Bitcoin: How doable is a double expenditure attack?
Bitcoin, the world’s first decentralized cryptocurrency, has been around since 2009. While its applications are diverse, one of the most important concerns about Bitcoin is double expenditure attacks. In this article we will deal with the feasibility of such an attack and examine why it is important to understand the risks associated with Bitcoin.
What is a double expenditure attack?
A double expenditure attack occurs when a malignant actor spends two separate bitcoins out of his wallet, which leads to a loss for the sender and a profit for the attacker. This type of attack uses weaknesses in the underlying blockchain technology that enables double transactions.
Is a double expenditure attack feasible?
From a theoretical point of view, it is possible to create a double output scenario with Bitcoin. However, this would require a considerable amount of computing power and advanced cryptographic techniques.
In 2017, a group of researchers published a paper about the feasibility of double expenditure attacks in Bitcoin. They used a combination of mathematical algorithms and arithmetic simulations to demonstrate that it is theoretically possible to create a double expenditure attack with the current protocol design of Bitcoin.
The researchers found that with sufficient computing power and a large number of transactions, it is possible to create several identical transactions on the blockchain. However, this would require massive energy consumption, which is currently not economically not economically viable due to high electricity costs.
Why double expenditure attacks are highly unlikely
Several reasons help that double expenditure attacks are very impossible:
- Blockchain consensus mechanism : Bitcoin’s consensus mechanism is based on the collective effort of miners around the world to validate transactions and add the blockchain to new blocks. This ensures that every attempt to manipulate the blockchain is recognized by these nodes, which makes it practically impossible that a double output attack occurs.
- Cryptographic hash functions : Bitcoin uses extended cryptographic hash functions such as SHA-256 and KECCAK-256 to create unique digital signatures for any transaction. These functions ensure that no two identical transactions can lead to the same output, which makes it difficult for an attacker to create a double transaction.
- Transaction check : If a new transaction is transferred to the network, the miners check them using complex mathematical algorithms to ensure its validity and uniqueness. If several transactions are verified at the same time, attempts to manipulate the blockchain would be recognized.
Double double expenditure attacks
While double expenditure attacks are theoretically possible, the likelihood that they will occur is still important. In order to alleviate this risk, Bitcoin developers have implemented various measures, such as: B.:
- Mining performance : Miners use powerful computers to solve complex mathematical problems, which contributes to securing the blockchain and identifying all attempts at manipulation.
- Blockchain -validation : Cersecutors check transactions with several nodes in the network to ensure that every attempt to manipulate the blockchain is recognized.
- Transaction check : The SHA-256-Hash function ensures that each transaction has a unique outcome, which makes it difficult for an attacker to create double transactions.
Diploma
Although double expenditure attacks are theoretically possible, they are extremely unlikely due to the robust security mechanisms that prevent them. The consensus mechanism of Bitcoin, cryptographic hash functions and transaction check all contributes to its inherent security.