You might find this useful: https://bitcointalk.org/index.php?topic=94102.0

(the other choice is to use an alternative client)

btw - in regards to WoT I had previously posted some thoughts regarding using the blockchain here: https://bitcointalk.org/index.php?topic=87339.0

Sure - the idea of identifying a person uniquely is very different concept from creating a WoT (although it may actually be possible to use the blockchain technology to do both things).

For sure a WoT is the key thing for doing trading with other entities.

Identifying individuals is only critical if we want to be able to support a democratic style of voting in a de-centralised manner (something I think would be an amazing feat to achieve).

Indeed that was my thinking behind having 2 private keys (one that only the actual person has) - also I guess a registry of dead identities would be required (yes rather impossible with fingerprints if they were burned beyond recognition - DNA?).

Interesting stuff (and makes Namecoin look more relevant), however, the problem when it comes to voting is one can create multiple identities and AFAICT this is the #1 problem that is so far lacking a de-centralised solution (hence why I threw out the bio-recognition idea).

Ouch - am now having nightmare visions of people turning up to voting booths with bags of eyeballs and fingers. 

One very interesting technology that comes to my mind with regards to this issue is open source 3D printing (although the possibility of using this tech to create such devices is probably a long way away).

Without a doubt trying to uniquely identify someone and then allow that person (and only that person) to perform a tx in a way that cannot later be deconstructed to then identify them is one very difficult problem (so any solution I think is going to be somewhat messy).


Also for sure I don't know anything about how actual fingerprint software operates. I was really just trying to put out an idea that perhaps someone else could work out (or perhaps just disprove if what I'm suggesting is not actually theoretically possible).

Yup - for the key to be useful to identify a single individual the actual "fingerprint" would in fact already have to be some sort of hash that would be used for comparing fingerprints (rather than the raw scan data which of course would vary).

I was assuming this is how fingerprint DB's for forensics worked (but must admit I haven't researched it at all).

Yeah - the idea of having 2 keys (or a 2 part private key) would be to stop any usage of the fingerprint key without also having the other private key.

Although I guess if you were about to get your fingers cut off you might end up divulging your other key.

Yup - complicated private key issues aside the hardware would be a much more difficult trust issue for such a system (but necessary in the approach I was outlining to ensure that no-one can cheat).

One weakness I can now see in my idea (which admittedly just came off the top of my head) is that if someone did manage to get your fingerprint then they would be able to work out who you had voted for (as the public key would be easily traced).

It may be possible, however, to circumvent this problem by using the sort of combining private key stuff that etotheipi has described before for safely being able to generate vanity addresses for other people (this needs some more thought).

One idea that came to my mind was the following:

SHA2( fingerprint information ) == private key 1
SHA2( some pass phrase or personal info ) == private key 2

1) Import the private keys into your wallet then send perhaps a specific BTC amount to both addresses (the sending could be done from anywhere to hide IP). The purpose of this is to be able to find the public key of all registered voters (and to be able to prove you have registered to vote). Also to ensure that no other public key #2 can be used with public key #1 (i.e. identity theft).

2) To prove identity a fingerprint scan would be performed and then public key #2 would be determine from the registration txs in the block chain (of course you need to trust that the device checking the fingerprint only actually outputs the public key and does not keep the raw data and that you were not photographed using the device, etc.).

3) A voting token (say BTC0.001) is sent in a tx that will require two sigs (for the 2 keys).

4) Some time later (and most likely at a different physical location) you can "spend" your vote.

From that thread there was a link to this: https://github.com/weex/bitcoind-centos in which the README contains the following:


Are you using the same version?

Well the wallet would need to be on the server, however, if it has been encrypted then the private keys should be safe (as the listtransactions command doesn't actually need to see the private keys to work).

I think what you are probably going to need to study is this: https://en.bitcoin.it/wiki/Original_Bitcoin_client/API_Calls_list

You can use the "bitcoind" console interface to check for recent transactions (see the command *listtransactions*) which you could schedule to run at regular intervals (you just then need to be able to parse the returned JSON formatted data).

The following is a simple usage example:

The addresses contain a "checksum" at the end so if the address if you put in an invalid address then that will be detected and no sending will occur. If you put in the *wrong* address (but one that is *valid*) then bad luck - bitcoins are gone (so be careful)!


No problem to do that at all.


I don't think the client actually has any way to delete an address but if you were to somehow *lose* the private key to an address you would effectively no longer own that address (and likely nor would anyone else).


A very huge number - so big that the chance of any collision (or *birthday*) is probably less likely than our entire universe being a computer simulation.


Just change the "keypool=<n>" setting in bitcoin.conf to 2000 (and restart the client).


Yes - and also http://blockchain.info.


Not sure why you would want to use a 3rd party to be doing this as the client itself will tell you when you each tx is received automatically (so no need to use a website or service for that).


HTH,

Ian.

The "age" of the coins is another factor in the calculation of the tx fee (this is to stop people from creating a DoS attack by constantly spamming the network with very small amounts).

If you wait long enough you'll find that the fee is no longer required.

Unfortunately if they are anything like the equivalent Office of Fair Trading in Victoria you'll likely get no help from them at all (they basically don't take the consumers side but instead are on the side of the businesses).

Understood but perhaps we could just have just one more little option for choosing whether to display it.