Bitcoin: who orders transactions?

Who controls it

Transaction ordering

Permissionless proof-of-work miners choose and order the valid transactions in each block; full nodes independently enforce the consensus rules.

Escape hatch

None needed: Bitcoin is a native settlement layer with no bridge or sequencer.

Upgrade authority

No administrator or upgrade key. Rule changes depend on software adoption by miners, economic actors, and independently operated full nodes.

Halts and outages

Mainnet block production is continuous, and finality is probabilistic. Accumulated proof of work resolves temporary forks. No operator can halt the chain, so the safety events to observe are deep reorgs and sustained control of a majority of hashpower.

Ketju assessment

Ketju approves Bitcoin as a settlement layer: block production is permissionless, nodes enforce the rules independently, and no key can rewrite balances or force a protocol upgrade. Bitcoin has the cleanest control model in this group of chains, and no bridge sits beneath the native asset. Mining pools still coordinate operations, and probabilistic finality calls for a confirmation policy. Neither gives any party the unilateral control that Ketju’s chain grade is designed to detect.

Review triggers

• A single coordinated mining entity sustaining more than 50% of observed hashpower
• A reorganisation deeper than six blocks
• A consensus split that leaves economically significant incompatible chains for more than 24 hours

Each trigger names a fact anyone can observe. If one occurs, Ketju will review the assessment again. None is a forecast.

Questions before use

1. Does the client’s thesis require censorship resistance, or primarily low-cost settlement?
2. Can the client withdraw without help from the party that normally orders transactions?
3. Who can upgrade bridges or contracts, and what delay applies?
4. Does the asset introduce an issuer weaker than the chain grade?
5. What evidence will show a halt, censorship event, or governance change?