<p>I don't see the problem, or what compromises privacy exactly?</p>

<p>Say you have UTXO A1 and B1 of 0.001, (I've never used Coinjoin so i'm just assuming here.)</p>

<p>Now you put both A1 and B1 through Coinjoin, Now you have A2 and B2.</p>

<p>How would combining the outputs of A2 and B2 compromise the privacy of outputs A1 and B1?
You used CoinJoin to break exactly that chain right?</p>

<hr>

<p>Put the balance of the change adresses all individually through coinjoin mixing sessions and then combine the outputs? That way the chain is broken, and due to them being linked only after the chain was broken, privacy isn't compromised?</p>

<hr>

<p>If they're too low of an amount to be send to Coinjoin, i'm afraid it's just dust, and they should be frozen to prevent them from accidently being spent  in the future when tx fees might be lower again.</p>

CC BY-SA 4.0
2019-06-30T20:29:18.470Z
2019-06-30T20:34:32.887Z
2019-06-30T20:34:32.887Z
Jan Janssen
<p>We know that, for security and anonymity, we <a href="https://en.bitcoin.it/wiki/Privacy#Avoiding_address_reuse" rel="nofollow noreferrer">shouldn't reuse addresses</a>. Also, there is the idea of <a href="https://en.bitcoin.it/wiki/Privacy#Change_avoidance" rel="nofollow noreferrer">change avoidance</a> to protect ourselves from any number of <a href="https://en.bitcoin.it/wiki/Privacy#Change_address_detection" rel="nofollow noreferrer">change detection heuristics</a>.</p>

<p>But I find that unspent change addresses ("UTXO's") are often unavoidable. Especially when using other privacy-enhancing techniques, such as equal-output <a href="https://en.bitcoin.it/wiki/Privacy#CoinJoin" rel="nofollow noreferrer">CoinJoins</a>, where you end up with many source addresses.</p>

<p>Is there a good technique to be able to spend these UTXO's without compromising privacy?</p>

<privacy><utxo><change><address-reuse><coinjoin>
Privacy: How should I handle UTXO's?
bitsmack
# Privacy: How should I handle UTXO's?

(Asked by: username_0 on 2019-06-28)

We know that, for security and anonymity, we [shouldn't reuse addresses](https://en.bitcoin.it/wiki/Privacy#Avoiding_address_reuse). Also, there is the idea of [change avoidance](https://en.bitcoin.it/wiki/Privacy#Change_avoidance) to protect ourselves from any number of [change detection heuristics](https://en.bitcoin.it/wiki/Privacy#Change_address_detection).

But I find that unspent change addresses ("UTXO's") are often unavoidable. Especially when using other privacy-enhancing techniques, such as equal-output [CoinJoins](https://en.bitcoin.it/wiki/Privacy#CoinJoin), where you end up with many source addresses.

Is there a good technique to be able to spend these UTXO's without compromising privacy?

**Tags:** privacy, utxo, change, address-reuse, coinjoin


---

## 1 answers

### Answer by username_1 on 2019-06-30. Score: 0

I don't see the problem, or what compromises privacy exactly?

Say you have UTXO A1 and B1 of 0.001, (I've never used Coinjoin so i'm just assuming here.)

Now you put both A1 and B1 through Coinjoin, Now you have A2 and B2.

How would combining the outputs of A2 and B2 compromise the privacy of outputs A1 and B1?
You used CoinJoin to break exactly that chain right?

---

Put the balance of the change adresses all individually through coinjoin mixing sessions and then combine the outputs? That way the chain is broken, and due to them being linked only after the chain was broken, privacy isn't compromised?

---

If they're too low of an amount to be send to Coinjoin, i'm afraid it's just dust, and they should be frozen to prevent them from accidently being spent in the future when tx fees might be lower again.


---

