Is it possible to verify multiple accounts' attached main parent user?

Question

[Q] Is there any unique ID for geth or parity usage, which might help use to detect multiple created accounts' main parent creator? (I assume all those multiple accounts are created by the same main user, using the same geth node).

For example, using a geth or parity node same user can create multiple accounts which are attach to actually one user. If there is unique geth or parity ID, maybe that might help us the identify all created accounts are actually attach to one user using the linked to the same geth or parity node where accounts are created.

Another example: we wrote contracts for voting using msg.sender for voters. I realise that a user can create many dummy users, which he could use them to vote for himself. We cannot prevent this from happening since each ethereum account is different from each other.

       function becomeMemberCandidate(bytes32 ipfsHash) public
        not_member returns(bool) {

        members[msg.sender] = uint32(membersInfo.length); //contains addresses which can vote within the contract.
        memberAddresses.push( msg.sender ); 
        return true; 
    }

Answer 1

I don't think it would be desirable to be able to link multiple externally owned accounts to a single user, or to a single node, for reasons of privacy.

From the perspective of contract accounts, you could have a look at a general factory pattern, whereby a parent factory contract could create multiple identical child contracts. The creation of the child contracts could then be traced to the parent, and so on.

See: Is There a Simple Contract Factory Pattern?