how to proved the satoshi sent that claimed by the real buyer ? If someone see the tx id for ico address and claimed that tx id for their own ?
To simplify the investment process the steps just require to send me a PM with the txid. However, this method is exploitable by someone that just sit on the blockchain.info address page and wait for incoming tx. In this case (two or more users claiming the same transaction) i will request a signed message from an output address of the claimed transaction, or in case of an exchange wallet, a strong proof that can legitimate the statement of the user.