Blockchain Technology - SSS 2 Note
BLOCKCHAIN TECHNOLOGY
Class: SSS 2
Term: Third Term
Week: 4
Topic: Blockchain Technology
Duration: 80 Minutes (Double Period)
Learning Objectives
By the end of the lesson, students should be able to:
- Define blockchain technology.
- Explain the basic concept and operation of a blockchain.
- Describe the relationship between blockchain and cryptocurrency.
- Identify uses of blockchain beyond finance.
- Explain the advantages and challenges of blockchain technology.
1. Introduction to Blockchain Technology
Digital technologies allow people and organisations to create, store and exchange information electronically. In many systems, information is stored in a central database controlled by one organisation. Blockchain technology provides another way of recording and sharing information among multiple participants.
Blockchain became widely known through cryptocurrencies such as Bitcoin. However, its possible applications extend beyond digital currencies to areas such as supply chain management, record verification and digital identity systems.
2. Meaning of Blockchain Technology
A blockchain can be maintained by several computers or participants in a network. Depending on its design, participants may share copies of the records and follow agreed rules for adding new information.
Once a block has been accepted and linked to the chain, changing its contents is designed to be difficult to do without detection. However, blockchain systems are not automatically free from errors, fraud or security problems.
2.1 Meaning of a Block
A block is a collection of recorded information. Depending on the blockchain, it may contain transaction details, a timestamp and technical information used to connect it to other blocks.
2.2 Meaning of a Chain
A chain is the sequence formed when blocks are linked together. Cryptographic hashes help connect each block to the preceding block.
2.3 Meaning of a Distributed Ledger
A distributed ledger is a record of information shared and maintained across multiple computers or participants. In many blockchain networks, participants maintain copies of the ledger according to the network's rules.
2.4 Meaning of Cryptographic Hash
A cryptographic hash is a digital value produced from information using a mathematical function. It helps identify the contents of a block. If the information changes, its hash will generally change as well, making unauthorised alterations easier to detect.
3. Basic Concept and Operation of Blockchain
The basic operation of a blockchain involves recording information, checking its validity, grouping records into blocks and linking accepted blocks to the existing chain.
- Information is submitted: A participant submits a transaction or another record to the network.
- Information is checked: The network follows its rules to check whether the submitted information is valid.
- Records are grouped: Valid records may be organised into a block.
- The block is accepted: The network uses an agreed method, called a consensus mechanism, to determine which block should be added.
- The block is linked: The accepted block is linked to the previous block using cryptographic information.
- The ledger is updated: Network participants update their records according to the system's rules.
Simple Illustration
| Block 1 | Block 2 | Block 3 |
|---|---|---|
| Record A Previous hash: None |
Record B Previous hash: Hash of Block 1 |
Record C Previous hash: Hash of Block 2 |
The illustration shows how blocks can be linked in sequence. If information in an earlier block is altered, the connection between blocks may no longer match. The network's rules and security mechanisms help detect or reject unauthorised changes.
4. Relationship Between Blockchain and Cryptocurrency
Blockchain and cryptocurrency are related, but they do not mean the same thing.
For example, Bitcoin uses a blockchain to record transactions involving bitcoin. The blockchain provides a shared transaction history, while bitcoin is the digital asset being transferred.
| Blockchain | Cryptocurrency |
|---|---|
| A technology for recording and linking digital records. | A type of digital asset. |
| Can be used for financial and non-financial purposes. | May be transferred or used within a digital financial system. |
| May support applications that do not involve digital money. | Often relies on a blockchain or another digital record system. |
| Examples include blockchain systems used for transaction records and product tracking. | Examples include Bitcoin and Ether, the asset associated with the Ethereum network. |
5. Uses of Blockchain Beyond Finance
Blockchain can be used in different fields where organisations need to record, share or verify information. Its suitability depends on the problem being solved and the design of the system.
5.1 Supply Chain Management
Businesses may use blockchain-based records to track the movement of goods from producers to distributors and retailers. This can help participants check where a product has passed through the supply chain.
Example: A food company could use a shared record to document when food products leave a farm, reach a warehouse and arrive at a shop.
5.2 Education and Certificates
Educational institutions may explore blockchain-based systems to help verify certificates and other academic records.
Example: An employer could use a verification system to check whether a digital certificate was issued by a recognised institution.
5.3 Healthcare Records
Blockchain may support the secure verification and sharing of selected healthcare records between authorised organisations. Sensitive medical information still requires strong privacy controls and appropriate access restrictions.
5.4 Digital Identity
Blockchain-based systems may help people manage or verify selected digital identity claims. A blockchain does not automatically prove that information entered into it is true; the information must be verified through suitable processes.
5.5 Property and Asset Records
Some systems can use blockchain to record the history or transfer of assets. Legal ownership still depends on applicable laws and recognised procedures, not merely on the presence of a digital record.
5.6 Smart Contracts
A smart contract is a computer program stored or executed on a blockchain platform that carries out specified actions when programmed conditions are met.
Example: A smart contract could release a digital payment when a defined condition is satisfied. The program must still be designed and tested carefully because coding errors can cause problems.
5.7 Record Verification and Data Integrity
Organisations may use blockchain to help verify that records have not been altered after they were recorded. This can be useful for audit trails and document verification.
5.8 Voting Research and Digital Participation
Blockchain has been explored for some voting and participation systems. However, using blockchain does not automatically make an election secure, private, accessible or resistant to coercion. Real elections require comprehensive technical, legal and operational safeguards.
6. Advantages of Blockchain Technology
The possible advantages of blockchain include the following:
- Shared records: Approved participants can work with a common record of transactions or events.
- Tamper resistance: Cryptographic links and network rules can make unauthorised changes easier to detect.
- Traceability: Records can help participants follow the history of transactions or products.
- Transparency: Some blockchain networks allow participants to inspect records according to their access rights.
- Reduced dependence on a single record keeper: Some blockchain designs allow multiple participants to maintain records instead of relying entirely on one central organisation.
- Automation: Smart contracts can automate certain actions when their programmed conditions are met.
- Improved audit trails: Time-ordered records can help organisations review what was recorded and when.
7. Challenges and Limitations of Blockchain
Despite its potential benefits, blockchain has limitations that must be considered before it is used.
- High energy use in some systems: Certain blockchains use energy-intensive proof-of-work methods. Other designs may use substantially less energy.
- Scalability: Some networks may process transactions more slowly or handle fewer transactions than required for large-scale applications.
- Cost: Developing, maintaining and using a blockchain system may involve technical and operational expenses.
- Privacy concerns: Information recorded on a blockchain may be difficult to remove. Sensitive personal information should not be placed on a public blockchain without careful assessment.
- Irreversible errors: Some systems make recorded transactions difficult to reverse. Incorrect transactions or programming errors can therefore be costly to correct.
- Technical complexity: Designing and managing blockchain applications requires specialised knowledge.
- Legal and regulatory uncertainty: Rules governing digital assets and blockchain applications differ across countries and may change.
- False information: Blockchain can preserve a record, but it cannot automatically guarantee that the information entered was accurate in the first place.
8. Blockchain Compared with a Traditional Database
| Feature | Traditional Database | Blockchain |
|---|---|---|
| Record management | Often managed by a central organisation. | May be maintained by multiple participants, depending on the design. |
| Changing records | Authorised users may edit or delete records according to permissions. | Recorded information is often designed to be tamper-resistant, although correction methods depend on the system. |
| Access | Controlled by the database owner and its access rules. | May be public or restricted to approved participants. |
| Best use | Suitable for many everyday applications requiring efficient storage and updates. | May be useful where multiple parties need a shared, verifiable record and have reasons not to rely entirely on one record keeper. |
Blockchain is not always better than a traditional database. The appropriate choice depends on the purpose, cost, privacy requirements, performance needs and level of trust among participants.
9. Class Activity
Activity: Demonstrating a Simple Blockchain
- Work in groups of three to five students.
- Let each student represent one block in a chain.
- Write a sample classroom record on each paper block, such as “Book borrowed,” “Book returned” or “Book checked.”
- Number the blocks in order and write the previous block's number on each block, except the first.
- Discuss how changing an earlier record could affect the chain of records.
- Explain why real blockchain systems use cryptographic methods and agreed network rules rather than relying only on numbered paper blocks.
Discussion questions:
- What does each paper block represent?
- Why is the order of the records important?
- How could a shared record help several people?
- What problems might occur if incorrect information is recorded?
10. Summary
Blockchain technology is a method of recording information in linked blocks. Cryptographic techniques help connect the blocks and make unauthorised changes easier to detect. Many cryptocurrencies use blockchain to record transactions, but blockchain can also support applications such as product tracking, certificate verification, digital identity and smart contracts.
Possible benefits include shared records, traceability, tamper resistance and improved audit trails. Challenges include cost, scalability, privacy concerns, technical complexity and the possibility of recording false information. Blockchain should therefore be selected only when its features are suitable for the problem being solved.
11. Evaluation Questions
- Define blockchain technology.
- What is a block in a blockchain?
- Explain the meaning of a distributed ledger.
- State the relationship between blockchain and cryptocurrency.
- Mention four uses of blockchain beyond finance.
- Explain four advantages of blockchain technology.
- State four challenges of blockchain technology.
- What is a smart contract?
- Give two differences between a traditional database and a blockchain.
- Why does blockchain not automatically guarantee that recorded information is true?
12. Assignment
Answer the following questions in your notebook:
- Explain the basic operation of blockchain technology in your own words.
- Describe three uses of blockchain beyond cryptocurrency.
- List five advantages and five challenges of blockchain technology.
- Explain why an organisation might choose a traditional database instead of a blockchain.
- Draw a simple diagram showing three linked blocks. Label each block and show how each block connects to the previous one.
13. Interactive Revision Quiz
Choose one answer for each question, then click Mark Quiz to check your score.
Comments
Post a Comment