In the blockchain, every transaction has a transactionId where does this come from?
2 Answers
TXID is the double sha256 hash of the signed transaction, used to uniquely identify a particular transaction.
When you create/sign a transaction that hash will be generated with your transaction.
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So it's the digital signature? Is there a comprehensive website that I can use to read up on bitcoin? From a programmers point of view. Mar 15, 2018 at 20:28
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Yeah, There's a book called Mastering Bitcoin by Andreas Antonopoulos , Best book ever.– TailerMar 15, 2018 at 20:29
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If TxId is the hash of the transaction data, how it is made unique to guard against fraudulent duplicate transactions (including timestamp)? Dec 27, 2020 at 14:40
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@HiranmayGhosh: The output of cryptographic hash functions is collision resistant and 2^256 is a huge space of numbers.– Murch ♦Dec 27, 2020 at 17:02
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