Nov 9th (day 27): Zero knowledge proofs

November 9th, 2008 by Hang

In cryptography, a zero knowledge proof is a way to prove that something is true without knowledge of what that thing is. For example, I could prove you know the password to a profile by having you insert the text “Hang, I own this profile qX45s” in the about me section but this would not give me knowledge about what the password is.

I use the term zero knowledge proof as ways of proving whether an assertion is correct without knowing anything about the domain itself. This is as opposed to “first order proofs” in which the proof relies on direct application of domain knowledge to determine truth. For example, if you were presented with a claim that the WTC towers were brought down with timed explosives, a zero knowledge proof would involve looking at who was making the claims, how coherently they are able to make their point, who are the major parties who disagree etc. A first order proof would computing the structural integrity of the buildings, verifying the melting points of steel and how it deforms under high temperature and assessing similar building collapses.

Zero knowledge proofs are powerful because they allow us to leverage the insight that we gain one domain to practically all aspects of life. Given powerful enough zero knowledge proofs, we can attempt to answer questions as diverse as “Is postmodernism bullshit”, “Is global warming real”, “Which president has better economic policies” and “Is the God described by any major religions real”. Unfortunately, most people’s toolbox of zero knowledge proofs suck.

Common zero knowledge proofs include things like whether the person sounds like they know what they’re talking about, whether they have an advanced degree from a prestigious institution, or simply whether they agree with you. Most of these zero knowledge proofs develop as instinctive heuristics and we never really give them much consideration.

Here are some basic zero knowledge proofs which I’ve found to be useful:

  • How willing are they to admit the weaknesses and flaws in their own position?
  • How well can someone argue against their own position? How aware are they of the best arguments from the other side?
  • How willing are they to show you their raw data, their raw speculations and the tools neccesary for you to reach the position they are at?
  • Do they have the support and endorsement of others who you know and trust according to similar zero knowledge proof or first order proof criteria?
  • Have similar claims been made in the past and been systematically proven wrong?

A powerful toolbox of zero knowledge proofs is the most efficient way of applying analytical insight to a variety of fields. At the same time, even the best zero knowledge proofs cannot match a proper first order proof in determining power and the evidence gleaned from zero knowledge proofs must be placed in it’s context.

Tags: , ,
Also featured in blogs: Figuring Shit Out
| Comments (6)

  • http://edmundintokyo.wordpress.com/ Edmund in Tokyo

    One more very useful zero-knowledge proof along the same lines: How bad are the opponents’ arguments? This is particularly useful in political situations where there’s a group on the other side with plenty of resources to attack a case. If they’ve had to resort to misleading use of statistics and logic that doesn’t stand up to a bit of thought, there’s a good chance that the case they’re attacking is sound.

  • http://edmundintokyo.wordpress.com Edmund in Tokyo

    One more very useful zero-knowledge proof along the same lines: How bad are the opponents’ arguments? This is particularly useful in political situations where there’s a group on the other side with plenty of resources to attack a case. If they’ve had to resort to misleading use of statistics and logic that doesn’t stand up to a bit of thought, there’s a good chance that the case they’re attacking is sound.

  • http://blog.bumblebeelabs.com/?p=310 Bumblebee Labs Blog » Blog Archive » Nov 10th (day 28): The crisis in economics

    [...] a result, economists have developed a simple zero knowledge proof: At the first obvious sign that the other person is not a complete insider of economics, stop [...]

  • http://blog.bumblebeelabs.com/provably-unsolvable-security Bumblebee Labs Blog » Blog Archive » Provably Unsolvable Security

    [...] explainations of infeasibility on a certain degree of faith and deferrel to expert opinion, we use zero knowledge rather than first order [...]

  • Ross Lee Graham, PhD

    You might be interested in Budhist logic as it is not extensional as Western logic developed first by Aristotle. It is intensional (notice the /s/). For basic arguments it uses 5 parts. The first part is a description from an experience intended for interpretation. It is then likened to an immediate experiences, etc. In other words the domain is part of the argument.
    In trying to differentiate the difference between extensional and intensional before you do your own research on the subject concerning domains, consider:
    All men are mortal.
    Socrates is a man.
    Therefore Socrates is mortal.

    That this is an extensional argument is indicated by the use of quantifiers.

    Manness has mortalness.
    Socrates has manness.
    Therefore Socrates has mortalness.

    That this is an intensional argument is indicated by the use of qualities in place of quantifiers.

    I spent some time in India studying Budhist logic translating from Sanskrit and from Tibetan with a group of Tibetans.

  • Ross Lee Graham, PhD

    In computer jargon it would be better to say that the elements of the proof have no designated deference. In a computer we can reference an address. When we dereference the address we are seeing what is at that location (address). If we use the word ‘gravity’ it is like an address, and for it to have meaning to us we must dereference this reference.