Confirmations

What Are Confirmations?

When a cryptocurrency transaction is added to a block on the blockchain, it is deemed confirmed. Each subsequent block is an extra confirmation for that transaction. Because there is no central authority to enable cryptocurrency transactions, instead they are processed by the network as a whole or, more specifically, by miners. 

Miners then combine new transactions into blocks, secure them using the proof-of-work mechanism, and add them to the blockchain. A transaction (TX) must be communicated to the network before it can be added to the blockchain. 

Unconfirmed transactions are those that have been demanded by users but have still not been picked up by a miner and placed in a new block. Instead, they are collected in the mempool, a backlog of all currently unconfirmed TXs. 

When an unconfirmed transaction makes it into a newly mined block, it obtains one confirmation and becomes confirmed. Following that, each new block added to the chain serves as an extra confirmation for the transaction. So, if a TX was verified in block 656307 and the current block height is 656312, it has six confirmations.

Further Understanding the Concept of Confirmations

The number of confirmations is significant for security reasons. For example, suppose a hacker wishes to attack the blockchain by feeding it fake transaction data. In that case, they must first breach the security of every individual block in strict chronological order, initiating with the most recent one in the chain. 

The more blocks mined since a specific transaction occurred, the more difficult it is for a hacker to get through all of them and cancel that transaction. As a result, most crypto businesses that conduct customer transactions, like wallets and exchanges, require a minimum of three confirmations (or more, based on their policy) before accepting a transaction as genuinely valid and irreversible.