ABDUL GHAFFAR2025-09-262025-09-262019https://escholar.umt.edu.pk/handle/123456789/7113The main purpose of this research is to propose and implement a cryptocurrency (Bitcoin) wallet for the android operating system, by using the QR code-based application as a secure private key storage (Cold Wallet). Two android applications have been implemented; one of these is called Cold wallet and the other one is Hot wallet. Cold wallet is to store private key addresses for secure transaction confirmation and hot wallet is used to send bitcoin transaction to the network. Hot wallet application gives facility to the user to view history of performing transactions, to compose and send a new bitcoin transaction, receive bitcoin, sign it and send it to the network.enThesis