<p>Traditional blockchains like Bitcoin and Ethereum use a &quot;first-come, first-served&quot; ordering, with transactions being added to the blockchain in the order they are received. However, this can be manipulated by adversaries through methods like transaction censorship or front-running. Front-running, in particular, is a significant issue in decentralized finance (DeFi) platforms where an adversary can see a profitable transaction, create a copy of that transaction with a higher gas price to have it processed sooner, and thus benefit from the original transaction's market impact.</p>
<p>One proposed solution to this problem is the concept of &quot;batch auctions&quot; or &quot;batch processing&quot;. This involves collecting a set of transactions into a batch and then processing that batch in a single block. However, this method also has its limitations, as you've noted.</p>
<p>Several promising research directions include using cryptography (like verifiable delay functions), or economic game theory (like MEV auctions), or even designing new consensus algorithms to try to address this problem. Some approaches use secret or encrypted transactions that are only revealed and ordered after they are included in a block, but these can come with their own sets of issues and trade-offs.</p>

CC BY-SA 4.0
2023-06-25T09:26:49.597Z
2023-06-25T09:26:49.597Z
tomasantunes
<p>Front running attacks mainly happen because adversaries are able to manipulate the order of the transactions on blockchains.
As many research paper address the problem of fair ordering, I don't find ( so far ) any convincing ordering method that stops rushing adversaries from changing the order of transactions - even batch order fairness has its limits.</p>
<p>The question is : is there a fair ordering technique that always works ?</p>
<p>sources :</p>
<p><a href="https://courses.grainger.illinois.edu/ece598pv/sp2021/lectureslides2021/ECE_598_PV_course_notes13.pdf" rel="nofollow noreferrer">https://courses.grainger.illinois.edu/ece598pv/sp2021/lectureslides2021/ECE_598_PV_course_notes13.pdf</a></p>
<p><a href="https://eprint.iacr.org/2021/1628.pdf" rel="nofollow noreferrer">https://eprint.iacr.org/2021/1628.pdf</a></p>

<ds.algorithms>
Can fair ordering of transactions be achieved in permissionless blockchains?
Namrouch
# Can fair ordering of transactions be achieved in permissionless blockchains?

(Asked by: username_0 on 2022-06-04)

Front running attacks mainly happen because adversaries are able to manipulate the order of the transactions on blockchains.
As many research paper address the problem of fair ordering, I don't find ( so far ) any convincing ordering method that stops rushing adversaries from changing the order of transactions - even batch order fairness has its limits.

The question is : is there a fair ordering technique that always works ?

sources :

<https://courses.grainger.illinois.edu/ece598pv/sp2021/lectureslides2021/ECE_598_PV_course_notes13.pdf>

<https://eprint.iacr.org/2021/1628.pdf>

**Tags:** ds.algorithms


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## 1 answers

### Answer by username_1 on 2023-06-25. Score: -1

Traditional blockchains like Bitcoin and Ethereum use a "first-come, first-served" ordering, with transactions being added to the blockchain in the order they are received. However, this can be manipulated by adversaries through methods like transaction censorship or front-running. Front-running, in particular, is a significant issue in decentralized finance (DeFi) platforms where an adversary can see a profitable transaction, create a copy of that transaction with a higher gas price to have it processed sooner, and thus benefit from the original transaction's market impact.

One proposed solution to this problem is the concept of "batch auctions" or "batch processing". This involves collecting a set of transactions into a batch and then processing that batch in a single block. However, this method also has its limitations, as you've noted.

Several promising research directions include using cryptography (like verifiable delay functions), or economic game theory (like MEV auctions), or even designing new consensus algorithms to try to address this problem. Some approaches use secret or encrypted transactions that are only revealed and ordered after they are included in a block, but these can come with their own sets of issues and trade-offs.


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