double spending [English]
No definition in earlier IP projects. ITrust definition not yet developed.
- Bitcoin Developer Glossary 2017 (†791 s.v. "Double spend"): A transaction that uses the same input as an already broadcast transaction. The attempt of duplication, deceit, or conversion, will be adjudicated when only one of the transactions is recorded in the blockchain.
- Bitcoin Group  (†846 s.v. "Double spending"): The act of spending bitcoins twice. It happens when someone makes a transaction using bitcoins, and then makes a second purchase from someone else, using the same bitcoins. They then convince the rest of the network to confirm only one of the transactions by hashing it in a block. Double spending is not easy to do, thanks to the way that the bitcoin network operates, but it is nevertheless a risk run by those accepting zero-confirmation transactions.
- Bitcoin Wiki Vocabulary  (†796 s.v. "Double-spending"): Double-spending is the result of successfully spending some money more than once. Bitcoin protects against double spending by verifying each transaction added to the block chain to ensure that the inputs for the transaction had not previously already been spent.
- Blockchain Technologies 2016 (†789 s.v. "Double Spend"): Double spend refers to a scenario, in the Bitcoin network, where someone tries to send a bitcoin transaction to two different recipients at the same time. However, once a bitcoin transaction is confirmed, it makes it nearly impossible to double spend it. The more confirmations that a particular transaction has, the harder it becomes to double spend the bitcoins.
- BlockchainHub Glossary (†807 s.v. "Double Spending"): Double-spending is the result of successfully spending some money more than once. Bitcoin is the first to implemented a solution in early 2009 which protects against double spending by verifying each transaction added to the blockchain to ensure that the inputs for the transaction had not previously already been spent.
- Scaling Bitcoin  (†845 s.v. "Double spending"): Double-spending is a failure mode of digital cash schemes, when it is possible to spend a single digital token twice. Since, unlike physical token money such as coins, electronic files can be duplicated, and hence the act of spending a digital coin does not remove its data from the ownership of the original holder, some other means are needed to prevent double-spending.