Block Confirmation
Definition
The count of blocks added to the chain after the block containing a specific transaction. Higher confirmation counts mean greater computational cost to reverse the transaction, which translates to greater reliability as evidence.
- Domain
- Blockchain/cryptocurrency forensics
- Measures
- Number of blocks mined after the transaction's block
- Relationship
- Higher confirmations, harder to reverse via chain reorganisation
- Typical evidentiary threshold
- Varies by chain; commonly several confirmations before treating a transfer as final
Common questions
Why does an investigator wait for multiple confirmations before relying on a transaction?+
A transaction in a very recently mined block can theoretically be undone if a competing chain branch overtakes it, a rare event called a reorganisation. Each additional confirming block makes that reversal exponentially more computationally costly, so waiting for more confirmations reduces the risk of citing a transaction that later gets orphaned.
Does confirmation count prove who controls the sending address?+
No. Confirmations only establish that the transaction is durably recorded on the ledger; they say nothing about the real-world identity behind the address. Attribution requires separate work such as exchange KYC records, IP correlation, or clustering analysis.
Related terms
- Account Model
- Ethereum's approach, where each address holds a running balance incremented or decremented by transactions. Simpler to reason about but less transparent about...
- Distributed Ledger
- A transaction record replicated across many independent nodes. Each node holds a full or partial copy and validates new entries against the...
- Private (Permissioned) Blockchain
- A network where participation is restricted to known, approved nodes. Used by banks and supply chains for transaction settlement. Records are not...
- Public Blockchain
- A permissionless network where anyone can read the ledger, submit transactions, or run a node. Bitcoin and Ethereum are public. The ledger...
- UTXO (Unspent Transaction Output)
- The fundamental accounting unit of the Bitcoin protocol. Each transaction consumes previous UTXOs as inputs and creates new UTXOs as outputs. The...