It’s no secret that Bitcoin is secure. The network has operated with 99.99% uptime1 since its inception. Despite having a trillion-dollar target on its back, hackers have never broken into a single account.
Understanding why Bitcoin is so secure isn’t so simple. And understandably so. Bitcoin’s security model upends how we usually think about protection.
Typically, we think of security as gatekeeping. Banks defend your account by knowing who you are and expecting you to be able to prove it. On the other hand, Bitcoin doesn’t know your identity and doesn’t care to find out. A bank keeps your account balance confidential so as not to attract unwanted attention. As an open network, Bitcoin puts holdings on display for the world to see.
So just how does Bitcoin pull it off? When considering Bitcoin’s security, we’ll focus on three attributes: proof-of-work, decentralization, and the power of large numbers. Proof-of-work and decentralization protect Bitcoin at the network level. At the same time, large numbers are, crazy as it may seem, the solution to securing individual accounts.