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Comment by zetsurin

1 day ago

[Vinge](https://en.wikipedia.org/wiki/Vernor_Vinge) was a professor of mathematics and computer science. I'd expect him to get things right. Funny enough I don't remember that bit at all from fire upon the deep.

From Chapter 8, available online at https://deepness.trmm.net/c08b/

"Our main cargo is a one-time cryptographic pad. The source is Commercial Security at Sjandra Kei; the destination is the certificants' High colony. It was the usual arrangement: We're carrying a one-third xor of the pad. Independent shippers are carrying the others. At the destination, the three parts would be xor'd together. The result could supply a dozen worlds' crypto needs on the Net for --"

  • Doesn’t mention anything about quantum there though. Symmetric keys are secure enough against a cryptographically relevant quantum computer, but OTP provides information theoretic security. As GGP mentioned AES should be fine as far as we know for the foreseeable future regardless, but for all we know some brilliant cryptographer will in fact find a flaw. With OTP one doesn’t have to worry about even the slightest chance that could happen. This excerpt also may be alluding to threshold cryptography (Shamir’s secret sharing) which got.. shared.. here recently as well, and also happens to be information theoretically secure.

    • > Doesn’t mention anything about quantum there though

      Because the book was written 2 years before it was discovered quantum computers had applications to cryptanalysis of RSA.

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