user2229: Fist bitcoins in, First out.
Will this assumption allow individual bitcoin tracking possible?
example,
Addresses A, B and C each has 50 BTC

Transactions, 

  tx1 - A > D - 10 BTC (D - 10 BTC)
  tx2 - B > D - 15 BTC (D - 25 BTC)
  tx3 - C > D - 20 BTC (D - 45 BTC)

  tx4 - D > E - 20 BTC (E - 20 BTC, D - 25 BTC)

  Now,
    D has none of BTC received from A, 5 BTC from B and 20 BTC from C
    E, fist 10 BTC was received from A, next 10 BTC was received from B


user323: This is only true if one does not mix transactions. Otherwise you will have coins that are for example 50% from source A, 10% from B, 40% from C and so forth.

2229: <p>Fist bitcoins in, First out.</p>

<p>Will this assumption allow individual bitcoin tracking possible?</p>

<p>example,</p>

<pre><code>Addresses A, B and C each has 50 BTC

Transactions, 

  tx1 - A &gt; D - 10 BTC (D - 10 BTC)
  tx2 - B &gt; D - 15 BTC (D - 25 BTC)
  tx3 - C &gt; D - 20 BTC (D - 45 BTC)

  tx4 - D &gt; E - 20 BTC (E - 20 BTC, D - 25 BTC)

  Now,
    D has none of BTC received from A, 5 BTC from B and 20 BTC from C
    E, fist 10 BTC was received from A, next 10 BTC was received from B
</code></pre>
 323: <p>This is only true if one does not mix transactions. Otherwise you will have coins that are for example 50% from source A, 10% from B, 40% from C and so forth.</p>
