures were used, the problems encountered during the development and the most applicable way of use this framework will be explained.