<p>TTOR (Topological Transaction Ordering) is used by Bitcoin and pre-CTOR Bitcoin Cash. In TTOR, there might be multiple possible ways to sort transactions. The only requirement is, chain of transactions should be sorted by time and the coinbase transaction must be the first.</p>

<p>Let's say there are A, B and C transactions, and assume that there's no coinbase transaction. A and B are usual transactions, but C spends at least one output of B. The possible orderings are:</p>

<pre><code>A B C
B A C
B C A
</code></pre>

<p>Amaclin is right, SegWit didn't change anything related to them.</p>

CC BY-SA 4.0
2018-11-24T09:00:31.887Z
Do you think the CTOR ordering is more efficient then TTOR ordering ? Are there any downsides ?
laizess
CC BY-SA 4.0
2018-11-24T09:15:13.380Z
It was needed, because Graphene, which is an enhanced Compact Blocks, requires any ordering algorithm that had no more than one way to order. CTOR was chosen and analyzed [here](https://blog.vermorel.com/pdf/canonical-tx-ordering-2018-06-12.pdf). A critique can be found [here](https://www.docdroid.net/pvFaNUq/critique-canonical-order.pdf).
MCCCS
CC BY-SA 4.0
2018-11-24T08:39:44.240Z
2018-11-24T08:39:44.240Z
MCCCS
<p>These things are not related to each other at all. So, talking about differences between them is nonsense.</p>

CC BY-SA 4.0
2018-11-24T08:38:06.290Z
2018-11-24T08:38:06.290Z
amaclin
<p>What is the difference between segregated witness (segwit) and canonical transaction ordering (CTOR) ? </p>

<transactions><segregated-witness>
Transaction order in the blockchain
laizess
# Transaction order in the blockchain

(Asked by: username_0 on 2018-11-24)

What is the difference between segregated witness (segwit) and canonical transaction ordering (CTOR) ?

**Tags:** transactions, segregated-witness


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## 2 answers

### Answer by username_1 on 2018-11-24. Score: 3

TTOR (Topological Transaction Ordering) is used by Bitcoin and pre-CTOR Bitcoin Cash. In TTOR, there might be multiple possible ways to sort transactions. The only requirement is, chain of transactions should be sorted by time and the coinbase transaction must be the first.

Let's say there are A, B and C transactions, and assume that there's no coinbase transaction. A and B are usual transactions, but C spends at least one output of B. The possible orderings are:

```
A B C
B A C
B C A

```

username_2 is right, SegWit didn't change anything related to them.

> **Comments:**
> **username_0**: Do you think the CTOR ordering is more efficient then TTOR ordering ? Are there any downsides ?  
> **username_1**: It was needed, because Graphene, which is an enhanced Compact Blocks, requires any ordering algorithm that had no more than one way to order. CTOR was chosen and analyzed [here](https://blog.vermorel.com/pdf/canonical-tx-ordering-2018-06-12.pdf). A critique can be found [here](https://www.docdroid.net/pvFaNUq/critique-canonical-order.pdf).  

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### Answer by username_2 on 2018-11-24. Score: 0

These things are not related to each other at all. So, talking about differences between them is nonsense.


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