Secure Smart Contract Based on Blockchain to Prevent the Non-Repudiation Phenomenon

Blockchain is an innovative technology that has gained interest in all sectors the era of digital transformation where it manages transactions and saves them a database. With increasing financial rapidly developed society with growing businesses many people looking for dream better financially independent life, stray from large corporations organizations to form startups small businesses. Recently, demand employees or institutes prepare manage contracts, papers, verifications process, addition human mistakes led emergence smart contract. The contract been save time provide more confidence while dealing, as well cover security aspects management solve negotiation concerns. was employed creating distributed ledger eliminate need centralization. In this paper, simple prototype implemented integrated blockchain which simulated local server set nodes. Several objectives, such confidentiality, authorization, integrity, non-repudiation, have achieved proposed system. Besides, paper discussed importance using technique, how contributed highly transparent real-estate scenarios. elliptic-curve public key adopted alternative RSA signature generation/verification process encryption protocol. For secure transactions, Secure Socket Layer (SSL) also layer web browser. results investigated evaluated different implementation restricted environment. Experiments showed us complexity cost when (ECC) algorithm (RSA) depending on size length key. So if equals (160) bits, corresponds (1024) bits (RSA), equivalent 40% 30% (RSA). As result, complex, its smaller generating faster, so high level security.