Blockchain use cases beyond crypto - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a key benefit of using blockchain for supply chain management?

Blockchain provides transparent and tamper-proof tracking of goods from origin to delivery, improving trust and reducing fraud.

beginner

How does blockchain improve healthcare data management?

It secures patient records with encryption and allows controlled sharing between authorized parties, enhancing privacy and data integrity.

intermediate

What role does blockchain play in digital identity verification?

Blockchain enables users to control their identity data securely and share it without relying on a central authority, reducing identity theft risks.

intermediate

Explain how blockchain can be used in voting systems.

Blockchain can create transparent, tamper-resistant voting records that anyone can verify, increasing election trust and reducing fraud.

advanced

What is a smart contract and how does it extend blockchain use beyond cryptocurrency?

A smart contract is a self-executing code on blockchain that automates agreements and processes without intermediaries, enabling applications like insurance claims and real estate deals.

Which of the following is NOT a benefit of blockchain in supply chain management?

A Improved transparency

B Reduced fraud

C Faster physical delivery of goods

D Tamper-proof records

Blockchain improves tracking and transparency but does not speed up the physical movement of goods.

How does blockchain help secure healthcare data?

A By storing data in a central server

B By encrypting data and controlling access

C By deleting old records automatically

D By sharing data publicly

Blockchain encrypts data and allows only authorized parties to access it, protecting privacy.

What is a smart contract?

A A self-executing program on blockchain

B A blockchain mining tool

C A cryptocurrency wallet

D A legal document signed digitally

Smart contracts are programs on blockchain that run automatically when conditions are met.

In digital identity, blockchain helps by:

A Centralizing all identity data

B Replacing government-issued IDs

C Making identity data public for verification

D Allowing users to control and share their data securely

Blockchain lets users control their identity data and share it securely without a central authority.

Why is blockchain useful in voting systems?

A It creates transparent and tamper-resistant vote records

B It speeds up vote counting by humans

C It allows anyone to change votes

D It replaces physical ballots with paper

Blockchain makes voting records transparent and hard to tamper with, increasing trust.

Describe three real-world uses of blockchain technology beyond cryptocurrency.

Think about industries where trust and data security are important.

Explain how smart contracts extend blockchain's usefulness beyond just handling money.

Consider how agreements can happen automatically without people in the middle.

Practice

1. Which of the following is a common use of blockchain technology beyond cryptocurrency?

easy

A. Creating new digital currencies only

B. Running traditional centralized databases

C. Tracking the origin and movement of goods in supply chains

D. Replacing all internet servers

Solution

1. Step 1: Understand blockchain beyond money

   Blockchain is used to keep safe and clear records, not just for digital money.

2. Step 2: Identify common non-crypto uses

   Tracking goods in supply chains is a popular use case to ensure transparency and trust.

3. Final Answer:

   Tracking the origin and movement of goods in supply chains -> Option C

4. Quick Check:

   Blockchain use beyond crypto = Tracking goods [OK]

Hint: Think of blockchain as a secure record keeper beyond money [OK]

Common Mistakes:

• Thinking blockchain only creates cryptocurrencies
• Confusing blockchain with regular databases
• Assuming blockchain replaces all internet servers

2. Which syntax correctly describes a smart contract in blockchain?

easy

A. contract SmartContract { function run() public {} }

B. smart contract run() {}

C. contract = SmartContract()

D. function smartContract run()

Solution

1. Step 1: Recognize smart contract syntax

   Smart contracts are written like small programs with a contract keyword and functions.

2. Step 2: Check syntax correctness

   contract SmartContract { function run() public {} } uses correct syntax with 'contract' keyword and function declaration.

3. Final Answer:

   contract SmartContract { function run() public {} } -> Option A

4. Quick Check:

   Correct smart contract syntax = contract SmartContract { function run() public {} } [OK]

Hint: Look for 'contract' keyword and function inside braces [OK]

Common Mistakes:

• Missing 'contract' keyword
• Using assignment instead of declaration
• Incorrect function declaration syntax

3. What will be the output of this simplified blockchain smart contract code snippet?

mapping(address => uint) public votes;
function vote() public {
  votes[msg.sender] += 1;
}
vote() called twice by same address.

medium

A. votes[msg.sender] = 1

B. votes[msg.sender] = 2

C. votes[msg.sender] = 0

D. Error: duplicate voting not allowed

Solution

1. Step 1: Understand the vote function

   Each call to vote() increases the caller's vote count by 1 in the votes mapping.

2. Step 2: Calculate votes after two calls

   Calling vote() twice adds 1 twice, so votes[msg.sender] becomes 2.

3. Final Answer:

   votes[msg.sender] = 2 -> Option B

4. Quick Check:

   Two votes increment count to 2 [OK]

Hint: Each call adds 1, so two calls add up to 2 [OK]

Common Mistakes:

• Assuming only one vote allowed
• Thinking votes reset after each call
• Confusing mapping with array

4. Identify the error in this blockchain voting smart contract snippet:

mapping(address => bool) public voted;
function vote() public {
  require(!voted[msg.sender]);
  voted[msg.sender] = true;
  votes += 1;
}

medium

A. votes variable is not declared

B. require statement syntax is wrong

C. voted mapping should be uint not bool

D. Function vote() missing return type

Solution

1. Step 1: Check variable declarations

   The code uses 'votes += 1' but 'votes' is not declared anywhere.

2. Step 2: Verify other parts

   require syntax and voted mapping type are correct; vote() functions in Solidity do not need return type.

3. Final Answer:

   votes variable is not declared -> Option A

4. Quick Check:

   Undeclared variable 'votes' causes error [OK]

Hint: Check if all variables used are declared [OK]

Common Mistakes:

• Assuming require syntax is wrong
• Thinking bool mapping is incorrect
• Expecting return type in void functions

5. You want to build a blockchain system to manage digital rights for music tracks. Which feature is most important to include beyond basic blockchain storage?

hard

A. Anonymous voting for favorite tracks

B. A cryptocurrency token for trading music

C. A centralized database for faster queries

D. Smart contracts to automate royalty payments

Solution

1. Step 1: Understand digital rights management needs

   Managing rights requires automatic, trustworthy payment distribution to artists.

2. Step 2: Identify blockchain feature for automation

   Smart contracts can run code to automate royalty payments when music is used or sold.

3. Step 3: Evaluate other options

   Cryptocurrency tokens and voting are unrelated; centralized database loses blockchain benefits.

4. Final Answer:

   Smart contracts to automate royalty payments -> Option D

5. Quick Check:

   Automate payments with smart contracts [OK]

Hint: Use smart contracts to automate rules and payments [OK]

Common Mistakes:

• Choosing cryptocurrency token instead of automation
• Using centralized database losing blockchain trust
• Confusing voting with rights management