[Cryptography] quantum computers & crypto

[Peter Gutmann]

cherry <cherry at cpal.pw> writes:

>Put money on the table, give marketers the opportunity to sell solutions to
>deep philosophical problems, what are you going to get?

Recycling a post to the CFRG list:

Quantum cryptanalysis consists of a cryptographer drawing a pencil sketch of a
cryptanalysis mechanism with a dotted outline in the middle labelled
"functioning quantum computer goes here".  The same technique is useful for
designing faster-than-light spacecraft, matter replicators, and other things.

If we are going to look at things like this then we also need to look into
algorithms that address, at the very least, the following fields:

* Time-travel resistant cryptography ("functioning time machine goes here"),
https://colinoflynn.com/2019/09/a-call-for-time-travel-resistant-cryptography-ttrc.

* Space-alien resistant cryptography (they could land at any minute and give
us a time-travel device or quantum computer).

* Homeopathic[0] cryptanalysis, where you take a single bit of known
plaintext, dilute it 100:1 with ciphertext, dilute that again 100:1, dilute
that again 100:1, and then your encryption keys drop out.

Peter.

[0] Homeopathy is fun.  One of the many different forms of the ritual, the
    Korsakovian method, involves putting the substance of interest in a
    container, pouring it out, pouring in water, pouring it out, etc, until
    the necessary dilution is achieved.

    When you run your dishwasher, you pour out the original substance, then
    the dishwasher arm swings around and fills the container with water, then
    it drains out again, then it gets refilled, etc.  So every time you run
    your dishwasher you're creating homeopathic lasagna.

    Not a lot of people know that.