Dockeyhunt Long Range Attack

## Introduction

Long Range Attack is a serious threat to blockchain protocols based on the Proof of Stake (PoS) consensus mechanism. Unlike traditional attacks on blockchains, such as the 51% attack in Proof of Work (PoW), a long-range attack exploits vulnerabilities related to the history of the blockchain and the ability to create alternative chains. In this article, we will look at the nature of these attacks, their classification, and offer recommendations for preventing them.

## Nature of long range attack

A long-distance attack occurs when an attacker goes back to the original block and creates a new branch of the blockchain that is partially or completely different from the main chain. The attacker’s goal is to make the branch he created become longer than the main chain and, therefore, overtake it. This is achieved by adding blocks that the attacker keeps secret and then revealing them.

### Classification of long-range attacks

Long range attacks can be divided into three main categories:

1. Simple attacks: The attacker creates an alternative chain starting from the original block and tries to make it longer than the main chain.
2. Backward Corruptions: An attacker alters the history of the blockchain starting from a specific block in the past and creates a new branch that gradually overtakes the main chain.
3. Stake Bleeding: An attacker exploits vulnerabilities in the staking mechanism to create an alternative chain that includes fake transactions.

## Comparison with selfish mining attacks in PoW

In some ways, long-range attacks in PoS protocols are related to selfish mining attacks in PoW protocols. In both cases, the attacker adds blocks that he keeps secret to create an alternative chain. However, unlike PoW, where returning to the original block requires huge computational resources, in PoS this is possible due to the lower cost of creating blocks.

## Recommendations for preventing attacks

To prevent long-range attacks, the following is recommended:

1. Confirmation of transactions: The exchange or recipient must complete the payment only after the transaction has been confirmed by a sufficient number of blocks. This reduces the likelihood of a successful attack, since it will be more difficult for an attacker to create a longer chain.
2. Use of checkpoints: Introducing checkpoints into the blockchain that cannot be changed can prevent the creation of alternative chains.
3. Improving stake mechanisms: Ensuring stricter rules for stake participation and preventing abuse by bad actors.

## Conclusion

Long-range attacks pose a significant threat to blockchain PoS protocols. Understanding the nature of these attacks and their classification allows blockchain developers and users to take measures to prevent them. Following best practices for confirming transactions and using checkpoints can significantly reduce the risk of successful long-range attacks.

## Link

For a more detailed study of long-range attacks in Proof of Stake protocols, we recommend that you read the study at the following link:  Study of long-range attacks in Proof of Stake protocols

Dockeyhunt Long Range Attack


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