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I've found a lot of information regarding orphan blocks, but I can't find an answer to this simple question.

If I send a payment to a user and my transaction happens to end up in an orphaned block, how will I recover my bitcoins? When the block-chain reorganizes itself and orphans the original block, will the client automatically add back my funds?

I've never encountered an orphan block so I have no clue how the transactions are resolved. Could someone please clarify what happens to the funds within these blocks?

Murch
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RLH
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  • I'm pretty sure the requirement of a block being orphaned is that another block with the same transactions but a higher hash value is found later. – bvpx Oct 22 '13 at 19:50
  • I could be wrong, but I'm not entirely sure that is the case. A block could contain, theoretically, hundreds of transactions. Assuming a pool manager decided to ignore transactions without transaction fees, I believe they could hash a much smaller block than another pool/miner. I could be wrong, but it's my high-level understanding that this could happen. – RLH Oct 22 '13 at 19:57
  • bvpx this is very very wrong, a block can ONLY be made invalid after inclusion if a longer chain which does not include the block becomes present https://en.bitcoin.it/wiki/Block_chain

    RLH is correct, a block does not need contain ANY transactions (I could say, not include transactions to any of bvpx's known addresses), but every transaction included must be valid or the whole block is invalidated (and the miner subsidy is lost, hence miners will not include invalid transactions).

     – Mark Aug 15 '14 at 17:59

1 Answers1

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Orphaned transactions are returned to the memory pool, they are never "lost". If the TX did cease to exist from the mempools, it would just be as if they has never been sent, so again they wouldn't be lost.

Anonymous
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    I guess this means people should generally keep their clients running even after sending a transaction that gets 1 confirm? Or does the miner who caused the extinct block take on the responsibility of broadcasting the lost transactions to the mempool? – bvpx Oct 22 '13 at 20:46
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    Every client that has the original block will add any transactions that aren't in the orphan-making block to their mempool, that usually includes most miners. Bitcoin-QT will rebroadcast any transactions of it's own that don't make it into any blocks too, usually with gaps of a few hours in-between. – Anonymous Oct 22 '13 at 20:50