Can Bitcoin be hacked?

The Bitcoin network is extremely difficult to hack. This is mainly because of the technology that underpins it – the blockchain. 

The blockchain records and indexes Bitcoin transactions, creating a searchable database of all of them in the process. Think of it like a normal ledger. However, unlike traditional ledgers, the Bitcoin blockchain is decentralised. This means that, rather than store information on a central server, a blockchain stores transactional data across a vast network of computers that is continuously checking and verifying that the records are accurate. 

This makes hacking them a lot harder. Instead of having to breach only one central server, a hacker would have to compromise 51% or more of the network to compromise information. Imagine walking into a room and finding a single vault. It might have a lot of security, but once you get through that, you’re in – you can access whatever it contains. Now imagine you have a hundred rooms, with a hundred different vaults in them. All of them have a piece of a map inside that tells you how to get to the single vault, and you can’t figure out what the map tells you without having more than 51% of it. Harder, right? 

However, although it is extremely difficult to hack, in theory, it is not impossible. A 51% attack is where an attacker gains control over a majority of the Bitcoin network’s hashrate, or computing power. This would enable the attacker to mine blocks faster than the rest of the entire network combined.

Such an attack is unlikely to happen though, as it’s very expensive to perform and, as a result, mainly low-hash power coins are susceptible to this kind of attack. Bitcoin’s hashrate is currently at an all-time high, recently surpassing 100 quintillion hashes per second. This means that anyone who wants to use this attack method would need an extremely high amount of computing power to successfully dominate the majority hashrate, which would cost a huge amount. Since its release in 2009, the Bitcoin network has yet to be hacked.