2023-09-08clock5 minutes

A frequent issue in the Digital World - Double Spending

Prior to the emergence of Bitcoin by the enigmatic Satoshi Nakamoto, numerous individuals and enthusiasts endeavored to establish decentralized payment systems. However, all of these attempts were hindered by the obstacle of double spending.

We found ways to solve the problem years later.

Through this blog, we're here to demystify a prevalent issue in the digital realm known as double spending. Join us as we explore how blockchain technology offers a solution to this challenge.

What is a Double Spending problem in Cryptocurrencies?

A significant hurdle in establishing a resilient financial system revolved around devising a decentralized framework in which transactions could be validated. This assurance of authentication aimed to prevent the occurrence of double spending, ensuring that a unit of currency wouldn't be expended more than once.

A centralized payment system solves this problem through a special confirmation mechanism for each transaction, and thus avoids double spending.

Double spending pertains to the act of utilizing the same asset multiple times. In the realm of cryptocurrencies, the double-spending problem materializes when a sender dispatches an identical amount of assets to multiple recipients in quick succession, before the initial transaction is confirmed and officially recorded within a blockchain block.

To understand the situation and the problem of double spending, it is better to use an example:

Picture this: In the physical world, when someone buys a coffee and hands over 5 GEL, that money finds its place in the coffee company's cash register. It's an irrefutable fact that the same money can't be spent again. However, cryptocurrencies defy this tangible limitation since they're digital entities, and transactions occur in the digital realm. Consequently, until a transaction is verified and executed, it lingers within the sender's wallet. This dynamic sets the stage for a scenario wherein the user might utilize the same asset for a second time within the window before the transaction secures confirmation.

How to solve the Double Spending problem in Crypto?

There are some mechanisms to solve the double spending problem in blockchain technology and cryptocurrencies:

  • Open Register of Transactions
  • Special mechanism of Confirmation

Within blockchain technology, no data is lost, and every single transaction is meticulously recorded within a block. Each subsequent block effectively encapsulates the lineage of prior transactions. As a result, each transfer is allocated a distinct timestamp that marks the moment of its execution. This chronological organization empowers the system to differentiate between authentic transactions and their duplications.

A person, driven by dubious intentions, seeks to exploit a vulnerability to profit from their assets twofold. To illustrate, suppose they possess 1 bitcoin in their wallet. They initiate a transaction to one destination, but before this transaction gains confirmation, they orchestrate a parallel action—sending an identical number of bitcoins to another address. This cunning maneuver is essentially an attempt at double spending.

Both transfers are automatically added to the queue of pending transactions awaiting confirmation. These transactions undergo sequential scrutiny, wherein they are meticulously verified and either approved or disapproved. Once the initial transfer secures confirmation, it attains a verified status, while the second transaction, which mimics the identical information, undergoes assessment by multiple validators. Consequently, it fails to garner consensus and is consequently rejected.

The recipient on the receiving end of the transaction will exercise caution and only proceed to provide the relevant product or asset to the buyer once the transaction attains credit through confirmation. It's important to note that after undergoing a sequence of six confirmations, the transaction achieves a state of security, thereby alleviating concerns regarding potential double spending complications.

If you are interested in how to track your Crypto Transaction and check how many verification steps it passed, read our blog.

Summary: Double Spending problem is Solved

Cryptocurrencies and the innovation of blockchain technology have achieved a remarkable feat that the conventional financial system struggled to overcome - the successful resolution of the double spending predicament.

Thanks to the existence of the Open Register of Transactions, where records endure indefinitely within blocks, and the implementation of a dedicated validation mechanism involving a multitude of miners and network participants scrutinizing each transaction for authenticity, the issue of double spending has been effectively relegated to history.