Coin Recovery from Inaccessible Cryptocurrency Wallet Using Unspent Transaction Output

In 2008, the blockchain technology was invented to create a modern electronic cash transaction protected through cryptographic mechanisms in peer to peer or decentralized network. The first success cryptocurrency based on blockchain technology is Bitcoin, which core processes are based on public key cryptography. While the public key is transformed and used as an address for payment, the private key is used to claim ownership to access the funds stored in the correspondent address. The processes of generating addresses, signing transactions, and checking the balance are parts of the cryptocurrency core processes. With these activities, the wallet application was created to assist and handle the execution of those processes.The private key plays the most important component to interact with assets inside cryptocurrency blockchain database. Without the private key, the asset in blockchain will not be managed or controlled, thus all cryptocurrency coins in correspondent wallet will be lost. This paper provides a solution to recovery cryptocurrency coin that lost according to inability to login to wallet application. The main component used to recover coins in this paper is the unspent transaction output.