BlockChain API to read Public note

[upal]

I am trying to read the Public note in a transaction, e.g.

https://blockchain.info/tx/114f37f3e30c7d9b5d5339e9a1652f2f065d0413fe34ee1121de0f21a50aaed3

Do u know the API for the same ?


p.s. I guess Public Note is a generic facility for transaction from any wallet, web or local machine. Please correct me if I am wrong.

[Sukrim]

You are wrong, this is just a proprietory service by blockchain. info. Messages are not part of the bitcoin  protocol.

[upal]

You are wrong, this is just a proprietory service by blockchain. info. Messages are not part of the bitcoin  protocol.

Thanks for correcting me. Is there any way we may mark a transaction with a text in Bitcoin protocol so that the receiver can identify the sender if there are multiple claimants to be sender ?

[Parazyd]

Nope. If everyone would put messages into the blockchain, it would make it even bigger.

[upal]

ok ...is the addr_tag part of the bitcoin protocol ?

[Parazyd]

https://en.bitcoin.it/wiki/Protocol_specification

You'll find everything there. You can't send messages the way you want. But you can sign messages.

[upal]

https://en.bitcoin.it/wiki/Protocol_specification

You'll find everything there. You can't send messages the way you want. But you can sign messages.

Thank u so much for the reference. I read the following 2...

i. https://en.bitcoin.it/wiki/Protocol_specification#Signatures
ii. https://en.bitcoin.it/wiki/Protocol_specification#tx

But could not identify a way to read any (signed) message from a tx. I think I am missing something. How do I identify sender of a transaction through API ? I mean, how a user of my system will prove that he/she is the one who made the transaction ?

[Parazyd]

You cannot sign messages in a transaction. You can sign messages as such (no correlation(?) to the blockchain).
So only the person that owns the address' private key can sign the message with that said address.

What you need to do is implement a system that will allow you to check if the signed message is valid.

[Envrin]

Starting with Bitcoind v0.9, which will hopefully be released shortly, you'll be allowed to include up to 80 bytes of data in a transaction, which gets stored in the blockchain.

[upal]

Thank u all. Can u plz help me out here => https://bitcointalk.org/index.php?topic=385733.0

[kjj]

You are wrong, this is just a proprietory service by blockchain. info. Messages are not part of the bitcoin  protocol.

Thanks for correcting me. Is there any way we may mark a transaction with a text in Bitcoin protocol so that the receiver can identify the sender if there are multiple claimants to be sender ?

Bitcoin is different.  You should not attempt to recreate obsolete systems in bitcoin.

Bitcoin has no sender.  You should not use this concept in your system.  If you need to identify someone, do it up front, before providing the payment address.  Then your problem is merely watching the address and checking the amount received.

[upal]

You are wrong, this is just a proprietory service by blockchain. info. Messages are not part of the bitcoin  protocol.

Thanks for correcting me. Is there any way we may mark a transaction with a text in Bitcoin protocol so that the receiver can identify the sender if there are multiple claimants to be sender ?

Bitcoin is different.  You should not attempt to recreate obsolete systems in bitcoin.

Bitcoin has no sender.  You should not use this concept in your system.  If you need to identify someone, do it up front, before providing the payment address.  Then your problem is merely watching the address and checking the amount received.

exactly that is what I am going to implement