Risk of double spending

A double spend occurs when someone sends a bitcoin tx, and then quickly sends another transaction using the same coins, but to a different receiving address. The network will ultimately only confirm one of the two transactions by adding it into a new block, so one of the receivers of a double-spent transactoin is at risk of not having their payment confirmed.

Some wallet software will watch for potential double spends, and issue a warning if one is detected. If you sent this transaction and know you did not double spend, then its probably just a false positive from the software, and you have nothing to worry about.

If you are the receiver of this transaction, do not release whatever goods/services you are trading the btc for until after this transaction has enough confirmations. Usually, 6 blocks is safe, but this number varies with the total value transacted (it is smart to wait longer for large transactions. Each block after the transaction has been mined is considered '1 confirmation').

chytrik

Posted 2017-12-07T02:01:23.203

Reputation: 10 276

Also the transaction never confirmed it’s been 10 hours am I at risk of losing $$? – Optii – 2017-12-07T02:41:30.313

Transactions are for the most part processed in order of fee rate, so if your tx has been pending confirmation that long, it likely has a lower fee rate than other txs being processed. Can you link the tx ID? – chytrik – 2017-12-07T02:49:18.587

There is no danger in having a transaction pending confirmation, though if it has a super low fee rate, eventually the majority of nodes may remove the tx from their mempool, and the coins would effectively be returned to their original owner. At that time, since the network nodes 'forgot' about the unconfirmed tx, the wallet controlling those coins can submit a new tx to spend them. – chytrik – 2017-12-07T02:51:08.790

What do I need to do in order to link the tx ID. Sorry I’m very knew to this – Optii – 2017-12-07T02:51:45.553

The wallet software should provide you with the tx ID, or you can just share the receiving address, its easy to find the tx ID with that. You can use blockchain explorer websites like blockchain.info to parse out this info. – chytrik – 2017-12-07T02:54:41.947

Ok one sec I’ll look up the recipient id – Optii – 2017-12-07T02:58:17.383

Your tx is fine, you can see here that the fee rate is 89.4 sat/byte (22.35 sat/wu). This link shows you what txs are in the mempool, yours would be somewhere in the blue 70-100 band, so the higher fee rate transactions above it will clear first. Right now the mempool is just very full (a lot of people have sent txs recently). Give it some time and it will confirm, how long it will take will depend on how busy the network remains, it is difficult to predict exactly.

– chytrik – 2017-12-07T09:25:35.530

Thanks but it’s been over 24hrs since I last did my transactions but it’s still haven’t confirmed – Optii – 2017-12-08T01:29:00.720

Look up RBF and CPFP, your wallet software may support these functions, so you could speed the tx up. You can also look up a transaction accelerator and use one of those to get it confirmed. Again though, there is no risk to just waiting, if it doesn't confirm within ~1 week, the network nodes will eventually remove it from their mempool, and your wallet will be able to send a new tx out. – chytrik – 2017-12-08T03:02:56.330

Would I be able to get my funds back if it doesn’t confirm? @chytrik – Optii – 2017-12-08T04:46:48.587

Yes, but 'getting them back' isn't really the right way to describe it. Right now, those coins still exist in your wallet as far as the blockchain is concerned. The blockchain is what matters, once your transaction is confirmed by a miner, it will be put in the blockchain for eternity. Until then, your signed tx is just waiting in the mempools of nodes around the world, once it has been confirmed the coins will have been spent. So if it doesnt confirm, the nodes forget about your transaction, & your wallet software will think it is okay to spend them again. – chytrik – 2017-12-08T08:54:10.737

Risk of double spending

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