1. 14

  2. 9

    Great summary of how SSS works. There’s also [1] if anyone is looking for a prepackaged tool.

    The other day I was thinking about this: Say I’m writing a tool, and I want to add secret sharing. I’ve already got a library such as libsodium baked in. Unfortunately, secret sharing isn’t natively supported in libsodium (and analogues). What if I just put together all the possible k-of-n combinations and wrapped up the secret in nested “boxes” (as libsodium calls them)? How inefficient would that be?

    SSS takes space that is linear in k. It turns out, doing the crazy thing I just described takes O(n^k). So that’s exponential in k and polynomial in n.

    [1] http://point-at-infinity.org/ssss/

    1. 1

      I first found out about this when I saw it in real-world use by Naomi Wu, who is Chinese and somewhat famous, which results in extra police attention.