Summer of Math Exposition

How to Cheat with Math | The Russian Cards Problem

Our entry showcases the russian cards problem. This is a question about how to transfer information unencrypted whilst maintaining security. It show cases interesting ideas about the logic of knowledge. We made our entry as simple as possible.

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5.8 Overall score*
35 Votes
11 Comments
Rank 18

Comments

nice motivation and cute problem, could be more fleshed out with more of a punchline

5.3

I expected it would cover zero knowledge concept like in zero knowledge authentication. But it didn't. It's probably impossible for this game. Just a guess. But provided example in solution clearly shows it's not satisfy zero knowledge. Because Eve can infer three possible card hands. For zero knowledge, all C(6, 3) = 20 options should be equally likely.

4.8

Could you expand on how a method should generalize? If it applies to ANY distribution of cards, then what about alice having 1 card, bob having 1 card and eve having 3 cards?

4.5

Nice article. The explanation of the solution could be better.

5.7

You make it very clear why this solution works. But I don't get much intuition for where the particular range of hands come from. Why include those and not, say, 136? (Also, if you're going to use those particular hands, the Fano plane is a great visual.)

4.3

Actually, I love the way you lead us to the solution, which is the truly proper way to analyse and learn, but the process could be more detailed. For example, when it comes to the solution, you can add the motivation except for the reasonableness. Though simple, the article is fascinating. Good job!

7.1

Introduces an interesting concept in a fun way and does not require specific knowledge, the drawings are funky as well. I love it!

7.4

I like how interactive this was - encouraging the reader to experience and think about the concepts themselves. Moreover, it is exactly as the authors describe - a simple solution that is accessible to most non-experts. It is also compact and allows the reader to look up the more complex concepts themselves. If I was to suggest anything, it would be to add more clarity on False Solution 2 - Bob only needs to know what Alice says to know that Eve has 5.

6.9

I think the presentation was overall excellent. I love how you motivated the problem, and kept it interesting overall.

8.3

i am a bit confused and cannot understand what was it...

6.1

You have some typos like Eavesdropper (a is missing) and his (when Eve is a woman name). False solution 2 doesn't make sense if they are telling the truth, maybe the example should be different. Interesting solution in any case!

5