IELTS Reading: Blockchain Và An Ninh Số – Đề Thi Mẫu Có Đáp Án Chi Tiết

Mở bài

Công nghệ blockchain đang dần trở thành một trong những chủ đề phổ biến trong các đề thi IELTS Reading, đặc biệt là trong những năm gần đây khi vấn đề an ninh số ngày càng trở nên cấp thiết. Chủ đề “How Blockchain Is Improving Digital Security” không chỉ xuất hiện trong bối cảnh công nghệ thông tin mà còn liên quan đến nhiều lĩnh vực như tài chính, y tế, và quản lý dữ liệu cá nhân.

Theo thống kê từ Cambridge IELTS và British Council, các đề tài liên quan đến công nghệ và bảo mật thông tin chiếm khoảng 15-20% trong các bài thi IELTS Reading. Việc nắm vững chủ đề này không chỉ giúp bạn tự tin hơn khi gặp phải trong phòng thi mà còn mở rộng vốn từ vựng học thuật quan trọng.

Trong bài viết này, bạn sẽ được trải nghiệm một đề thi IELTS Reading hoàn chỉnh với ba passages có độ khó tăng dần từ Easy đến Hard. Mỗi passage đi kèm với các dạng câu hỏi đa dạng giống như thi thật, đáp án chi tiết kèm giải thích cụ thể, và bảng từ vựng thiết yếu giúp bạn nâng cao khả năng đọc hiểu. Đề thi này phù hợp cho học viên có trình độ từ band 5.0 trở lên, đặc biệt hữu ích cho những ai đang hướng tới mục tiêu band 6.5-7.5.

1. Hướng Dẫn Làm Bài IELTS Reading

Tổng Quan Về IELTS Reading Test

IELTS Reading Test kéo dài 60 phút và bao gồm 3 passages với tổng cộng 40 câu hỏi. Mỗi câu trả lời đúng được tính là 1 điểm, không có điểm âm cho câu trả lời sai. Độ khó của các passages tăng dần, với Passage 1 thường dễ nhất và Passage 3 khó nhất.

Phân bổ thời gian khuyến nghị:

• Passage 1: 15-17 phút (13 câu hỏi)
• Passage 2: 18-20 phút (13 câu hỏi)
• Passage 3: 23-25 phút (14 câu hỏi)

Lưu ý rằng đây chỉ là gợi ý, bạn hoàn toàn có thể điều chỉnh tùy theo khả năng cá nhân. Điều quan trọng là phải dành thời gian để chuyển đáp án lên phiếu trả lời (Answer Sheet) một cách cẩn thận.

Các Dạng Câu Hỏi Trong Đề Này

Đề thi mẫu này bao gồm 7 dạng câu hỏi phổ biến trong IELTS Reading:

1. Multiple Choice – Câu hỏi trắc nghiệm
2. True/False/Not Given – Xác định thông tin đúng/sai/không được đề cập
3. Matching Information – Ghép thông tin với đoạn văn
4. Yes/No/Not Given – Xác định ý kiến tác giả
5. Matching Headings – Chọn tiêu đề phù hợp cho đoạn văn
6. Summary Completion – Hoàn thành đoạn tóm tắt
7. Sentence Completion – Hoàn thành câu

2. IELTS Reading Practice Test

PASSAGE 1 – The Foundation of Blockchain Security

Độ khó: Easy (Band 5.0-6.5)

Thời gian đề xuất: 15-17 phút

In recent years, digital security has become one of the most pressing concerns for individuals, businesses, and governments worldwide. Traditional methods of protecting data, such as centralized databases and password systems, have proven vulnerable to increasingly sophisticated cyber attacks. This is where blockchain technology enters the picture, offering a fundamentally different approach to securing digital information.

Blockchain is essentially a distributed ledger – a type of database that is shared across multiple computers or nodes in a network. Unlike traditional databases that store information in one central location, blockchain spreads data across many locations simultaneously. Each block in the chain contains a number of transactions, and every time a new transaction occurs on the blockchain, a record of that transaction is added to every participant’s ledger. This decentralized nature is the first key to understanding how blockchain improves security.

The concept was first introduced in 2008 by an anonymous person or group known as Satoshi Nakamoto as the underlying technology for Bitcoin, the first cryptocurrency. However, experts quickly realized that the technology had applications far beyond digital currency. Today, blockchain is being explored and implemented in sectors ranging from healthcare to supply chain management, from voting systems to identity verification.

What makes blockchain particularly secure is its use of cryptographic hashing. Each block contains three essential elements: the data itself, a unique code called a hash, and the hash of the previous block. Think of a hash as a digital fingerprint – it’s unique to each block and its contents. If someone attempts to alter the information in a block, the hash changes immediately. Since each block contains the previous block’s hash, any tampering becomes immediately apparent throughout the entire chain. This creates an immutable record – once data is recorded, it becomes extremely difficult to change it retrospectively.

Another crucial security feature is the consensus mechanism. Before a new block can be added to the chain, the majority of nodes in the network must agree that the transaction is valid. This process, known as consensus, prevents fraudulent transactions from being added to the blockchain. The most common consensus mechanism is called Proof of Work, which requires significant computational power to add new blocks, making it economically unfeasible for hackers to manipulate the system.

Transparency is another fundamental characteristic that enhances security. In most blockchain systems, every transaction is visible to all participants in the network. While the identities of the users may be encrypted, the transaction details are open for anyone to verify. This level of transparency makes it nearly impossible for someone to hide fraudulent activities. If someone tries to cheat the system, it will be visible to everyone, and the network will reject the invalid transaction.

The peer-to-peer network structure of blockchain also eliminates single points of failure. In traditional centralized systems, if a hacker gains access to the central server, they can potentially access or corrupt all the data. With blockchain, there is no single point of attack. An attacker would need to simultaneously compromise more than half of the computers in the network to successfully manipulate the blockchain – a task that becomes exponentially more difficult as the network grows larger.

Real-world applications are already demonstrating blockchain’s security benefits. For instance, Estonia, a small European country, has implemented blockchain technology in its e-governance systems to protect citizen data and government records. The system has successfully prevented multiple cyber attacks, including sophisticated attempts by foreign actors. Similarly, major companies like IBM and Maersk have developed blockchain-based platforms for tracking shipping containers globally, significantly reducing fraud and errors in international trade.

However, it’s important to note that blockchain is not a perfect solution. The technology is still relatively new, and challenges remain. Scalability – the ability to handle large numbers of transactions quickly – is one significant limitation. The energy consumption required for some blockchain networks, particularly those using Proof of Work, has raised environmental concerns. Additionally, while the blockchain itself may be secure, the points where users interact with it, such as digital wallets and exchanges, can still be vulnerable to hacking.

Despite these challenges, blockchain represents a paradigm shift in how we think about digital security. By distributing data, using cryptographic protection, requiring network consensus, and maintaining transparency, blockchain creates multiple layers of security that make unauthorized access or tampering extremely difficult. As the technology continues to evolve and mature, it is likely to play an increasingly important role in protecting our digital lives.

Questions 1-13

Questions 1-5: Multiple Choice

Choose the correct letter, A, B, C, or D.

1. According to the passage, what is the main weakness of traditional data protection methods?

   • A) They are too expensive to maintain
   • B) They rely on centralized storage systems
   • C) They require too much technical knowledge
   • D) They are difficult to implement

2. What does the term “hash” refer to in blockchain technology?

   • A) A type of encryption password
   • B) A unique digital identifier for each block
   • C) A computer program that verifies transactions
   • D) A method of storing cryptocurrency

3. The consensus mechanism in blockchain is primarily designed to:

   • A) Speed up transaction processing
   • B) Reduce energy consumption
   • C) Prevent fraudulent transactions
   • D) Increase network transparency

4. According to the passage, what makes blockchain’s peer-to-peer structure secure?

   • A) It requires expensive hardware
   • B) It uses advanced passwords
   • C) It has no single point of failure
   • D) It limits the number of users

5. What is mentioned as a challenge for blockchain technology?

   • A) Lack of transparency
   • B) Too much centralization
   • C) Scalability issues
   • D) Insufficient cryptographic protection

Questions 6-9: True/False/Not Given

Write TRUE if the statement agrees with the information, FALSE if it contradicts, or NOT GIVEN if there is no information.

6. Satoshi Nakamoto’s real identity has been confirmed by blockchain experts.

7. Every transaction on a blockchain is visible to all network participants.

8. Blockchain technology was initially developed for healthcare applications.

9. Estonia has successfully used blockchain to protect against cyber attacks.

Questions 10-13: Sentence Completion

Complete the sentences below using NO MORE THAN TWO WORDS from the passage.

10. In a blockchain, each block contains data, its own hash, and the __ of the previous block.

11. The __ of blockchain means that once information is recorded, it cannot be easily changed.

12. To manipulate a blockchain successfully, an attacker would need to compromise more than __ of the network’s computers.

13. Digital wallets and exchanges are examples of __ where users interact with blockchain systems.

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PASSAGE 2 – Blockchain Applications in Modern Security Systems

Độ khó: Medium (Band 6.0-7.5)

Thời gian đề xuất: 18-20 phút

The theoretical advantages of blockchain technology in enhancing digital security are becoming increasingly evident through practical implementations across various sectors. As organizations grapple with the escalating sophistication of cyber threats, blockchain’s unique architectural features are being leveraged to address vulnerabilities that have plagued conventional security frameworks for decades. This shift represents not merely an incremental improvement but a fundamental reconceptualization of how data integrity, authentication, and access control can be achieved in the digital realm.

A. Identity Management and Authentication

One of the most promising applications of blockchain lies in revolutionizing identity management systems. Traditional identity verification relies heavily on centralized authorities – government agencies, banks, or tech companies – that maintain databases of personal information. These centralized repositories present attractive targets for cybercriminals, as evidenced by numerous high-profile data breaches affecting millions of users. The Equifax breach of 2017, which exposed sensitive information of 147 million people, exemplifies the catastrophic consequences of centralized identity storage.

Blockchain-based self-sovereign identity (SSI) systems offer a radical alternative. In an SSI framework, individuals maintain control over their personal information, storing cryptographic proofs of their identity on a blockchain rather than entrusting it to centralized entities. When verification is required, users can selectively disclose only the necessary information without revealing their entire identity profile. For instance, when purchasing age-restricted items, a person could prove they are over 18 without disclosing their exact birthdate, address, or other personal details. Như đã thấy trong những thách thức về challenges of ensuring digital privacy, việc kiểm soát dữ liệu cá nhân đang trở nên cấp thiết hơn bao giờ hết.

Several countries are pioneering SSI implementations. Switzerland has launched a blockchain-based digital identity project that allows citizens to control their personal data while still meeting regulatory requirements. Similarly, the city of Zug has implemented a blockchain identity system that residents use to access municipal services. These initiatives demonstrate that decentralized identity is not merely theoretical but practically viable.

B. Supply Chain Security and Authentication

The complexity of global supply chains creates numerous security vulnerabilities, from counterfeit products to unauthorized modifications and inadequate tracking. Blockchain technology addresses these challenges by creating an immutable record of a product’s journey from manufacturer to end consumer. Each participant in the supply chain – manufacturer, distributor, retailer – adds verified information to the blockchain, creating a transparent and tamper-proof history.

The pharmaceutical industry has been particularly aggressive in adopting blockchain for supply chain security. Counterfeit medications represent a significant global health threat, with the World Health Organization estimating that one in ten medical products in developing countries is substandard or falsified. Blockchain-based systems enable patients and healthcare providers to verify the authenticity and proper handling of medications by scanning a code that links to the product’s complete blockchain record. Companies like Pfizer and Genentech are collaborating on the MediLedger Project, a blockchain network designed to track prescription medications and prevent counterfeits from entering the legitimate supply chain.

The diamond industry provides another compelling example. The provenance of diamonds has long been a concern, with “blood diamonds” from conflict zones entering the legitimate market despite international regulations. Everledger, a blockchain platform, has tracked millions of diamonds, recording their unique characteristics and ownership history on a blockchain. This creates a verifiable certificate of authenticity and ethical sourcing that follows the diamond throughout its lifecycle, making it nearly impossible to launder stones of questionable origin.

C. Smart Contracts and Automated Security

Smart contracts – self-executing agreements with terms directly written into code – represent a significant evolution in how security protocols can be automated. Unlike traditional contracts that require intermediaries to enforce, smart contracts automatically execute when predetermined conditions are met. This automation eliminates opportunities for human error or malicious manipulation during contract execution.

In insurance, smart contracts are transforming claims processing. Traditional insurance claims are time-consuming, requiring documentation verification, assessment, and approval – all potential points for fraud or error. Blockchain-based insurance platforms can automatically verify claims and trigger payments when conditions are met. For example, flight delay insurance can be programmed to automatically compensate passengers when flight tracking data confirms a qualifying delay, eliminating the need for claims forms, documentation, and manual processing.

The implications for cybersecurity insurance are particularly significant. Smart contracts can enforce security standards by making policy payments contingent on verified compliance with security protocols. Organizations could prove their adherence to security best practices through blockchain-recorded evidence, potentially reducing premiums while providing insurers with greater certainty about risk exposure.

D. Securing Internet of Things (IoT) Networks

The proliferation of Internet of Things devices – from smart home appliances to industrial sensors – has created an expansive attack surface for cyber threats. Traditional security models struggle with IoT networks because they typically rely on centralized authentication servers that can become bottlenecks or single points of failure. Moreover, many IoT devices have limited computational resources, making it difficult to implement robust security measures.

Blockchain offers a distributed security model particularly suited to IoT environments. Rather than authenticating through a central server, IoT devices can verify each other’s identity and authorize communications through blockchain-based protocols. This device-to-device authentication eliminates centralized vulnerabilities while distributing the computational burden across the network. Research conducted at the Massachusetts Institute of Technology has demonstrated that blockchain-based IoT security systems can reduce unauthorized access attempts by over 90% compared to traditional centralized approaches.

However, implementing blockchain in IoT networks requires addressing the technology’s inherent limitations, particularly regarding transaction speed and energy consumption. Researchers are developing lightweight blockchain protocols specifically designed for resource-constrained IoT devices, utilizing modified consensus mechanisms that require less computational power while maintaining security guarantees.

Questions 14-26

Questions 14-18: Yes/No/Not Given

Write YES if the statement agrees with the writer’s claims, NO if it contradicts, or NOT GIVEN if it is impossible to say.

14. The Equifax breach demonstrated the risks of storing personal information in centralized databases.

15. Self-sovereign identity systems eliminate all privacy concerns in digital transactions.

16. Switzerland’s blockchain identity project has been adopted by all European Union countries.

17. The World Health Organization has confirmed that counterfeit medications are more prevalent in developing countries.

18. Smart contracts completely eliminate the need for lawyers in business transactions.

Questions 19-22: Matching Headings

Match each paragraph (A-D) with the correct heading from the list below.

List of Headings:

• i. Addressing vulnerabilities in connected devices
• ii. Financial applications of distributed ledgers
• iii. Reforming personal data control systems
• iv. Automated enforcement of agreements
• v. Protecting product authenticity and traceability
• vi. Government regulation of blockchain technology
• vii. Environmental concerns about new technologies

19. Section A
20. Section B
21. Section C
22. Section D

Questions 23-26: Summary Completion

Complete the summary below using words from the box.

Word Box:
verification, counterfeit, authentication, automatically, manually, transparency, privacy, centralized, distributed, expensive

Blockchain technology is transforming supply chain security by creating records that cannot be altered. In the pharmaceutical sector, this helps combat (23) __ medications that pose serious health risks. The diamond industry uses blockchain to ensure ethical sourcing and prevent illegitimate stones from entering the market. Smart contracts offer another security advantage by executing (24) __ when specific conditions are fulfilled, reducing opportunities for fraud. For Internet of Things networks, blockchain provides a (25) __ security model where devices can verify each other without relying on a single server. This approach is particularly valuable because it eliminates (26) __ vulnerabilities that hackers often exploit.

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PASSAGE 3 – Cryptographic Foundations and Future Challenges of Blockchain Security

Độ khó: Hard (Band 7.0-9.0)

Thời gian đề xuất: 23-25 phút

While the practical applications of blockchain technology in enhancing digital security have garnered considerable attention, a comprehensive understanding of its security properties necessitates an examination of the underlying cryptographic primitives and the theoretical limitations that constrain its deployment. The security assurances provided by blockchain systems are predicated on sophisticated mathematical constructs, the robustness of which determines whether the technology can fulfill its promise of creating a fundamentally more secure digital infrastructure. Moreover, as blockchain technology matures and adoption accelerates, emerging threats and architectural challenges are revealing that the path toward ubiquitous blockchain-based security is considerably more complex than early proponents anticipated.

The Cryptographic Architecture of Blockchain Security

The security infrastructure of blockchain rests primarily on two cryptographic pillars: hash functions and public-key cryptography, often referred to as asymmetric cryptography. Hash functions, particularly SHA-256 (Secure Hash Algorithm 256-bit) employed by Bitcoin and many other blockchain implementations, serve as the foundation for blockchain’s immutability. These functions possess several critical properties: they are deterministic (identical inputs always produce identical outputs), they generate fixed-size outputs regardless of input size, they are computationally efficient in one direction but computationally infeasible to reverse, and even minute changes to input data produce drastically different outputs – a characteristic known as the avalanche effect.

This last property is fundamental to blockchain’s tamper-evidence mechanism. When a malicious actor attempts to alter historical data within a blockchain, the modification changes the block’s hash, which consequently invalidates all subsequent blocks that reference it. The attacker would need to recalculate not only the compromised block’s hash but also the hashes of all subsequent blocks – a task that becomes exponentially more difficult as the chain lengthens and as more computational resources across the network are committed to extending the chain with legitimate blocks. The security model thus derives from a race condition: as long as honest participants collectively control more computational power than potential attackers, the attacker cannot sustain a fraudulent chain that will be accepted by the network.

Public-key cryptography provides the second essential security component, enabling authentication and non-repudiation without requiring parties to share secret information. Each blockchain participant possesses a key pair: a private key kept secret and a public key distributed freely. When initiating a transaction, users create a digital signature using their private key – a cryptographic proof that only the holder of that specific private key could have generated. Other network participants can verify the signature’s authenticity using the sender’s public key without ever accessing the private key itself. This asymmetric arrangement solves a fundamental problem in digital security: how to verify identity and authorize actions across an untrusted network without exposing credentials that could be stolen and misused. Tương tự như cách how blockchain technology is revolutionizing digital identity management, công nghệ này đang tạo ra những thay đổi căn bản trong cách chúng ta xác thực danh tính số.

The combination of these cryptographic mechanisms creates what cryptographers describe as computational security – security based not on mathematical impossibility but on computational impracticality. Given infinite time and resources, an attacker could theoretically break these protections through brute force methods, trying every possible combination until finding one that works. However, with sufficiently large key sizes, the time required exceeds not just human lifespans but the projected lifespan of the universe itself. A 256-bit key, for instance, would require testing 2^256 possible combinations – a number so astronomically large that even if every computer on Earth worked on the problem for millions of years, the probability of success would remain negligible.

Minh họa cấu trúc mật mã học của blockchain với hash functions và public-key cryptography

Consensus Mechanisms and Their Security Implications

The security of blockchain systems extends beyond cryptography to encompass consensus protocols – the mechanisms by which distributed networks agree on the state of the ledger without central coordination. The original and most well-known consensus mechanism, Proof of Work (PoW), achieves security through economic incentives and resource expenditure. Participants called miners compete to solve computationally intensive puzzles, with the winner earning the right to add the next block and receiving a cryptocurrency reward. This system’s security derives from making attacks economically prohibitive: to successfully manipulate the blockchain, an attacker would need to control over 50% of the network’s computational power – a 51% attack – and sustain that control while racing to create a longer fraudulent chain than the honest network produces.

While PoW has proven remarkably resilient in large networks like Bitcoin, which now represents computational power exceeding that of the world’s most powerful supercomputers combined by orders of magnitude, it suffers from significant limitations. The energy consumption required to maintain PoW security has become environmentally unsustainable, with some estimates suggesting that major PoW blockchains consume electricity comparable to small nations. Additionally, the oligopolistic concentration of mining power in regions with cheap electricity and among entities with specialized hardware creates potential security vulnerabilities, as the network’s security assumption – that no single entity can control a majority of computational resources – becomes increasingly tenuous.

Alternative consensus mechanisms have emerged to address these limitations, each presenting distinct security trade-offs. Proof of Stake (PoS) replaces computational work with economic stake: participants’ influence over consensus is proportional to their holdings of the cryptocurrency itself. This dramatically reduces energy consumption while theoretically maintaining security through economic disincentives – an attacker would need to acquire a majority of the cryptocurrency, an investment that would be devalued by any successful attack. However, PoS introduces new attack vectors, including nothing-at-stake problems where validators have no cost to vote for multiple competing chain histories, potentially enabling certain types of attacks that are impossible under PoW.

Delegated Byzantine Fault Tolerance (dBFT), Practical Byzantine Fault Tolerance (PBFT), and various hybrid approaches attempt to balance security, performance, and decentralization, but each involves compromises. Higher-performance systems typically achieve their speed by restricting participation in consensus to a smaller set of validators, thereby reintroducing elements of centralization and creating potential single points of compromise. The fundamental tension – often characterized as the blockchain trilemma – suggests that optimizing for any two of security, scalability, and decentralization necessarily compromises the third.

Emerging Threats and Adaptive Responses

As blockchain technology matures and adversaries develop more sophisticated attack strategies, new categories of threats are emerging that challenge the security assumptions underlying current implementations. Quantum computing represents perhaps the most existential long-term threat to blockchain security. The cryptographic algorithms securing contemporary blockchains – particularly public-key cryptography – are vulnerable to attacks by sufficiently powerful quantum computers. Shor’s algorithm, a quantum algorithm, could theoretically break widely used encryption schemes in polynomial time, a task that would require exponential time on classical computers.

While current quantum computers remain too primitive to threaten blockchain cryptography, the timeline for achieving quantum supremacy in cryptographically relevant operations is uncertain and potentially shorter than previously anticipated. This has spurred research into post-quantum cryptography – cryptographic algorithms believed to be resistant to quantum attacks. Organizations like the National Institute of Standards and Technology (NIST) are actively working to standardize quantum-resistant algorithms, and forward-thinking blockchain projects are beginning to implement quantum-resistant signatures, even though the immediate threat remains theoretical. The challenge lies in transitioning existing blockchains with billions of dollars in value to quantum-resistant cryptography without creating vulnerabilities during the migration process. Trong bối cảnh của blockchain in global healthcare systems, việc đảm bảo an ninh dữ liệu trước các mối đe dọa tương lai này đặc biệt quan trọng.

Smart contract vulnerabilities constitute another significant and more immediate security challenge. While blockchain itself may be secure, the code executing on top of it – particularly Ethereum’s Turing-complete smart contracts – can contain bugs or logical flaws that attackers exploit. The infamous DAO attack of 2016, which resulted in the theft of approximately $60 million in cryptocurrency, exemplified how programming errors in smart contracts can undermine the security of blockchain-based systems. Unlike traditional software where patches can be deployed to fix vulnerabilities, the immutability that makes blockchain secure also makes fixing flawed smart contracts extraordinarily difficult, sometimes requiring controversial hard forks that split the blockchain into competing versions.

The development of formal verification techniques – mathematical proofs of software correctness – represents a promising avenue for addressing smart contract security. Several blockchain platforms now support formal verification tools that can mathematically prove a smart contract behaves according to its specification, eliminating entire categories of vulnerabilities. However, formal verification requires significant expertise and development time, creating practical barriers to widespread adoption, particularly in the fast-moving cryptocurrency ecosystem where time-to-market often takes precedence over security rigor.

Privacy-Security Tensions and Regulatory Challenges

Blockchain’s transparency, while enhancing security through auditability, creates inherent tensions with privacy requirements. In public blockchains, transaction histories are permanently visible to all participants, enabling sophisticated transaction graph analysis that can potentially de-anonymize users by correlating patterns of activity. This has led to the development of privacy-preserving blockchain technologies employing advanced cryptographic techniques such as zero-knowledge proofs, which allow verification of information without revealing the information itself, and ring signatures, which obscure the true signer among a group of possible signers.

These privacy enhancements, while technologically sophisticated, introduce additional security considerations and face potential regulatory resistance. Authorities concerned about money laundering, terrorist financing, and tax evasion view complete transaction privacy as problematic, creating tension between privacy-enhancing technologies and regulatory compliance. Blockchain systems must increasingly navigate this complex landscape, implementing sufficient privacy to protect legitimate users while maintaining adequate transparency to satisfy regulatory requirements – a balance that may ultimately require different blockchain architectures for different use cases rather than a single universal solution.

The intersection of blockchain security with regulatory frameworks presents additional challenges. As exemplified by discussions around how is blockchain technology impacting financial transparency, regulators worldwide are grappling with how to oversee blockchain-based systems that fundamentally challenge traditional regulatory models premised on identifiable intermediaries. The European Union’s General Data Protection Regulation (GDPR), which grants individuals the “right to be forgotten,” conflicts with blockchain’s immutability. This regulatory-technical tension has no simple resolution and may require either regulatory accommodation of blockchain’s unique characteristics or architectural modifications to blockchain systems that compromise some of their fundamental properties.

Conclusion: A Nuanced Security Proposition

The security advantages blockchain technology offers for digital systems are substantial but nuanced. In scenarios where decentralization, transparency, and immutability align with security objectives, blockchain provides demonstrable improvements over traditional architectures. However, characterizing blockchain as a universal security solution oversimplifies a complex technological landscape. The security properties of any particular blockchain implementation depend critically on design choices regarding consensus mechanisms, network participation models, cryptographic algorithms, and the specific application context. As the technology continues to evolve and face increasingly sophisticated threats, maintaining blockchain’s security advantages will require ongoing research, careful engineering, and realistic assessment of both capabilities and limitations. The path forward involves not replacing all existing security infrastructure with blockchain but thoughtfully identifying contexts where its unique properties provide genuine advantages and implementing it with full awareness of the trade-offs involved.

Questions 27-40

Questions 27-31: Multiple Choice

Choose the correct letter, A, B, C, or D.

27. According to the passage, the avalanche effect in hash functions refers to:

    • A) The exponential growth of blockchain networks
    • B) How small input changes produce drastically different outputs
    • C) The cascading failure of security systems
    • D) The rapid spread of malware in digital systems

28. What is described as the main limitation of Proof of Work consensus mechanisms?

    • A) Insufficient security for large transactions
    • B) Vulnerability to quantum computing attacks
    • C) Environmental unsustainability due to energy consumption
    • D) Inability to prevent all types of cyber attacks

29. The blockchain trilemma suggests that:

    • A) All blockchains will eventually fail
    • B) Three types of attacks threaten blockchain security
    • C) Optimizing two of security, scalability, and decentralization compromises the third
    • D) Blockchain requires three different types of encryption

30. According to the passage, quantum computing threatens blockchain because:

    • A) It can reverse hash functions easily
    • B) It could break public-key cryptography algorithms
    • C) It requires too much energy to operate
    • D) It eliminates the need for consensus mechanisms

31. The DAO attack of 2016 demonstrated that:

    • A) Blockchain itself is fundamentally insecure
    • B) Smart contract code can contain exploitable vulnerabilities
    • C) Quantum computers can break encryption
    • D) Privacy features are ineffective

Questions 32-36: Matching Features

Match each security concept (32-36) with the correct description (A-H).

Security Concepts:
32. Computational security
33. 51% attack
34. Nothing-at-stake problem
35. Zero-knowledge proofs
36. Formal verification

Descriptions:

• A) A vulnerability specific to Proof of Stake systems
• B) Mathematical proof that software behaves correctly
• C) Security based on computational impracticality rather than impossibility
• D) Method to verify information without revealing it
• E) Attack requiring control of majority network power
• F) Encryption that cannot be broken
• G) Method of hiding transaction values
• H) Process of creating new cryptocurrency

Questions 37-40: Short-answer Questions

Answer the questions below using NO MORE THAN THREE WORDS AND/OR A NUMBER from the passage.

37. What cryptographic algorithm is mentioned as being capable of breaking current encryption schemes using quantum computers?

38. Which regulation is mentioned as conflicting with blockchain’s immutability due to privacy rights?

39. What mathematical construct provides authentication without requiring parties to share secret information?

40. According to the passage, what would the time required to break 256-bit encryption through brute force exceed?

Hình ảnh thể hiện các thách thức của công nghệ blockchain với quantum computing và smart contract vulnerabilities

3. Answer Keys – Đáp Án

PASSAGE 1: Questions 1-13

1. B
2. B
3. C
4. C
5. C
6. NOT GIVEN
7. TRUE
8. FALSE
9. TRUE
10. hash
11. immutable record
12. half
13. points/interfaces

PASSAGE 2: Questions 14-26

14. YES
15. NOT GIVEN
16. NOT GIVEN
17. YES
18. NO
19. iii
20. v
21. iv
22. i
23. counterfeit
24. automatically
25. distributed
26. centralized

PASSAGE 3: Questions 27-40

27. B
28. C
29. C
30. B
31. B
32. C
33. E
34. A
35. D
36. B
37. Shor’s algorithm
38. GDPR / General Data Protection Regulation
39. public-key cryptography / asymmetric cryptography
40. universe’s lifespan / universe lifespan

4. Giải Thích Đáp Án Chi Tiết

Passage 1 – Giải Thích

Câu 1: B

• Dạng câu hỏi: Multiple Choice
• Từ khóa: main weakness, traditional data protection methods
• Vị trí trong bài: Đoạn 1, dòng 2-4
• Giải thích: Bài đọc nói rõ “Traditional methods of protecting data, such as centralized databases and password systems, have proven vulnerable”. Điều này được paraphrase thành “rely on centralized storage systems” trong đáp án B. Các phương án khác không được đề cập như điểm yếu chính.

Câu 2: B

• Dạng câu hỏi: Multiple Choice
• Từ khóa: hash, blockchain technology
• Vị trí trong bài: Đoạn 4, dòng 3-4
• Giải thích: Bài viết giải thích “Think of a hash as a digital fingerprint – it’s unique to each block and its contents”. Đây chính xác là “unique digital identifier” trong đáp án B.

Câu 3: C

• Dạng câu hỏi: Multiple Choice
• Từ khóa: consensus mechanism, primarily designed
• Vị trí trong bài: Đoạn 5, dòng 2-3
• Giải thích: Đoạn văn nói rõ “This process, known as consensus, prevents fraudulent transactions from being added to the blockchain”, trực tiếp tương ứng với đáp án C.

Câu 4: C

• Dạng câu hỏi: Multiple Choice
• Từ khóa: peer-to-peer structure, secure
• Vị trí trong bài: Đoạn 7, dòng 1-3
• Giải thích: Bài viết khẳng định “The peer-to-peer network structure of blockchain also eliminates single points of failure”, được paraphrase thành “has no single point of failure” trong đáp án C.

Câu 5: C

• Dạng câu hỏi: Multiple Choice
• Từ khóa: challenge, blockchain technology
• Vị trí trong bài: Đoạn 9, dòng 2-3
• Giải thích: Đoạn cuối đề cập “Scalability – the ability to handle large numbers of transactions quickly – is one significant limitation”. Đây chính là “scalability issues” trong đáp án C.

Câu 6: NOT GIVEN

• Dạng câu hỏi: True/False/Not Given
• Từ khóa: Satoshi Nakamoto, real identity, confirmed
• Vị trí trong bài: Đoạn 3
• Giải thích: Bài viết chỉ nói Satoshi Nakamoto là “anonymous person or group” nhưng không đề cập đến việc danh tính có được xác nhận hay không.

Câu 7: TRUE

• Dạng câu hỏi: True/False/Not Given
• Từ khóa: every transaction, visible, all network participants
• Vị trí trong bài: Đoạn 6, dòng 1-2
• Giải thích: Bài viết khẳng định “In most blockchain systems, every transaction is visible to all participants in the network”, khớp hoàn toàn với câu hỏi.

Câu 8: FALSE

• Dạng câu hỏi: True/False/Not Given
• Từ khóa: Blockchain, initially developed, healthcare
• Vị trí trong bài: Đoạn 3
• Giải thích: Bài đọc nói rõ blockchain được giới thiệu lần đầu như “underlying technology for Bitcoin, the first cryptocurrency”, không phải cho healthcare. Do đó câu này SAI.

Câu 9: TRUE

• Dạng câu hỏi: True/False/Not Given
• Từ khóa: Estonia, blockchain, cyber attacks
• Vị trí trong bài: Đoạn 8, dòng 2-4
• Giải thích: Bài viết khẳng định “The system has successfully prevented multiple cyber attacks, including sophisticated attempts by foreign actors”, trùng khớp với câu hỏi.

Câu 10: hash

• Dạng câu hỏi: Sentence Completion
• Từ khóa: each block contains, previous block
• Vị trí trong bài: Đoạn 4, dòng 2-3
• Giải thích: “Each block contains three essential elements: the data itself, a unique code called a hash, and the hash of the previous block”.

Câu 11: immutable record

• Dạng câu hỏi: Sentence Completion
• Từ khóa: means information recorded, cannot be easily changed
• Vị trí trong bài: Đoạn 4, dòng 6-7
• Giải thích: “This creates an immutable record – once data is recorded, it becomes extremely difficult to change it retrospectively”.

Câu 12: half

• Dạng câu hỏi: Sentence Completion
• Từ khóa: attacker, compromise, network’s computers
• Vị trí trong bài: Đoạn 7, dòng 3-5
• Giải thích: “An attacker would need to simultaneously compromise more than half of the computers in the network”.

Câu 13: points/interfaces

• Dạng câu hỏi: Sentence Completion
• Từ khóa: digital wallets, exchanges, users interact
• Vị trí trong bài: Đoạn 9, dòng 4-5
• Giải thích: “The points where users interact with it, such as digital wallets and exchanges, can still be vulnerable”. Có thể dùng “points” hoặc từ tương đương.

Passage 2 – Giải Thích

Câu 14: YES

• Dạng câu hỏi: Yes/No/Not Given
• Từ khóa: Equifax breach, risks, centralized databases
• Vị trí trong bài: Section A, dòng 3-5
• Giải thích: Bài viết đưa ra “The Equifax breach of 2017… exemplifies the catastrophic consequences of centralized identity storage”. Tác giả rõ ràng đồng ý với quan điểm này.

Câu 15: NOT GIVEN

• Dạng câu hỏi: Yes/No/Not Given
• Từ khóa: SSI systems, eliminate all privacy concerns
• Vị trí trong bài: Section A
• Giải thích: Bài viết nói SSI cung cấp giải pháp tốt hơn nhưng không khẳng định nó loại bỏ TẤT CẢ mối lo ngại về quyền riêng tư.

Câu 16: NOT GIVEN

• Dạng câu hỏi: Yes/No/Not Given
• Từ khóa: Switzerland’s project, adopted, all EU countries
• Vị trí trong bài: Section A, cuối đoạn
• Giải thích: Bài viết chỉ đề cập Switzerland và Zug đã triển khai nhưng không nói gì về việc tất cả EU áp dụng.

Câu 17: YES

• Dạng câu hỏi: Yes/No/Not Given
• Từ khóa: WHO, counterfeit medications, developing countries
• Vị trí trong bài: Section B, dòng 3-4
• Giải thích: “The World Health Organization estimating that one in ten medical products in developing countries is substandard or falsified”. Tác giả trích dẫn WHO để xác nhận điều này.

Câu 18: NO

• Dạng câu hỏi: Yes/No/Not Given
• Từ khóa: Smart contracts, eliminate, need for lawyers
• Vị trí trong bài: Section C
• Giải thích: Bài viết không khẳng định smart contracts loại bỏ HOÀN TOÀN nhu cầu về luật sư, chỉ nói chúng tự động hóa việc thực thi. Đây là quan điểm quá tuyệt đối mà tác giả không ủng hộ.

Câu 19: iii (Reforming personal data control systems)

• Dạng câu hỏi: Matching Headings
• Section: A
• Giải thích: Section A tập trung vào identity management và self-sovereign identity systems, cho phép người dùng kiểm soát dữ liệu cá nhân của mình.

Câu 20: v (Protecting product authenticity and traceability)

• Dạng câu hỏi: Matching Headings
• Section: B
• Giải thích: Section B thảo luận về supply chain security, pharmaceutical tracking, và diamond provenance – tất cả liên quan đến xác thực và truy xuất nguồn gốc sản phẩm.

Câu 21: iv (Automated enforcement of agreements)

• Dạng câu hỏi: Matching Headings
• Section: C
• Giải thích: Section C giải thích về smart contracts và cách chúng tự động thực thi các thỏa thuận khi điều kiện được đáp ứng.

Câu 22: i (Addressing vulnerabilities in connected devices)

• Dạng câu hỏi: Matching Headings
• Section: D
• Giải thích: Section D tập trung vào IoT devices và cách blockchain giải quyết các lỗ hổng bảo mật trong mạng lưới các thiết bị kết nối.

Câu 23: counterfeit

• Dạng câu hỏi: Summary Completion
• Vị trí: Section B, pharmaceutical discussion
• Giải thích: Bài viết đề cập “Counterfeit medications represent a significant global health threat”.

Câu 24: automatically

• Dạng câu hỏi: Summary Completion
• Vị trí: Section C
• Giải thích: “Smart contracts automatically execute when predetermined conditions are met”.

Câu 25: distributed

• Dạng câu hỏi: Summary Completion
• Vị trí: Section D, dòng 3-4
• Giải thích: “Blockchain offers a distributed security model particularly suited to IoT environments”.

Câu 26: centralized

• Dạng câu hỏi: Summary Completion
• Vị trí: Section D
• Giải thích: Bài viết nói về việc loại bỏ “centralized vulnerabilities” và “centralized authentication servers”.

Passage 3 – Giải Thích

Câu 27: B

• Dạng câu hỏi: Multiple Choice
• Từ khóa: avalanche effect, hash functions
• Vị trí trong bài: Đoạn 2, dòng 4-6
• Giải thích: “Even minute changes to input data produce drastically different outputs – a characteristic known as the avalanche effect”. Đây chính xác là đáp án B.

Câu 28: C

• Dạng câu hỏi: Multiple Choice
• Từ khóa: main limitation, Proof of Work
• Vị trí trong bài: Đoạn consensus mechanisms, dòng về energy
• Giải thích: “The energy consumption required to maintain PoW security has become environmentally unsustainable” được nhấn mạnh như một hạn chế chính.

Câu 29: C

• Dạng câu hỏi: Multiple Choice
• Từ khóa: blockchain trilemma
• Vị trí trong bài: Cuối section về consensus
• Giải thích: Bài viết nói rõ “optimizing for any two of security, scalability, and decentralization necessarily compromises the third”.

Câu 30: B

• Dạng câu hỏi: Multiple Choice
• Từ khóa: quantum computing, threatens blockchain
• Vị trí trong bài: Section Emerging Threats
• Giải thích: “The cryptographic algorithms securing contemporary blockchains – particularly public-key cryptography – are vulnerable to attacks by sufficiently powerful quantum computers”.

Câu 31: B

• Dạng câu hỏi: Multiple Choice
• Từ khóa: DAO attack 2016
• Vị trí trong bài: Section về smart contract vulnerabilities
• Giải thích: “The infamous DAO attack of 2016… exemplified how programming errors in smart contracts can undermine the security”.

Câu 32: C (Computational security)

• Dạng câu hỏi: Matching Features
• Vị trí: Đoạn về cryptographic architecture
• Giải thích: “Creates what cryptographers describe as computational security – security based not on mathematical impossibility but on computational impracticality”.

Câu 33: E (51% attack)

• Dạng câu hỏi: Matching Features
• Vị trí: Section về Proof of Work
• Giải thích: “An attacker would need to control over 50% of the network’s computational power – a 51% attack”.

Câu 34: A (Nothing-at-stake problem)

• Dạng câu hỏi: Matching Features
• Vị trí: Section về Proof of Stake
• Giải thích: “PoS introduces new attack vectors, including nothing-at-stake problems where validators have no cost to vote for multiple competing chain histories”.

Câu 35: D (Zero-knowledge proofs)

• Dạng câu hỏi: Matching Features
• Vị trí: Privacy section
• Giải thích: “Zero-knowledge proofs, which allow verification of information without revealing the information itself”.

Câu 36: B (Formal verification)

• Dạng câu hỏi: Matching Features
• Vị trí: Smart contract security section
• Giải thích: “Formal verification techniques – mathematical proofs of software correctness”.

Câu 37: Shor’s algorithm

• Dạng câu hỏi: Short-answer
• Vị trí: Quantum computing threat section
• Giải thích: “Shor’s algorithm, a quantum algorithm, could theoretically break widely used encryption schemes”.

Câu 38: GDPR / General Data Protection Regulation

• Dạng câu hỏi: Short-answer
• Vị trí: Regulatory challenges section
• Giải thích: “The European Union’s General Data Protection Regulation (GDPR), which grants individuals the ‘right to be forgotten,’ conflicts with blockchain’s immutability”.

Câu 39: public-key cryptography / asymmetric cryptography

• Dạng câu hỏi: Short-answer
• Vị trí: Cryptographic architecture section
• Giải thích: “Public-key cryptography provides the second essential security component, enabling authentication and non-repudiation without requiring parties to share secret information”.

Câu 40: universe’s lifespan / universe lifespan

• Dạng câu hỏi: Short-answer
• Vị trí: Computational security section
• Giải thích: “The time required exceeds not just human lifespans but the projected lifespan of the universe itself”.

5. Từ Vựng Quan Trọng Theo Passage

Passage 1 – Essential Vocabulary

Từ vựng	Loại từ	Phiên âm	Nghĩa tiếng Việt	Ví dụ từ bài	Collocation
digital security	n	/ˈdɪdʒɪtl sɪˈkjʊərəti/	an ninh số	Digital security has become one of the most pressing concerns	enhance digital security, improve digital security
centralized database	n	/ˈsentrəlaɪzd ˈdeɪtəbeɪs/	cơ sở dữ liệu tập trung	Traditional methods rely on centralized databases	maintain centralized database, centralized database system
distributed ledger	n	/dɪˈstrɪbjuːtɪd ˈledʒə/	sổ cái phân tán	Blockchain is essentially a distributed ledger	distributed ledger technology, shared distributed ledger
cryptographic hashing	n	/ˌkrɪptəˈɡræfɪk ˈhæʃɪŋ/	băm mật mã	What makes blockchain secure is cryptographic hashing	use cryptographic hashing, cryptographic hashing function
consensus mechanism	n	/kənˈsensəs ˈmekənɪzəm/	cơ chế đồng thuận	Another crucial security feature is the consensus mechanism	implement consensus mechanism, consensus mechanism ensures
immutable record	n	/ɪˈmjuːtəbl ˈrekɔːd/	bản ghi bất biến	This creates an immutable record of transactions	maintain immutable record, immutable record system
peer-to-peer network	n	/pɪə tə pɪə ˈnetwɜːk/	mạng ngang hàng	The peer-to-peer network structure eliminates single points	peer-to-peer network architecture, decentralized peer-to-peer network
single point of failure	n	/ˈsɪŋɡl pɔɪnt əv ˈfeɪljə/	điểm lỗi duy nhất	Blockchain eliminates single points of failure	avoid single point of failure, single point of failure vulnerability
cyber attack	n	/ˈsaɪbə əˈtæk/	tấn công mạng	Traditional methods are vulnerable to cyber attacks	prevent cyber attacks, sophisticated cyber attacks
e-governance	n	/iː ˈɡʌvənəns/	chính phủ điện tử	Estonia has implemented blockchain in e-governance systems	e-governance systems, e-governance platform
scalability	n	/ˌskeɪləˈbɪləti/	khả năng mở rộng	Scalability is one significant limitation	improve scalability, scalability issues
digital wallet	n	/ˈdɪdʒɪtl ˈwɒlɪt/	ví điện tử	Digital wallets can still be vulnerable to hacking	secure digital wallet, digital wallet security

Passage 2 – Essential Vocabulary

Từ vựng	Loại từ	Phiên âm	Nghĩa tiếng Việt	Ví dụ từ bài	Collocation
data integrity	n	/ˈdeɪtə ɪnˈteɡrəti/	tính toàn vẹn dữ liệu	Blockchain addresses how data integrity can be achieved	maintain data integrity, ensure data integrity
authentication	n	/ɔːˌθentɪˈkeɪʃn/	xác thực	Authentication can be achieved without centralized authorities	user authentication, authentication system
self-sovereign identity	n	/self ˈsɒvrɪn aɪˈdentəti/	danh tính tự chủ	SSI systems offer individuals control over their information	self-sovereign identity framework, implement self-sovereign identity
data breach	n	/ˈdeɪtə briːtʃ/	vi phạm dữ liệu	Numerous high-profile data breaches affect millions	prevent data breaches, major data breach
cryptographic proof	n	/ˌkrɪptəˈɡræfɪk pruːf/	bằng chứng mật mã	Individuals store cryptographic proofs of their identity	provide cryptographic proof, cryptographic proof system
supply chain management	n	/səˈplaɪ tʃeɪn ˈmænɪdʒmənt/	quản lý chuỗi cung ứng	Blockchain is implemented in supply chain management	supply chain management system, optimize supply chain management
counterfeit product	n	/ˈkaʊntəfɪt ˈprɒdʌkt/	sản phẩm giả mạo	Global supply chains face risks from counterfeit products	combat counterfeit products, counterfeit product detection
smart contract	n	/smɑːt ˈkɒntrækt/	hợp đồng thông minh	Smart contracts are self-executing agreements	deploy smart contract, smart contract platform
human error	n	/ˈhjuːmən ˈerə/	lỗi con người	Automation eliminates opportunities for human error	reduce human error, minimize human error
Internet of Things	n	/ˈɪntənet əv θɪŋz/	Internet vạn vật	IoT devices create an expansive attack surface	IoT networks, IoT security
device-to-device authentication	n	/dɪˈvaɪs tə dɪˈvaɪs ɔːˌθentɪˈkeɪʃn/	xác thực thiết bị với thiết bị	IoT devices can verify each other through device-to-device authentication	enable device-to-device authentication
transaction speed	n	/trænˈzækʃn spiːd/	tốc độ giao dịch	Limitations include transaction speed and energy consumption	improve transaction speed, transaction speed optimization
decentralized identity	n	/diːˈsentrəlaɪzd aɪˈdentəti/	danh tính phi tập trung	These initiatives demonstrate decentralized identity is viable	decentralized identity system, decentralized identity management
consensus	n	/kənˈsensəs/	sự đồng thuận	The majority of nodes must reach consensus	achieve consensus, consensus protocol
provenance	n	/ˈprɒvənəns/	nguồn gốc, xuất xứ	The provenance of diamonds has long been a concern	verify provenance, provenance tracking

Passage 3 – Essential Vocabulary

Từ vựng	Loại từ	Phiên âm	Nghĩa tiếng Việt	Ví dụ từ bài	Collocation
cryptographic primitive	n	/ˌkrɪptəˈɡræfɪk ˈprɪmətɪv/	phép toán mật mã cơ bản	Security relies on underlying cryptographic primitives	cryptographic primitive operations, implement cryptographic primitives
hash function	n	/hæʃ ˈfʌŋkʃn/	hàm băm	Hash functions serve as foundation for immutability	cryptographic hash function, secure hash function
public-key cryptography	n	/ˈpʌblɪk kiː ˌkrɪpˈtɒɡrəfi/	mật mã khóa công khai	Public-key cryptography enables authentication	public-key cryptography system, implement public-key cryptography
asymmetric cryptography	n	/ˌeɪsɪˈmetrɪk ˌkrɪpˈtɒɡrəfi/	mật mã bất đối xứng	Also referred to as asymmetric cryptography	asymmetric cryptography algorithm, use asymmetric cryptography
avalanche effect	n	/ˈævəlɑːnʃ ɪˈfekt/	hiệu ứng tuyết lở	Minute changes produce drastically different outputs – the avalanche effect	demonstrate avalanche effect, avalanche effect property
computationally infeasible	adj	/ˌkɒmpjuˈteɪʃənəli ɪnˈfiːzəbl/	không khả thi về mặt tính toán	They are computationally infeasible to reverse	computationally infeasible task, prove computationally infeasible
digital signature	n	/ˈdɪdʒɪtl ˈsɪɡnətʃə/	chữ ký số	Users create a digital signature using their private key	verify digital signature, create digital signature
non-repudiation	n	/nɒn rɪˌpjuːdiˈeɪʃn/	tính không thể chối bỏ	Public-key cryptography enables non-repudiation	ensure non-repudiation, non-repudiation property
brute force	n	/bruːt fɔːs/	vét cạn (tấn công)	An attacker could break protections through brute force methods	brute force attack, prevent brute force
Proof of Work	n	/pruːf əv wɜːk/	bằng chứng công việc	The original consensus mechanism, Proof of Work	Proof of Work consensus, implement Proof of Work
51% attack	n	/ˌfɪfti wʌn pəˈsent əˈtæk/	tấn công 51%	To manipulate blockchain requires a 51% attack	prevent 51% attack, vulnerable to 51% attack
Proof of Stake	n	/pruːf əv steɪk/	bằng chứng cổ phần	Proof of Stake replaces computational work with economic stake	Proof of Stake mechanism, transition to Proof of Stake
blockchain trilemma	n	/ˈblɒktʃeɪn traɪˈlemə/	bộ ba nan đề blockchain	The blockchain trilemma suggests inherent trade-offs	solve blockchain trilemma, blockchain trilemma problem
quantum computing	n	/ˈkwɒntəm kəmˈpjuːtɪŋ/	điện toán lượng tử	Quantum computing represents an existential threat	quantum computing threat, quantum computing advances
quantum supremacy	n	/ˈkwɒntəm suːˈpreməsi/	ưu thế lượng tử	The timeline for achieving quantum supremacy is uncertain	achieve quantum supremacy, quantum supremacy milestone
post-quantum cryptography	n	/pəʊst ˈkwɒntəm ˌkrɪpˈtɒɡrəfi/	mật mã hậu lượng tử	Research into post-quantum cryptography has accelerated	post-quantum cryptography algorithms, implement post-quantum cryptography
smart contract vulnerability	n	/smɑːt ˈkɒntrækt ˌvʌlnərəˈbɪləti/	lỗ hổng hợp đồng thông minh	Smart contract vulnerabilities constitute a significant challenge	identify smart contract vulnerabilities, fix smart contract vulnerabilities
formal verification	n	/ˈfɔːməl ˌverɪfɪˈkeɪʃn/	xác minh hình thức	Formal verification provides mathematical proofs of correctness	formal verification techniques, formal verification tools
transaction graph analysis	n	/trænˈzækʃn ɡrɑːf əˈnæləsɪs/	phân tích đồ thị giao dịch	Transaction graph analysis can potentially de-anonymize users	conduct transaction graph analysis, transaction graph analysis methods
zero-knowledge proof	n	/ˈzɪərəʊ ˈnɒlɪdʒ pruːf/	bằng chứng không tiết lộ	Zero-knowledge proofs allow verification without revealing information	implement zero-knowledge proofs, zero-knowledge proof protocol
ring signature	n	/rɪŋ ˈsɪɡnətʃə/	chữ ký vòng	Ring signatures obscure the true signer among a group	use ring signatures, ring signature scheme
regulatory compliance	n	/ˈreɡjələtəri kəmˈplaɪəns/	tuân thủ quy định	Systems must balance privacy with regulatory compliance	ensure regulatory compliance, regulatory compliance requirements

Kết bài

Qua bài thi IELTS Reading mẫu về chủ đề “How blockchain is improving digital security”, bạn đã được trải nghiệm một đề thi hoàn chỉnh với ba passages có độ khó tăng dần, phản ánh chính xác cấu trúc của kỳ thi IELTS thực tế. Chủ đề blockchain và an ninh số không chỉ là một trong những xu hướng công nghệ quan trọng nhất hiện nay mà còn là một topic phổ biến trong các đề thi IELTS gần đây.

Ba passages trong đề thi này đã cung cấp cho bạn cái nhìn toàn diện về công nghệ blockchain, từ những khái niệm cơ bản (Passage 1) đến các ứng dụng thực tế trong nhiều lĩnh vực khác nhau (Passage 2), và cuối cùng là những thách thức kỹ thuật phức tạp cũng như triển vọng tương lai của công nghệ này (Passage 3). Mỗi passage không chỉ kiểm tra khả năng đọc hiểu của bạn mà còn giúp mở rộng kiến thức về một chủ đề công nghệ quan trọng.

Đáp án chi tiết kèm theo giải thích cụ thể cho từng câu hỏi sẽ giúp bạn hiểu rõ tại sao một đáp án đúng, cách paraphrase được sử dụng trong câu hỏi và passage, cũng như vị trí chính xác của thông tin trong bài đọc. Đây là kỹ năng thiết yếu để đạt band điểm cao trong IELTS Reading. Bảng từ vựng theo từng passage cung cấp hơn 40 từ và cụm từ học thuật quan trọng, hoàn chỉnh với phiên âm, nghĩa tiếng Việt, ví dụ trong ngữ cảnh và các collocation thường gặp – tất cả đều là vốn từ vựng quý giá cho bài thi IELTS của bạn.

Hãy nhớ rằng, để đạt kết quả tốt trong IELTS Reading, bạn cần luyện tập thường xuyên với các đề thi đa dạng về chủ đề và độ khó. Đề thi mẫu này cung cấp một nền tảng vững chắc, nhưng sự tiến bộ thực sự đến từ việc phân tích sai lầm, học từ vựng trong ngữ cảnh, và rèn luyện các kỹ thuật làm bài hiệu quả. Chúc bạn ôn tập hiệu quả và đạt được band điểm IELTS mong muốn!