Security Model

Bitcoin security is not one magic property. It comes from several layers working together: miners spend real resources, users wait for confirmations, attacks become economically painful, and holders take responsibility for their own keys.

This model is different from trusting an institution to reverse errors or make users whole. Bitcoin reduces trust in intermediaries, but it also asks users to understand the risks they now carry themselves.

The number of confirmations people wait for depends on context. A tiny retail payment may tolerate more risk than a large settlement between businesses. Time is part of the security model because it raises the cost of changing history.

Self-custody completes the picture. If you lose a seed phrase or sign a bad transaction, the network does not roll it back. Bitcoin can protect against arbitrary monetary changes, but it does not remove personal responsibility.