The Operating Technique Of Transaction Censorship Attack

Source

INTRODUCTION

To begin with, decentralization, which is one of the fundamental values that supports the rolling of transactions in a neutral manner and without requiring permission, is the most paramount in block chain technology. However, as the evolution of the block chain system matures, there are new patterns emerging that depict a threat to this principle. One such vulnerability is the transaction censorship, whereby certain individuals are rewarded in a malicious manner not to incorporate particular transactions into blocks. This may inhibit the participation of the users on the premises of fairness and freedom in the blockchain networks.

Censorship of transactions attacks violates the whole purpose behind trustless infrastructure of blockchain that does not discriminate against any user’s or entities as to who receives information. Instead, it creates a vertical control in what is allegedly a flat structure. These types of attacks involve a situation where a miner, validator, or node processes some transactions and does not include them on the distributed ledger network. Although there are decentralized networks, censorship probably exists in parties that have the power to decide on which transactions to incorporate or not in blocks, the miners and the validators.

High are the repercussions that arise from transaction censorship. Apart from narrowing down the participation of users in the system, it can also escalate to rise in prominence for such.

• HOW TRANSACTION CENSORSHIP ATTACKS WORK

Miners or validators that are in control of the block production process perform transaction censorship attacks. These actors are essential to the operation of most blockchains since they verify and include transactions into the blockchain usually in proof-of-work (PoW) or proof-of-stake (PoS) based consensus mechanisms. In a censorship attack, the attacker selectively makes certain transactions not be included in the next block.

For example, a miner might refuse to include a transaction because it is issued by a certain individual, organization or jurisdiction. This can be done either directly through reading the transaction metadata or wallet addresses and filtering out those transactions/addresses, or indirectly, where an attacker is coerced (e.g., due to legal requirements or economic incentives) into blocking transactions from specific addresses.

The success of such attack depends on the power and control of the attacker over block production. If a sufficiently large portion of the network’s hash rate (or stake) is controlled by an adversary then they can prevent any targeted transactions from being included.

• MINER CENTRALIZATION AND ECONOMIC INCENTIVES:

Source

One of the major requirements for executing transaction censorship attacks is centralization of mining power or stake in a few hands. Ideally, in decentralized networks, the block production should be divided among a large number of independent entities. But often, large mining pools or validator nodes own a skewed portion of the network, which makes them capable of excluding transactions from blocks.

Economic factors are other major enablers for transaction censorship attacks. Miners or validators are often economically motivated to cherry-pick transactions that have high fees associated with them. This sort of economic censorship can discourage low-fee users and prevent them from accessing the system.

Also note that adversaries may be able to cause honest parties to deviate from the protocol by offering economic incentives. For example, an adversary could offer a reward to a miner or validator who censors some specific transaction. This threat seems particularly worrisome in proof-of-stake systems, where validators are chosen proportionally to their ownership of cryptocurrency. In such a case it would be possible for wealthy entities to simply pay validators not to include their competitors’ transactions.

• POLITICAL AND REGULATORY MOTIVATIONS For CENSORSHIP:

Transaction censorship attacks could not only be economically motivated, but also politically or regulatorily. Governments of some jurisdictions may require blockchain operator or miner to censor transactions not complying with its local regulations, such as those relating to illegal activities or blacklisted wallet addresses. This poses a schizophrenic picture for miners.

For examples, the compliance with international economic sanction would lead to transaction censorship against certain countries and/or people captured in a blacklist. In this event, transaction censorship is used as a means to drive through political incubi and allows centralised control take over decentralised network underpinning principle—equal accessibility irrespetive of the participants’ geography and politics.

Furthermore, political motivations for censorship could come from within the blockchain community if there were ever disagreements. Whether it is through forks or governance disputes, you can envision situations where one group would try to censor transactions from another group, leading to a fragmented and less efficient blockchain.

• MITIGATING TRANSACTION CENSORSHIP ATTACKS:

Mitigating such risks requires a multi-faceted approach that considers both the technical and governance structure of blockchain networks. On one hand, we can further decentralize mining or staking power to make it more difficult for attackers to censor transactions through gaining control in block production.

On the other hand, we can utilize cryptographic techniques to anonymize transaction metadata so as to prevent miners or validators from knowing which specific transactions are subject to censorship. For instance, privacy-focused cryptocurrencies like Monero employ advanced cryptographic primitives to obfuscate transaction details, thus rendering impossible for attackers to select transactions for censorship.

Source

CONCLUSION

The integrity and fairness of blockchain networks are seriously threatened by transaction censorship attacks, which enable malicious adversaries to selectively exclude transactions. This not only violates the property of tamper-resistance of the blockchain, but also provides opportunities for economic manipulation, political interference and regulatory control.