You are viewing a single comment's thread from:

RE: Getting in to ICOs - A Guide and Some Tips & Tricks

in #ethereum7 years ago

I should also add that transaction data used to interact with the ICO contract may be required to know ahead of time. Unfortunately, it's often unclear what exactly you need until the ICO has already begun.

Sort:  

If identical copies of a signed transaction are sent twice to an ico contract and both go through, would both transactions be executed or would the second copy be rejected as a duplicate ?

Each address has a nonce, a number that begins at zero and is incremented after every processed transaction.

Each transaction also has a nonce. Part of signing the transaction requires the address to have exactly the same nonce of the transaction. This forces all transactions to occur in the order sent, and also prevents a duplicate transactions.