ELI5: Explain Like I'm 5

Yao's Millionaires' Problem

Imagine you have $10 and your friend also has $10. You want to figure out how to split your combined amount of money fairly between the two of you. This is what Yao's Millionaires' Problem is trying to solve, but on a much larger scale.

Let's say there are two millionaires, one with $1 billion and another with $2 billion. They want to figure out how to split their combined $3 billion fairly between the two of them, without revealing how much money they have individually. This is where Yao's Millionaires' Problem comes in.

To solve this problem, each millionaire will create a secret number that only they know. These secret numbers are represented in binary form, which is a mathematical language that uses only 1s and 0s (kind of like a secret code).

The millionaires then use a special algorithm (or set of instructions) to perform calculations on their secret numbers. The algorithm ensures that the end result of the calculation will be based on both secret numbers, but neither millionaire will know what the other's secret number is.

Once the calculation is complete, the millionaires can look at the result and agree on a fair way to divide the $3 billion between them based on the calculated result. For example, if the calculated result is 0, they could agree to split the money equally (each getting $1.5 billion). If the calculated result is closer to 1 or 2, they might agree to a different split.

Overall, Yao's Millionaires' Problem is a way for people to perform calculations and share information without revealing sensitive or confidential data. It's like a secret handshake between two super wealthy individuals who want to work together without revealing too much about themselves.