<p>Yes &amp; No</p>

<p>You can track a person's transaction only if you know that person's wallet address/es</p>

<p>By the wallet address/es, you can see the transaction.</p>

<p>The incoming transaction can be a buy, or a sale completed, etc.</p>

<p>The outgoing transaction can be a sell, or a purchase, etc.</p>

<p>You can also track a person using all his xpub key to know all the address/es at once.</p>

<p>Buy you cannot track a person just with a name or a single wallet address (if he owns multiple, which at this time, people do).</p>

<p>Hope this answers your question.</p>

CC BY-SA 3.0
2018-03-09T13:29:40.543Z
Suppose I was not interested in the identity of the person, but I was interested in tracking an ID. In other words, I don't care about Mr. Smith as such, but I want to isolate Mr. Smith's trades, and analyze them seperately from Mr. Jones'. Is that possible?
user120911
CC BY-SA 3.0
2018-03-09T15:12:25.970Z
Still the answer would be a yes and no. Yes, if you know his xpub key and he only makes wallet from that xpub key. No, if he have multiple accounts (which is the case in normal scenario)
remedcu
CC BY-SA 3.0
2018-02-09T18:10:01.853Z
2018-02-09T18:10:01.853Z
remedcu
<h1>Is there information about the buyer and seller in the Blockchain?</h1>

<p>Private information, no. Public information, yes. A transaction contains the input addresses (utxo's), public keys, output addresses and, the change address. None of these is stored with any private information on the blockchain and, even the different input or output addresses are not linked in any meaningful way apart from their association in an individual transaction.</p>

<p>Ordinarily, change will be sent back to a different receiving address than the inputs used to fund the transaction, and there is no way to distinguish a change address from any other outputs. Even to determine which of the outputs is the spend output and which is the change address back to the sender (if any) is at best a guess.</p>

<p>Occasionally, a user may be using a wallet configured without the ability to create new addresses. In this case change goes back to one of the input addresses, however, apart from that one address we still have no idea how many additional addresses the user may have with a balance in their wallet, they are not linked.</p>

<h2>Suppose I wanted to track transactions by an individual entity in the Blockchain, say Mr. Smith. Is that possible?</h2>

<p>The best you could hope to achieve without guessing is to determine the specific balance of specific addresses but with no way to link those together to understand wallet or user balances. No, that is not possible unless Mr. Smith discloses ownership of all of his addresses and you can find that information to link them.</p>

<h2>I will revise my question slightly: Suppose I was not interested in the identity of the person, but I was interested in tracking an ID. In other words, I don't care about Mr. Smith as such, but I want to isolate Mr. Smith's trades, and analyze them separately from Mr. Jones'. Is that possible?</h2>

<p>Given the above, no. There is no way to know which outputs are directed to any particular user, so you cannot then know who is spending. Even if you follow a transaction chain from output, to input, to output, you have no way to know when any BTC has changed hands.</p>

CC BY-SA 3.0
2018-03-10T01:34:18.087Z
2018-03-10T01:34:18.087Z
Willtech
<p>Privacy is one of Bitcoin features. Regardless of the infrastructure that wallets follow to protect user privacy.</p>

<p>generating a new address for each transaction is a must. </p>

<p>Even if you have Mr.Smith Address. You will never get full and accurate information about his total balance or his contacts.</p>

<p>What if Mr.Smith address is belonging to an exchange? You are tracking the wrong person.</p>

CC BY-SA 3.0
2018-02-09T23:04:05.607Z
2018-02-09T23:04:05.607Z
Tailer
<p>The question is very generic ... as such: No.. There are only addresses, pubkeys and address hashes visible. No names. But (!): assuming you buy s.th. at Amazon with your address, then Amazon knows about the link between address and name (to send the goods to). And we know,that data protection is not their main focus :-)</p>

<p>This is the reason why you want to use addresses only once.</p>

CC BY-SA 3.0
2018-02-09T18:14:33.973Z
2018-02-09T18:14:33.973Z
pebwindkraft
<p>Bitcoin means that the people are action pseudonomously. It's almost impossible to find out who is the owner of a random address.</p>

<p>But if you know the pseudonym (if you know that Mr. Smith has address XY), you can track every transaction to/from this address.</p>

CC BY-SA 3.0
2018-02-09T18:11:54.453Z
2018-02-09T18:11:54.453Z
hardfork
<p>No, not really.  The blockchain tracks which transactions are comprised of outputs of previous transactions.  Since a transaction can have multiple inputs (pointing to the outputs of previous transactions) and outputs, each transaction can be paid from multiple people and paid to multiple people.  The addresses, themselves, have no association on the blockchain with any person or organization.  The blockchain simply doesn't store data on users.</p>

<p>However, if you were able to supplement the blockchain with data on who owns which address, you could to a certain degree of accuracy determine where money is coming from and where it is going.  Best privacy practices, however, make this more difficult...even <em>if</em> you have data to supplement the blockchain with.  This is why we say that Bitcoin is "pseudonymous".  You can track how money flows, but not the people/entities behind the movement.</p>

CC BY-SA 3.0
2018-02-09T18:15:36.340Z
2018-02-09T18:15:36.340Z
Jestin
<p>Suppose I wanted to track transactions by an individual entity in the Blockchain, say Mr. Smith. Is that possible?</p>

CC BY-SA 3.0
2018-02-11T05:35:53.813Z
Welcome to Bitcoin.SE! You ask a serious question and I see you have several good answers already. Good luck!
Willtech
CC BY-SA 3.0
2018-03-09T13:30:28.980Z
I will revise my question slightly:

Suppose I was not interested in the identity of the person, but I was interested in tracking an ID. In other words, I don't care about Mr. Smith as such, but I want to isolate Mr. Smith's trades, and analyze them seperately from Mr. Jones'. Is that possible?
user120911
<traceability>
Is there information about the buyer and seller in the Blockchain?
user120911
# Is there information about the buyer and seller in the Blockchain?

(Asked by: username_0 on 2018-02-09)

Suppose I wanted to track transactions by an individual entity in the Blockchain, say Mr. Smith. Is that possible?

**Tags:** traceability

> **Comments:**
> **username_1**: Welcome to Bitcoin.SE! You ask a serious question and I see you have several good answers already. Good luck!  
> **username_0**: I will revise my question slightly:  Suppose I was not interested in the identity of the person, but I was interested in tracking an ID. In other words, I don't care about Mr. Smith as such, but I want to isolate Mr. Smith's trades, and analyze them seperately from Mr. Jones'. Is that possible?  

---

## 6 answers

### Answer by username_2 on 2018-02-09. Score: 1

Yes & No

You can track a person's transaction only if you know that person's wallet address/es

By the wallet address/es, you can see the transaction.

The incoming transaction can be a buy, or a sale completed, etc.

The outgoing transaction can be a sell, or a purchase, etc.

You can also track a person using all his xpub key to know all the address/es at once.

Buy you cannot track a person just with a name or a single wallet address (if he owns multiple, which at this time, people do).

Hope this answers your question.

> **Comments:**
> **username_0**: Suppose I was not interested in the identity of the person, but I was interested in tracking an ID. In other words, I don't care about Mr. Smith as such, but I want to isolate Mr. Smith's trades, and analyze them seperately from Mr. Jones'. Is that possible?  
> **username_2**: Still the answer would be a yes and no. Yes, if you know his xpub key and he only makes wallet from that xpub key. No, if he have multiple accounts (which is the case in normal scenario)  

---

### Answer by username_1 on 2018-03-10. Score: 0

# Is there information about the buyer and seller in the Blockchain?

Private information, no. Public information, yes. A transaction contains the input addresses (utxo's), public keys, output addresses and, the change address. None of these is stored with any private information on the blockchain and, even the different input or output addresses are not linked in any meaningful way apart from their association in an individual transaction.

Ordinarily, change will be sent back to a different receiving address than the inputs used to fund the transaction, and there is no way to distinguish a change address from any other outputs. Even to determine which of the outputs is the spend output and which is the change address back to the sender (if any) is at best a guess.

Occasionally, a user may be using a wallet configured without the ability to create new addresses. In this case change goes back to one of the input addresses, however, apart from that one address we still have no idea how many additional addresses the user may have with a balance in their wallet, they are not linked.

## Suppose I wanted to track transactions by an individual entity in the Blockchain, say Mr. Smith. Is that possible?

The best you could hope to achieve without guessing is to determine the specific balance of specific addresses but with no way to link those together to understand wallet or user balances. No, that is not possible unless Mr. Smith discloses ownership of all of his addresses and you can find that information to link them.

## I will revise my question slightly: Suppose I was not interested in the identity of the person, but I was interested in tracking an ID. In other words, I don't care about Mr. Smith as such, but I want to isolate Mr. Smith's trades, and analyze them separately from Mr. Jones'. Is that possible?

Given the above, no. There is no way to know which outputs are directed to any particular user, so you cannot then know who is spending. Even if you follow a transaction chain from output, to input, to output, you have no way to know when any BTC has changed hands.


---

### Answer by username_3 on 2018-02-09. Score: 0

Privacy is one of Bitcoin features. Regardless of the infrastructure that wallets follow to protect user privacy.

generating a new address for each transaction is a must.

Even if you have Mr.Smith Address. You will never get full and accurate information about his total balance or his contacts.

What if Mr.Smith address is belonging to an exchange? You are tracking the wrong person.


---

### Answer by username_4 on 2018-02-09. Score: 0

The question is very generic ... as such: No.. There are only addresses, pubkeys and address hashes visible. No names. But (!): assuming you buy s.th. at Amazon with your address, then Amazon knows about the link between address and name (to send the goods to). And we know,that data protection is not their main focus :-)

This is the reason why you want to use addresses only once.


---

### Answer by username_5 on 2018-02-09. Score: 0

Bitcoin means that the people are action pseudonomously. It's almost impossible to find out who is the owner of a random address.

But if you know the pseudonym (if you know that Mr. Smith has address XY), you can track every transaction to/from this address.


---

### Answer by username_6 on 2018-02-09. Score: 0

No, not really. The blockchain tracks which transactions are comprised of outputs of previous transactions. Since a transaction can have multiple inputs (pointing to the outputs of previous transactions) and outputs, each transaction can be paid from multiple people and paid to multiple people. The addresses, themselves, have no association on the blockchain with any person or organization. The blockchain simply doesn't store data on users.

However, if you were able to supplement the blockchain with data on who owns which address, you could to a certain degree of accuracy determine where money is coming from and where it is going. Best privacy practices, however, make this more difficult...even *if* you have data to supplement the blockchain with. This is why we say that Bitcoin is "pseudonymous". You can track how money flows, but not the people/entities behind the movement.


---

