Blockchain attack defense mechanism learning

Short answer questions

Briefly describe the structure and function of the blockchain database.

Explain the role and importance of "miners" in the blockchain.

What is a 51% attack? How does it threaten the security of the blockchain?

In addition to the 51% attack, list and briefly describe two other attacks on the blockchain.

What methods have been proposed to defend against blockchain attacks?

Explain the concept of "transaction creation profile" and its use.

What role does the "profiler data structure" play in the defense mechanism?

How are "profile transactions" generated? How do they help detect malicious events?

If deviations from the "transaction creation profile" are detected, what mitigation measures can be taken?

How does the described defense mechanism apply in the Ethereum environment?

Short answer questions

The blockchain database is a distributed database that stores transaction data in chronological order. It guarantees the security and immutability of data through cryptographic technology, and allows multiple nodes in the network to access and verify transaction information.

Miners are nodes in the blockchain network responsible for verifying transactions and adding new blocks to the blockchain. They compete for the right to record accounts by solving complex mathematical problems and receive corresponding rewards. The existence of miners ensures the decentralization and security of the blockchain.

A 51% attack is when an attacker controls more than half of the computing power in a blockchain network, thereby manipulating transaction data, such as double spending. Attackers can prevent new transactions from being confirmed, or even reverse completed transactions, posing a serious threat to blockchain security.

In addition to 51% attacks, there are Sybil attacks and denial of service attacks. In a Sybil attack, an attacker creates multiple fake nodes to control the network, thereby affecting network consensus. Denial of service attacks send a large amount of junk data to the network, causing network congestion and affecting normal transactions.

A method for detecting blockchain attacks by monitoring transaction patterns is proposed. It uses a "transaction creation profile" to define expected transaction behavior and generates "profile transactions" through a "profiler data structure" to monitor actual transactions.

The "transaction creation profile" defines the rules for expected transaction generation and submission to the blockchain. It can be based on time intervals, blockchain states, or other accessible attributes. By comparing with actual transaction patterns, malicious activities that deviate from expectations can be identified.

The "profiler data structure" is stored in the blockchain and contains executable code for generating "profile transactions" based on the "transaction creation profile". It acts as a monitoring agent, constantly checking whether transaction patterns are as expected.

Profile transactions are generated by executable code in the profiler data structure according to the rules in the transaction creation profile. They are a concrete manifestation of expected transaction behavior, and by monitoring the timing and frequency of their occurrence, it is possible to determine whether there is malicious activity.

If deviations from the transaction creation profile are detected, a variety of mitigation measures can be taken, such as: generating alerts to notify relevant parties, stopping interaction with the blockchain, protecting assets that rely on the blockchain, and conducting deeper investigations on suspicious transactions.

In the Ethereum environment, the profiler data structure can be implemented as a smart contract that contains the logic to check the transaction creation profile and generate the profile transaction. Ethereum's messaging mechanism can be used to trigger the execution of the profiler contract and the generation of the profile transaction.

Thesis Title

Discuss the main security challenges facing blockchain technology and compare and contrast at least three different defense strategies.

Analyze the proposed attack defense mechanism in depth, evaluate its strengths and weaknesses, and explore its applicability on different blockchain platforms.

The design of the transaction creation profile is critical to the effectiveness of the defense mechanism. Propose and demonstrate a design of a "transaction creation profile" for specific application scenarios (e.g., supply chain management, digital identity authentication).

In addition to technical means, what non-technical means can be taken to enhance the security of blockchain? Analyze with actual cases.

As blockchain technology continues to develop, what new security threats may emerge in the future? Explore potential research directions to address these threats.

Glossary of Key Terms

Term Definitions Blockchain database A distributed database that stores data in chronological order, using cryptographic techniques to ensure security and immutability. Miner A node in a blockchain network that is responsible for verifying transactions and adding new blocks to the blockchain. 51% attack An attack in which an attacker controls more than half of the computing power in a blockchain network and can manipulate transaction data. Sybil attack An attack in which an attacker creates multiple fake nodes to control the network. Denial of Service attack An attack that causes network congestion by sending a large amount of junk data. Transaction creation profile defines the rules for expected transaction generation and submission to the blockchain. Profiler data structure A data structure containing executable code stored in the blockchain that is used to generate "profile transactions". Profile transaction Transactions generated based on the "transaction creation profile" to monitor the health of the blockchain. Ethereum is a blockchain-based platform that allows developers to create and deploy smart contracts. Smart contracts are codes stored on the blockchain that are automatically executed when preset conditions are met.