Bitcoin Forum

Bitcoin => Development & Technical Discussion => Topic started by: nFast on October 18, 2012, 07:37:06 PM



Title: Mining the blockchain :)
Post by: nFast on October 18, 2012, 07:37:06 PM
Hi there,

I've just watched a presentation on youtube about data mining
the BitCoin block chain.  The presenter said that it is possible to
build up a graph that shows transactions between people.  I was
wandering if it is really possible, because AFAIK every time I send
bitcoins, the standard client uses a shiny new address. Please correct
me if I'm wrong, but the block chain contains only address->address
relations as the coins go from one address to another.  If source
addresses are always replaced with a new one after every transaction
(what's more, I can use as many addresses as receiver addresses as
I want), this graph will only show two type of figures:  single lines
between two points without any other relationships with other addresses,
and "stars", I mean single addresses, that receive money from more
than one addresses, but the senders won't have any other connections,
and the destination address will never appear in a transaction where
it is the source address.  Am I right?  Or do I missed something here?

Is there any other info in the blockchain that can be used?  There must
be the source address, the destination address and the amount.  Maybe
the transaction fee, but what else?


PS:  okay, maybe there's one case when an address can be a source
and a destination too.  When someone starts up a new wallet, and it
contains a default address, and s/he sends this address to others to
receive money.  Maybe in this case it is possible that the client will
lates use this address as a source address when the owner of the
wallet does her first outgoing transaction.


Title: Re: Mining the blockchain :)
Post by: Stephen Gornick on October 18, 2012, 10:46:35 PM
The presenter said that it is possible to build up a graph that shows transactions between people.

Bitcoin can be used in a manner that protects your privacy.  Every bitcoin transaction is traceable though, so without taking protective measures, there is information that can be gleamed from the blockchain.
 
 - http://en.bitcoin.it/wiki/Anonymity

There is an effort to provide the associations:

 - http://toolongdidntread.com

The site, BlockViewer is offline currently, but it was showing some of these associations between people who were careless with their information (e.g., used static addresses) and/or weren't protecting their activity from this type of flow analysis.

 - http://blockviewer.com



Title: Re: Mining the blockchain :)
Post by: hamdi on October 19, 2012, 01:38:27 AM
blockchain.info has extremely nice diagrams and stats. go have a look there.


Title: Re: Mining the blockchain :)
Post by: capsqrl on October 20, 2012, 05:01:04 PM
I've just watched a presentation on youtube about data mining
the BitCoin block chain.
No link?