Bitcoin Security: A Complete Analysis of Every Attack Vector

Bitcoin’s security model is one of the most sophisticated ever designed. Understanding every attack vector — from 51% attacks to dust attacks to social engineering — is essential for anyone serious about Bitcoin custody and network security.

The Consensus Layer: Can the Network Be Shut Down?

51% Attacks

A 51% attack is when a single entity controls more than 50% of Bitcoin’s hash rate. They can then:

• Censor transactions: refuse to include certain transactions in blocks
• Reverse transactions: mine a secret chain and broadcast it when it overtakes the public chain (double-spend)
• Reduce network efficiency: orphan blocks from honest miners

What a 51% attacker cannot do:

• Steal BTC from addresses they don’t control
• Change Bitcoin’s consensus rules
• Create BTC out of thin air (except through block reward)

The economics: at 700 EH/s network hash rate, a 51% attack requires approximately 357 EH/s of hash rate. At current ASIC prices ($30-50/TH) and electricity ($0.05/kWh), renting this ha