The double-spending problem in blockchain refers to the risk of a digital currency being spent more than once. In traditional financial systems, transactions are verified by centralized authorities, such as banks, to prevent double-spending. However, in decentralized blockchain networks, there is no central authority to verify transactions. To address this issue, blockchain technology utilizes consensus algorithms, such as Proof of Work or Proof of Stake, to ensure that only valid transactions are added to the blockchain and prevent double-spending.
