62. On Short Messages in the Block Chain

62

On Short Messages in the Block Chain

THE BLOCK CHAIN is the public ledger of all bitcoin transactions and is shared within the peer-to-peer network. At present, it contains only the transactions themselves. In this thread, someone proposes adding another piece of information within each transaction contained in the block chain that would be the equivalent of the “Note” section on bank checks. Unlike these, however, this note would be public and so visible to all. Satoshi expressed concerned that someone could publish in this note some information that was meant to be kept private, such as a customer account number.

Nevertheless, this feature is currently being considered for a future update of Bitcoin but is not yet available as of this writing. For now, only a third party service such as blockchain.info allows users to add extra text information, but it is not part of the block chain itself.

Miners have the ability to add some extra text in the block. As a matter of fact, the very first block created by Satoshi Nakamoto, block 0, has the following message in it:

“The Times 03/Jan/2009 Chancellor on brink of second bailout for banks”

The message is in ASCII encoded form but easy to extract for those who know how.

Suggestion: Allow short messages to be sent together with bitcoins ?

Posted by ShadowOfHarbringer, October 23, 2010,03:11:17 PM

Bitcoin is great, but it misses one thing that usual bank transfers have: payment title.

Perhaps it should be possible to include short (<=512 bytes)message for each transaction.

The message could be encrypted with public/private keys so only the receiver can see its contents.

What do You think ?

PS. I might be wrong, but the messages could also be used to increase randomness of hashing process by the way, couldn’t they ? If not, never mind.

Re: Suggestion: Allow short messages to be sent together with bitcoins ?

Posted by satoshi, October 23, 2010, 07:02:57 PM

ECDSA can’t encrypt messages, only sign signatures.

It would be unwise to have permanently recorded plaintext messages for everyone to see. It would be an accident waiting to happen.

If there’s going to be a message system, it should be a separate system parallel to the bitcoin network. Messages should not be recorded in the block chain. The messages could be signed with the bitcoin address keypairs to prove who they’re from.