5/5
Until mid-2023, Bitcoin ran below 400 EH/s. Fourteen years, never 51% attacked.
What protects Bitcoin isn't the absolute number on the hashrate chart. It's the cost asymmetry between attackers and the value at risk. And that asymmetry remains enormous.
4/5
The real defense is economic and operational. An attacker would need to acquire and power hundreds of EH/s, coordinate it undetected, and monetize the attack before exchanges, custodians, and pools respond.
The market would reprice the attack immediately.
Succeeding is the
3/5
Power draw at ~13.5 W/TH lands at around 13.5 GW. Roughly Belgium's electricity demand.
Energy at $0.06/kWh runs about $810,000 per hour.
Halve the network and halve all of it. A 500 EH/s baseline still implies several billion in capex and 5 to 7 GW of power.
2/5
The textbook attack: controlling more than 50% of network hashrate to reorganize past blocks. Let's price it.
At today's ~1,000 EH/s network, an attacker needs roughly 1,000 EH/s of fresh hashrate. At $8 to $25 per TH, that's $8B to $25B in hardware alone.
1/5
Two things that are almost always confused.
Private-key security has nothing to do with hashrate. Elliptic curves and SHA-256 don't care how many machines are mining. Your keys are as safe at 400 EH/s as at 1,200 EH/s.
What hashrate secures is consensus.
The natural question follows: if hashrate halves, does that put the network at risk?
The honest answer is no. And it's worth walking through carefully, because this is where the public conversation gets sloppy.
We are experiencing the first bear market in network hashrate in Bitcoin's history.
This is the longest stretch without a new network hashrate ATH in the ASIC era.
~258 days since the last ATH and still ~25% below the peak.
I wrote about this last month:
5/5
This is almost certainly the first real bear market in Bitcoin's network hashrate.
For fifteen years it has only moved in one direction. Many who decided to leave mining modeled it as if it always would.
Full letter from our CEO Rapha Zagury:
3/5
In 2021, machines went offline because they had to. China "unplugged" them.
As soon as they found a new home, hashprice supported the math and they came back on. They were homeless, not unprofitable.
2/5
The trend is not flat or consolidating. It is quietly grinding lower.
This isn't a mirror image of 2021. The shape is different.
Slowly down the escalator.