Double Spend

Double spending is when someone tries to use the same digital money for multiple payments, effectively tricking others into thinking they’ve been paid. Unlike physical cash, digital files can be copied easily, which creates a challenge for online currencies: how do you ensure digital money isn’t sent to more than one person at the same time?

This issue—known as the double spend problem—makes it crucial for digital currencies to prevent copying and reuse. If anyone could duplicate digital money, the whole system would become unreliable.

Bitcoin addresses this problem by using a public, decentralized ledger (the blockchain). Every transaction is recorded so everyone on the network can verify that coins haven’t been spent elsewhere. When bitcoin is sent, ownership is transferred and the transaction is logged, ensuring the same coins can’t be used again. This process stops double spending and keeps the system secure.