If you’ve been living under a rock, or on Pluto (and if that’s the case — how can we join you?) Bitcoin’s hash rate is increasing exponenentially.
In mid-October, Bitcoin reached a milestone by surpassing a hash rate of over 100 quintillion hashes per second. That's a 1 with 20 zeros! If you laid out 100 quintillion coins flat like a rug, they would cover the surface of the earth over two hundred times.
A 51% attack would allow criminals to block transactions and then allow them to double-spend their own Bitcoin. However, Satoshi designed the Bitcoin network to be more profitable to help secure the network rather than to attack it and the hash rate is a core part of this.
For 51% attack to be successful, a group of miners would have to control more than 50% of the network’s Bitcoin mining hash rate. It follows that the higher the hash rate, the more difficult it becomes to execute such an attack.
In addition he higher the hash rate becomes, the higher the mining difficulty, something else built into the system by Satoshi. This is because there is more competition. Finding a hash depends on how lucky you are. Higher hash rate equals more competition, and more required luck.
To increase the chances of solving a hash, Bitcoin Miners are purchasing more advanced/expensive computers,. mainly ASIC equipment simply because it’s the fastest way to solve a SHA256 equation. The good ones cost upwards of $3000. According to a site that tracks how much it would cost to execute a 51% attack, it would set you back $1.4 billion.
Not worth it, is it?