It is extremely difficult to reverse or modify a transaction after it has been recorded on a blockchain. One of the most fundamental aspects of blockchain is that it cannot be altered. This provides the network with trust and security. Due to the decentralised and distributed nature of blockchain technology, it is practically difficult for a single entity to change or reverse transactions.
The blockchain is founded on the concept of agreement, which occurs when many nodes in the network verify and agree that a transaction is valid. When a transaction is accepted and added to a block, it is cryptographically connected to the blocks before it. This results in the blockchain, which is a chain of blocks. This ensures that the transaction information is correct and unchangeable.
Technically, it is possible to undo a transaction, but it would need a significant amount of computer power and control over the majority of the network’s nodes. In the case of a Proof of Work blockchain, this would mean employing a 51% attack, in which an attacker seizes more than 50% of the network’s hashing power. However, such an attack is unrealistic and requires a large amount of resources, making it costly and difficult to organise in most cases.
It is critical to note that once a blockchain transaction has been approved and added to the chain, it cannot be reversed. This ensures the system’s trustworthiness and makes blockchain a viable tool for things like financial transactions, supply chain management, and owning digital goods.
However, if a mistake or fraud occurs during a transaction, it is advisable to address the issue in another method, such as contacting the people involved, going to court, or using the tools provided by the blockchain platform or service.