Is it possible to know if an address is owned by blockchain.info?

[glub0x]

So, couple years ago i gave 0,5 btc to someone.
Now we have some trouble to access them. I belive he made an account on blockchain.info and gave me his public address.
So here is my questions:
-I have the public adress, Is it possible to verify that it is on blockchain.info so i don't waste my time to try to find his ID?
-He only have one e-mail address. Was it possible before to register on blockchain.info without giving your e-mail? Blockchain's Id recovery doesn't send him his Id ...

Thanks

[TryNinja]

-I have the public adress, Is it possible to verify that it is on blockchain.info so i don't waste my time to try to find his ID?

When you say public address are you talking about the Bitcoin address? If so, you can't get a ID/Email or even any info from the address itself.

-He only have one e-mail address. Was it possible before to register on blockchain.info without giving your e-mail? Blockchain's Id recovery doesn't send him his Id ...

I can't remember but if he doesn't have his ID and he can't recover with any email, then there is no way to find out his ID. Sorry =/

The only thing you guys can do is try to find his ID in any PC/Email he had in the time he owned that wallet.

[glub0x]

-I have the public adress, Is it possible to verify that it is on blockchain.info so i don't waste my time to try to find his ID?

When you say public address are you talking about the Bitcoin address? If so, you can't get a ID/Email or even any info from the address itself.

Yes i have the bitcoin public address. From itself i know i can't get anything, but some address are tagged as belonging to some company  like mtgox's one for instance.
Maybe there is  a way for blockchain.info to say "yes this is the public address of a webwallet we have" this way it narrow our search...


Now i realise that blockchain.info doesn't double check if your e-mail is valid. So i realise maybe he miss-spelled his e-mail address ...

[ranochigo]

It is actually to deduce, up to a certain degree of certainty that the address belongs to a Blockchain.info wallet. Has he made any transactions from that address?

You have to get the a transaction ID that spends the coin from that address. Blockchain.info does have a feature which says where the transactions are first relayed by. This is mostly inaccurate but for their Blockchain wallet, the relayed by will be shown as Blockchain.info as opposed to a random IP address.

[232drialf]

You can also use: https://www.walletexplorer.com/

It is not always accurate but mostly it works for the big companies from bitcoin area.

[glub0x]

Ok so i can't find anything!

I belive i sent him from my old mtgox account to this address
1YEnZd4y1LYXy8egBc3ZCsi2vpuPutQFa
then he made a transaction to test bitcoin sending this address
129KL2hPChjcNKWvvZYUtmXgChhWPyZvSW


and nothing happen... I belive this is a blockchain.info address but i am not sure.

[ranochigo]

You can also use: https://www.walletexplorer.com/

It is not always accurate but mostly it works for the big companies from bitcoin area.

It doesn't really work for a lot of online wallets. It only works because the addresses are sending funds to a known cold storage/hot wallet that is controlled by the said companies. Else, there is no way for them to identify where the address came from.
1YEnZd4y1LYXy8egBc3ZCsi2vpuPutQFa Doesn't look like a blockchain.info wallet address to me. Of course I can be wrong but I am almost certain about it.