The Bitcoin system is said to be robust. In other words, the transactions taking place in Bitcoin network follow a fullproof protocol to achieve the end result. The main question here is how are Bitcoin transactions verified? Let’s take a look at in more detail.
A typical Bitcoin transaction involves a transfer of Bitcoin value that is publicized to the network and accumulated into blocks. In other words, all Bitcoin transactions are noticeable in the blockchain and can be seen.
A couple of main elements in a block are the record of transactions and the Block Header. The Block Header is composed of the hash of the prevailing block and the hash of the prior block and many more important things. Approximately after every ten minutes, a new block is generated and attached to the blockchain. This process is done with the help of the mining process. This block validates and registers any fresh transactions and this is known as a confirmation of the transaction.
To verify, Bitcoin utilizes a Forth-like scripting system. In this, the entered scriptSig and the result scriptPubKey are estimated. After that, the input is verified if scriptPubKey is true.
For example, Jeff sends 200 BTC to Tom and Tom generates 100 BTC. Tom sends 110 BTC to Harry, and he wants to send himself some money. Harry sends the 110 BTC to someone else, but they haven’t obtained it yet. Only Harry’s output and Tom’s change are able to be used in the prevailing situation. In this way the Bitcoin transactions are verified.
In other words, each node saves a complete record of transactions. Now, when a node gets a request for a new transaction, it executes a sequence of checks to make sure that the transaction is legitimate. If John sends 5 bitcoin to Jeff, this transaction will be “unconfirmed” till the next block is generated. Once the next block is generated and the next new transaction is verified and added in the new block, the transaction will possess one confirmation. In this way the Bitcoin transactions are confirmed.