Although these early digital currencies took shape, they were centralized, and therefore vulnerable to attacks by governments and hackers. Early digital currencies used a central clearinghouse to handle all scheduled transactions, much like a traditional banking system. Unfortunately, in most cases, these emerging digital currencies have become the target of government concerns and eventually disappeared from the legal process. Others failed when the parent company that issued them suddenly defaulted. To stand firm against interference from rivals, whether legitimate governments or criminals, a decentralized digital currency needs to avoid single-node attacks. Bitcoin is exactly that kind of system, completely decentralized by design and not controlled by any central authority or central point, a monetary system that is immune to attack and corruption. 

 mình không thể tưởng tượng cuộc sống của mình nếu thiếu đi sự hiện diện của chị. 👋 Thương quá!