FOLLOW THE MECHANISM
- 1Pending
A node has seen the instruction.
- 2Included
The current chain contains the execution.
- 3Confirmed or finalized
Network-specific settlement conditions are met.
- 4Credited
A receiving application applies its own availability policy.
A conceptual sequence. Real implementations can add steps, intermediaries, and conditions.
Three questions to keep separate
Was the instruction accepted for relay? Was it included and executed in the chain currently followed? How difficult is it for that result to be displaced? These are separate questions. A wallet may simplify them into “pending” and “complete,” while a custodian applies its own deposit-crediting rule. A service’s operational decision is not itself a consensus guarantee, and different receiving systems can legitimately wait for different confidence levels.
Bitcoin accumulates probabilistic confidence
Bitcoin selects the valid history with the greatest accumulated proof of work. A block buried under more work becomes harder to replace for an attacker with limited resources. Confirmations count the containing block and subsequent blocks, but they do not create absolute mathematical irreversibility. The relevant threat assumptions include adversarial hashing power, network connectivity and the value at risk. An average block interval is not a deadline.
Ethereum adds checkpoint finality
Ethereum’s Gasper combines a rule for following the current head with stake-weighted checkpoint justification and finalization. Finality relies on a supermajority of the relevant stake voting under the protocol’s conditions. Conflicting finalized histories would imply serious consensus failure and slashable behavior under the model. Finality may stall during disruption even while blocks continue to appear, so continuing block production and continuing finalization are not identical observations.
Connected systems add their own delays
An exchange can wait after network finality before crediting a deposit. A rollup may expose a fast sequencer acknowledgement before its data and proof or challenge conditions settle on a base chain. A bridge can add verification and release procedures. Following a complete transfer therefore requires naming the settlement layer at each step. “Final on chain A” does not automatically mean an asset is withdrawable through every dependent system.
MAKE IT CONCRETE
A deposit can be final and unavailable
An illustrative exchange waits for its chosen network settlement threshold, then pauses withdrawals for maintenance. The deposit’s chain history can remain final while the customer cannot move the exchange balance. That problem belongs to custody and operational availability. Waiting for more blocks does not by itself resolve it.
FAILURE PATHS & COMMON MISREADINGS
Where the model can break
- There is no single confirmation count appropriate for every network or consequence.
- A reorganization affects accepted history; an application outage need not.
KEEP EXPLORING