MARCH 22
Why Bitcoin Survived
The Difference Between Being Attacked and Being Broken
The Signal
Bitcoin survives because independent computers reject anything that breaks the rules.
The Reading
Yesterday, Bitcoin faced its first major exploit. A flaw in the early software created more than 184 billion bitcoin inside one block, although only 21 million should ever exist.
The failure was enormous, but visible. Jeff Garzik spotted it. Developers found the flaw. Satoshi released a repair. Users adopted it. Miners built the valid chain and left the broken version behind.
Bitcoin had been attacked. It had not been broken.
A full node checks Bitcoin for itself. It trusts nobody. It verifies signatures, checks that coins exist, rejects double spending and ensures new coins follow the rules. Break one rule and the block is rejected. Computing power cannot make a false transaction true.
The blocks are joined together. Each contains a fingerprint of the block before it. Change an old block and every link after it breaks. The attacker must rebuild that work and catch a valid chain that never stops growing.
Bitcoin is not an exchange or wallet. An exchange can be hacked. A wallet can fail. Seed words can be stolen. People can be tricked. These losses are real, but they do not mean Bitcoin’s chain was broken. A bank robbery does not mean money itself was hacked.
Trust Bitcoin for the right reason. Not because attacks never happen, but because nobody can order the network to accept a lie. Independent computers check the rules. Proof of work protects the valid history.
First Principles
Full nodes independently check every block.
Computing power cannot make an invalid transaction valid.
A hacked exchange, wallet or private key is not a broken Bitcoin chain.
Today’s Challenge
Find six books and stack them. Each book represents a Bitcoin block. The bottom book is the oldest.
Now replace the second book from the bottom. You must remove every book above it, make the change and rebuild the tower. Ask someone to keep adding books while you try.
That is the attacker’s problem. The chain keeps growing. Every replacement must also obey Bitcoin’s rules or independent computers reject it.
The attacker must pass every check, rebuild the work and catch a tower that never stops growing.
Attacking Bitcoin is possible. Breaking it is something else entirely.
Tomorrow’s Signal
No CEO, No Headquarters