Using Infura Transactions

After reading and using Transactions from Infura I run into a few doubt.
I’ve read the documentation:

However, I though I could just relay in a given address for me that only runs my transactions. But I can’t trust the address because other users from Infura could use them, and there is not even a address list.

So…, how do I trust that the sent transactions are mine?
I just want to use Infura transactions to send the “server” transactions, so no need to relay user transactions.

hi @insofu, you could have your smart contract verify a signed message (and not use msg.sender) and then you could just pass a signed message to the contract and it wouldn’t matter who actually sent it.
Check this out: Transactions - Infura Docs

Thanks,
Traian

I’ve seen that. But I can’t find a proper example in Solidity to verify the signed message which correspond to the given example in the docs.