Can a Ethereum transaction has two or more address as senders like Bitcoin transactions?
My idea is use a smart contract to assign a transaction with two or more address, i.e. thinking in a intellectual property like a document where the related parties have to put owns public key to confirm that the document are yours. The register of the public keys has to be somewhere on that transaction.
I know that is possible to record the reported public keys in the "Input data" field of a transaction to have a proof of it.