Bitcoin Forum

http://s23.postimg.org/hsi4iqzez/Question.jpg

I tired asking following question to some techie during Mumbai conference but seems like he wasn't able to understand the question. I'm seeking help for people who understand's Bitcoin and programming.

Scenario: Aman, Bobby, Charlie and Davis sends 1 Bitcoin to our hypothetical receiver(say Nakamoto) at 2 O'clock 29 minutes and 30 milliseconds( at very same time). Nakamoto knows those, four people are registered by filling a form on his website and has their details(name,age,sex etc).

Aman, Male, 24
Bobby, Male 19
Charlie, Female, 22
Bobby, Male, 45
...And IP address if programming is capable of extracting IP without user's knowledge when he's busy filling up form.

Task: Nakamoto has somehow managed to make people sign up form with details. All he knows is those details that are send by user(Name, sex and age + IP). He neither knows their wallet number nor any other detail. What he wishes is- when a person sends 1 Bitcoin to his wallet, his database automatically updates so that he knows that Aman send 1 Bitcoin from that wallet, Bobby send 1 Bitcoin.. and blah blah blah. He wishes his database(Name, age, sex) to be automatically update with users wallet details. Is it possible?

What I think problem is:
1. All Bitcoin's are send at same time.
2. I don't know whether Bitcoin are 'fungible' or not.
3. If Aman registers today, login's next day and sends Bitcoin next day. Won't it create confusion?

Firstly i dont  know  who  you asked this  question to  but  he  should  have been  able  to answer  this  question  if  he  know  jut  a  little  about  how  bitcoin  works.


Answer:--
Bitcoin  uses the public ledger system  to  keep  track  of  every transaction  down to  the  last Satoshi.

the receiver  would  need  to  get  the  public address of the  user when filling the  form. the  ip address  would not  be  be seen by the  receiver  from the bitcoin transaction, ckz it  p2p.

there are  are  ways  to track the  users  of a  specific address by doing  comparative analysis  of  the ip logs and the transaction on the blockchain.

but the simplest way to do this is  by having the user  jut add the public address on the form.
the other  was is to  use a browser cookie to track the  user and  have  a varying  amount added to the bitcoin transaction. the  amount being  unique to other transaction would revel the  users  public  address.

Normally Satoshi should assign a unique bitcoin address to each of these users, and they can send it on that address. The case is very simple than.

On other hand if you want other users to provide their bitcoin address here, it is also fine. But in the case of dispute you will have to ask them to prove them that they actually owns private keys of that address.

Regards

I do believe that what you are looking for is a callback that talks to your database and makes an entry into the relevant database and then assigns a payto address as mentioned by buysellbitco.in. This will help you get close to A man :)

In the event that a callback is not  passed and no unique address was generated, then there are ways to sniff the IP of incoming transactions from the other node, but to get the exact IP, you need to be the first to receive broadcast of the trx. This is not possible. Unless you have a layer around the node that is sending. If you can build a layer there, then IP matching should not be a problem at all.

Well i think what he asked is multiple transaction sent to one  address at the same time .

Tracking the addresses and identifying the user is what i think he wanted to find.

simple thing to do is to have every user  filling the form to also add their btc address.

By the way Benson how are you proposing to find the IP. i did not quite get that.

I tried asking same to International Bitcoin Community in Bitcoin Forum > Bitcoin > Project Development
Following is the thread:
https://bitcointalk.org/index.php?topic=383354.0

Well, I was able to understand a little bit from their technical discussion. See, if discussion might interest you. Someday, I'll discuss same project with you in person.   

By surrounding all nodes on the network and tracking where the coin was first sent from :D

That is impossible to do you would need to log each and every node and keep track of every new nodes that come into the network. How can that be done ?

subvolatil suggested: simple thing to do is to have every user  filling the form to also add their btc address.

It is not possible to ask user to give their address in fill up form. I don't want to make them suspicious, by asking private information and wallet information at same time. This is not working for me!

a btc address is not private information.

You can simply give them unique bitcoin address to send.


If you want to use single address for all deposits than you are complicating lot of things. For an example, say two users claim simultaneously deposit of 1 BTC. You can ask them to prove ownership of sending address. But that thing is very complicated as sometimes user does not have control over sending address ( Like when they send it from some exchange or coinbase ). This is the model satoshidice using with big fat warning that you must control sending address.

Regards

It can't be done, but here is some text that gets you thinking.

http://bitcoin.stackexchange.com/questions/7173/what-can-happen-if-when-a-node-is-surrounded-by-rogue-nodes

Bouncer! ::)

1. Technically speaking, I agree with subvolatil suggestion. During form filling, ask the user's BTC address and do the username to BTC address mapping internally.

If you want don't want to trouble the user during form fillup try the following.
(OR)
2. As buysellbitcoin suggested, autogenerate a new BTC address per user basis, and do the user to address mapping internally (Similar to cryptsy guys). Present this BTC address whenever an user is doing a transaction.
(OR)
3. Instead of autogenerating one BTC address per user(as mentioned in 2), autogenerate a new BTC address per transaction.  Present this BTC address whenever an user is doing a transaction.

Thanks everyone for guidance!

Techguy, if I generate new BTC address per transaction then, how am I going to accumulate wealth at one place. Then won't it be necessary to keep 'X' number of wallet address and 'X' number of private keys?

If you are really paranoid about the security, then per transaction-wise address is advisable otherwise go for per user address. You can use per transaction address in 2 ways.
1. As a throw away address --> Once the amount is being credited to this address, transfer the amount to your main address. Then you don't need to worry about securing the private keys of these addresses.
2. Longer life address --> Accumulate the diversified amount to a single address on need basis. But the problem here is, you need to gaurd your private keys in a safer manner.

Check this to autogenerate addresses:
http://procbits.com/2013/08/27/generating-a-bitcoin-address-with-javascript
https://www.bitaddress.org/

i would ask them to fill in their btc address or the say last  10 digits of it  when they are  signing up for your service
a btc address or even a partial one is not invading their privacy  or putting them at any risk :)

thats a simple solution to know who paid  and who didnt pay when the payments arrive at your wallet

I'm not bothered about payment here. I'm bothered about tracing identity or say linking details with their wallet address.Well, this is something that Bitcoin community won't like me to do. I'm just a dreamer.

Jhon Lenon- ....They may say, I'm a dreamer but I'm not the only one.... *Music*

Well when it comes to the bitcoin  community every idea is  accepted. Open discussion is how bitcoin  came into  existence.

you want to track identity. of a visitor in your website. right?

Now tell me  what all info  will you  ask from the user. and if the user will don any transaction in your  website?

Email/Name/Mobile is sufficient for me, but to distract them I'll be asking some more. I'm working on concept here. Nothing else! And no transaction will be done on website. :D

Well  in that case you  will have to  use a  tracking  cookie.  but  that wont  help much unless the user does a transaction on a website.

besides a  straightforward asking for the  bitcoin address. the only other way to get the address would be termed illegal and breach of user privacy

So in short  a  transaction should be made, may be on a  second website that can  recognize the  cookie form the  first website  you  filled the details in . (this too is  a  fine line  between privacy and breaking the law)

The other ways are illegal and will not  be  talked about.