Double-spending is the concept that someone can replicate Bitcoin or cryptocurrency transactions with funds being sent to two different addresses simultaneously. The person responsible would then send a copy of the transaction to make it look genuine, or even delete the transaction altogether. For a digital currency to function reliably, there have to be strict mechanisms preventing this kind of behavior. This is because digital information can be relatively easily reproduced by tech-savvy individuals familiar with the blockchain network, and computing commands required to tamper with it.