Comparison

Problem

"How to transfer the sensors readings (quality of the opinion) into a secure dissemination strategy that is similar to the existing approach?"

Comparison

Feature	Classical approach	Blockchain approach
Number of used opinions for voting strategy	Last 2 opinions in robot's memory	Last 2 opinions in robot's blockchain
Dissemination State	Time: proportional to sensor readings p, using a sample from an exponential distribution with pg, g = 10 Broadcasting: During the entire phase Listening: Only in the last 3s of the phase Peers: Send opinions to peers if distance is below 50 cm	Dissemination strategy: see strategies below Dissemination time: see strategies below Peers: Connect to peers (i.e., to their Ethereum process) if distance is below 50 cm
Exploration State	Time: Sample from an exponential distribution with σ = 10	Time: Sample from an exponential distribution with σ = 10 Peers: Not connected to any peers

Strategies

Strategy 1: Amount of transactions

• Send a transaction with 1 ether in each timestep of the dissemination state
• Expected behavior: The stronger the opinion, the more transactions will be sent; therefore it is more likely that one of these transactions belong to the last two in the blockchain
• Disadvantage: Is this strategy close enough (amount of votes vs. time of dissemination) to the other approach?

Strategy 2: Direct modulation

• Send one transaction each time a robot enters the dissemination state, include amount of ether that is proportional to the quality of the opinion
• Expected behavior: Should be very similar to the non-secure version; the last two votes in the blockchain
• Disadvantage: None. Should be directly comparable to the DC strategy

Strategy 3: Mining time

• Make mining time proportional to the quality of the opinion
• Expected behavior:

Strategy 4: Hash-puzzle

• Robots have to solve a (hash-based) puzzle, whose difficulty is proportional to the quality of the opinion they want to send
• Expected behavior:

Strategy 5: Most similar

• Only connect to neighbors in the dissemination state
• The longer a robot is in the state, the more other robots will receive its opinion
• Problem: When do robots mine? Only in the last x seconds (fixed)? Or for a time proportional to their opinion?
• Expected behavior:

Alternative

• Use an alternative approach that is not similar to Gabri's approach
• Expected behavior:
• Advantages: Can tailor approach to the blockchain
• Disadvantages: Might be harder to compare the approach and show its advantages