Consensus mechanisms overview in Blockchain / Solidity - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define the consensus mechanism used in Proof of Work.

Blockchain / Solidity

consensus = "[1]"

Drag options to blanks, or click blank then click option'

AByzantine Fault Tolerance

BProof of Stake

CDelegated Proof

DProof of Work

Attempts:

3 left

💡 Hint

Common Mistakes

Confusing Proof of Work with Proof of Stake

Using Delegated Proof as the main consensus

The consensus mechanism used in Bitcoin and many early blockchains is Proof of Work.

2fill in blank

medium

Complete the code to check if the consensus mechanism is energy efficient.

Blockchain / Solidity

if consensus == "[1]":
    print("Energy efficient")
else:
    print("Not energy efficient")

Drag options to blanks, or click blank then click option'

AProof of Stake

BProof of Work

CProof of Authority

DProof of Capacity

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing Proof of Work as energy efficient

Confusing Proof of Authority with energy efficiency

Proof of Stake is known for being more energy efficient than Proof of Work.

3fill in blank

hard

Fix the error in the code to correctly identify the consensus mechanism that uses voting among nodes.

Blockchain / Solidity

if consensus == "[1]":
    print("Uses voting among nodes")

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AProof of Work

BByzantine Fault Tolerance

CProof of Stake

DProof of Capacity

Attempts:

3 left

💡 Hint

Common Mistakes

Confusing it with Proof of Stake

Choosing Proof of Work which is puzzle-based

Byzantine Fault Tolerance consensus involves nodes voting to agree on the next block.

4fill in blank

hard

Fill both blanks to create a dictionary mapping consensus mechanisms to their main characteristic.

Blockchain / Solidity

consensus_info = {
    "Proof of Work": "[1]",
    "Proof of Stake": "[2]"
}

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AHigh energy consumption

BLow energy consumption

CFast finality

DDecentralized voting

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up energy consumption characteristics

Using voting or finality terms incorrectly

Proof of Work consumes high energy, while Proof of Stake is low energy.

5fill in blank

hard

Fill both blanks to create a dictionary comprehension filtering consensus mechanisms with energy consumption less than 100.

Blockchain / Solidity

energy_use = {
    "PoW": 1000,
    "PoS": 10,
    "BFT": 50
}
low_energy = {k: v for k, v in energy_use.items() if v {BLANK_2}} {{BLANK_2}}

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A:

B<

C100

D==

Attempts:

3 left

💡 Hint

Common Mistakes

Using '==' instead of '<' in the condition

Forgetting the colon ':' in the comprehension

The dictionary comprehension uses ':' to map keys to values, and filters values less than 100.