… or, as Sheon Han explains, maybe not…
Imagine you had some useful knowledge — maybe a secret recipe, or the key to a cipher. Could you prove to a friend that you had that knowledge, without revealing anything about it? Computer scientists proved over 30 years ago that you could, if you used what’s called a zero-knowledge proof.
For a simple way to understand this idea, let’s suppose you want to show your friend that you know how to get through a maze, without divulging any details about the path. You could simply traverse the maze within a time limit, while your friend was forbidden from watching. (The time limit is necessary because given enough time, anyone can eventually find their way out through trial and error.) Your friend would know you could do it, but they wouldn’t know how.
Zero-knowledge proofs are helpful to cryptographers, who work with secret information, but also to researchers of computational complexity, which deals with classifying the difficulty of different problems. “A lot of modern cryptography relies on complexity assumptions — on the assumption that certain problems are hard to solve, so there has always been some connections between the two worlds,” said Claude Crépeau, a computer scientist at McGill University. “But [these] proofs have created a whole world of connection.”…
More about how zero-knowledge proofs allow researchers conclusively to demonstrate their knowledge without divulging the knowledge itself: “How Do You Prove a Secret?,” from @sheonhan in @QuantaMagazine.
* Johann Wolfgang von Goethe
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As we stay sub rosa, we might recall that today (All Saints Day) is the (fictional) birthday of Hello Kitty (full name: Kitty White); she was born in a suburb of London. A cartoon character designed by Yuko Shimizu (currently designed by Yuko Yamaguchi), she is the property of the Japanese company Sanrio. An avatar of kawaii (cute) culture, Hello Kitty is one of the highest-grossing media franchises of all time; Hello Kitty product sales and media licensing fees have run as high as $8 billion a year.
