Topic: Is it possible to have two transaction IDs that are exactly the same? (Read 2802 times)
You can maliciously, or stupidly, create two transactions with the same ID. The easiest way is to mine two blocks and include in each one only a single transaction -- the coinbase transaction, with the same payout address, same payout amount, and the same coinbase.
July 13, 2011, 03:44:02 AM
It is possible (though very rare) for the exact same transaction to appear twice in the block chain, however.
Can you please explain under what circumstances this could happen? I couldn't find anything.
July 12, 2011, 11:58:37 PM
Transaction IDs are SHA-256 hashes of transactions. It's very safe to use them as unique IDs, and it's a waste of time to try to detect collisions.
It is possible (though very rare) for the exact same transaction to appear twice in the block chain, however.
It is possible (though very rare) for the exact same transaction to appear twice in the block chain, however.
July 12, 2011, 11:44:26 PM
Thanks for that.
That's what I thought.
Since blockexplorer allows you to search by transaction id... you should not be able to have a duplicate one I would think.
That's what I thought.
Since blockexplorer allows you to search by transaction id... you should not be able to have a duplicate one I would think.
July 12, 2011, 09:50:21 PM
Yes, it is possible... But is very very very unprobable. They are more possible directions that atoms on the hole earth, but im not really sure.
July 12, 2011, 09:20:18 PM
Or would that be considered a collision of some sort? What exactly is a transaction id? A hash of some sort I presume?
I couldn't find much about transaction ids in particular on the wiki.
How would the bitcoin client treat two separate transactions with identical transaction ids?
I couldn't find much about transaction ids in particular on the wiki.
How would the bitcoin client treat two separate transactions with identical transaction ids?
Jump to: