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ZKPs Reshape The Way We Think About Identityby@technologynews
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ZKPs Reshape The Way We Think About Identity

by Technology News AustraliaNovember 4th, 2023
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It's mind-boggling how these cryptographic marvels are reshaping our understanding of identity and security. The implications are profound, and it’s high time we acknowledge the revolutionary potential of ZKPs. In a world where fraud is not just rampant but practically an industry of its own, ZKPs are nothing short of a godsend. They offer a level of security and privacy that was previously thought to be unattainable.
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Zero-knowledge proofs (ZKPs) and their transformative impact on our concept of identity in a world plagued by digital fraud.


It's mind-boggling how these cryptographic marvels are reshaping our understanding of identity and security. The implications are profound, and it’s high time we acknowledge the revolutionary potential of ZKPs.


In a world where fraud is not just rampant but practically an industry of its own, ZKPs are nothing short of a godsend. They offer a level of security and privacy that was previously thought to be unattainable.


With ZKPs, we can finally reclaim control over our identities and protect ourselves from the countless scams, data breaches, and identity thefts that have become all too common.

An Introduction To ZKP

Zero Knowledge Proofs (ZKPs) are a fascinating concept in the field of cryptography and computer science. They are a type of cryptographic protocol that allows one party (the prover) to prove to another party (the verifier) that a statement is true without revealing any information beyond the validity of the statement itself.


In other words, it allows you to prove knowledge of a secret or the truth of a statement without revealing the secret or any other information about it.


The key idea behind zero-knowledge proofs is to provide convincing evidence of knowledge without revealing the knowledge itself. This has important applications in privacy, security, and authentication.

The Traditional Model of Identity Verification

The traditional model of identity verification is riddled with flaws. From passwords that are easily stolen to personal information that's a goldmine for cybercriminals, it's an antiquated system in desperate need of an upgrade.


Enter ZKPs, which allow us to prove our identity or specific attributes about ourselves without revealing the underlying data. It's like having a superpower that lets us assert our identity without exposing sensitive information.


Imagine never having to give out your Social Security number, credit card details, or any other sensitive personal information to a website, service, or even a government agency!

Finally, the Ultimate Control Over Our Personal Data

With ZKPs, you can provide cryptographic proof that you are who you claim to be, without revealing your actual identity. This is a game-changer folks, as it shifts the power dynamics from institutions to individuals, giving us control over our personal data.

Anonymous & Trustworthy Credentials

ZKPs also enable us to create anonymous yet trustworthy credentials, which can be verified without exposing our identity. This is a dream come true for privacy advocates and those who value their personal data.


We can now participate in transactions and interactions with confidence, knowing that our identity is secure, and our privacy is protected.

Government Adoption - A Shift In Mindset

But, of course, change comes with challenges. The widespread adoption of ZKPs requires not just technological advancements but also a shift in mindset.


Governments, corporations, and even individuals really to start recognizing the value of these extraordinary cryptographic marvels and invest in further research leading to implementation.


The time has come; we need to abandon our old, insecure systems and embrace this new paradigm of identity management.

Defining and Constructing Zero-Knowledge Proof

You know, these zero-knowledge proofs, they sound all fancy and dandy, but let's be real here, how on earth do we even get them? And before we even tackle that conundrum, we haven't even touched the tip of the iceberg!


What does "zero knowledge" even mean, for crying out loud?


So, let's break it down from the ground up. We need to start with the very basics, like defining what in the world we're talking about when we say "proof." I mean, it's not rocket science, a proof system can be thought of as some algorithm Π.


This Π takes a statement, which is just a string x, and another string π, which they call the proof. And what's it gotta do? It's gotta spit out a 1, but only if π is a valid proof that statement x is actually true. Simple, right?


For instance, think about Euclidean geometry. Statements there are just basic geometric facts like "the sum of degrees in a triangle equals 180 degrees," and the proofs, well, they're just those step-by-step derivations from those five postulates. Or how about Zermalo-Frankel + Axiom of Choice (ZFC)?


Statements in that realm are just some highfalutin facts about sets, and the proofs, well, they're just those fancy, highbrow step-by-step derivations from the axioms.


And if you thought that was it, think again! We can cook up all sorts of "theories." You know, where statements are like pairs (x, m), where x is a quadratic residue modulo m, and a proof for x is some number s that's magically related to x in mod m.


Or what about theories where theorems are Hamiltonian graphs? Those are just graphs with n vertices, and they contain a cycle of n edges. The proofs here are just descriptions of that cycle.


But here's the kicker, all these proof systems have one thing in common, they're efficient. Yeah, you heard me right! The whole point of a proof π is to make it a cakewalk to verify that the statement is true. No fuss, no muss, just easy peasy lemon squeezy.


Now, brace yourselves, because to reach the holy grail of zero-knowledge proofs, Goldwasser and Micali had to take proofs to the next level. They went from those static sequences of symbols to some wild, interactive, probabilistic protocols between a prover and a verifier.


And you might think, "What on earth does that mean?" Well, let me break it down for you.


Imagine Alice, who's some kind of tetrachromat, and she can magically tell apart the colors of two identical pieces of plastic. She needs to prove this to Bob, right? So, what do they do? They go all experimental!


Alice turns her back, Bob flips a coin, and with a 50/50 chance, either leaves the pieces as they are or swaps 'em. Alice has to guess whether Bob switched the pieces or not. If she gets it right every time after n rounds, Bob's confidence level goes through the roof. He'll be 1 minus 2 to the power of minus n sure that those pieces are truly different.


And for a more "mathematical" twist, consider this. You've got numbers x and m, and you say x is a quadratic residue modulo m if there's some number s that can make x equal to s squared (mod m).


Now, proving that x is a residue is a piece of cake, but can Alice, even if she's a computational wizard, prove to Bob that x is NOT a residue?


Here's one way to do it. Bob takes some random s from Z* m and flips a coin. If it's heads, he sends s squared (mod m) to Alice; otherwise, he sends x times s squared (mod m).


Alice shoots back with a 0 if Bob sent a quadratic residue, and a 1 if he didn't. And the magic is, if x is a non-residue, then x times s squared must also be a non-residue, and that's like a mathematical fact, folks!


So no matter what Alice does, her chances of guessing right are just 1/2. So, if she keeps nailing it, Bob's confidence level will keep soaring to the sky, going 1 minus 2 to the power of minus n.

Boom!

The Cryptography & Mathematics Behind Zero-Knowledge Proofs

Alright, strap in folks! We're diving headfirst into the wild world of mathematics, and specifically, zero-knowledge proofs. Buckle up because we're about to take a rollercoaster ride through number theory, modular arithmetic, and group theory. Are you ready? Let's go!

Number Theory

First things first, let's talk about numbers. Integers, rational numbers, real numbers – they're all in the mix, and they're as diverse as they come. Integers are like the wild bunch, including the positives, the negatives, and even that mysterious zero.


You've got numbers like -3, -2, -1, 0, 1, 2, 3... you get the idea. For example, 5 is in this gang.


Now, rational numbers, they're the fractions of the bunch. Any number that can be written as a fraction with an integer numerator and denominator (as long as that denominator isn't playing zero) is a rational number. So, 1/2, 2/3, 7/1 – they're all in this club.


But hold on, the real numbers, they're the wildest ones of them all. They've got the rational folks in there, but they're not stopping there. Nope, they're bringing in the irrational ones, those weirdos that can't be expressed as simple fractions and have never-ending, non-repeating decimal parts.


3.14159 (pi), the square root of 2, 2, -1 – they're all crashing this party.

Modular Arithmetic

Now, let's talk about modular arithmetic. Think of it as math with a twist. It's like playing with numbers on a clock – they wrap around after hitting a certain value. When we say something like 25 mod 3, we're basically saying, "Hey, what's the remainder when we divide 25 by 3?"


In this case, it's 1. Yeah, 25 divided by 3 leaves us with 1 in the leftovers department.


And guess what? We're keeping things positive here. That remainder is always a non-negative number; no room for negativity in this club.

Modular Arithmetic in zk-SNARKs

Now, we're getting into the nitty-gritty of cryptography and zk-SNARKs. In zk-SNARKs, we're using modular arithmetic to create some kind of secret handshake.


We're making an arithmetic circuit within a finite field. Picture this: you've got some computation like x * y = z, but we're doing it within the bounds of a finite field defined by a prime number, let's say p = 13.


So, if x = 7 and y = 8, we're doing (7 * 8) mod 13, which equals 9. It's like a secret math language, making sure everything stays within manageable limits. It adds an extra layer of mystery to our calculations, which is gold in the world of cryptography.


In zk-SNARKs, the prover's showing off their skills, proving they did the math correctly without revealing their secret values. The verifier gets to check the proof without doing the math themselves and without learning anything juicy about those values. Pretty cool, right?

Practice Questions

If you're feeling brave, give these questions a shot:


  1. Calculate 18 mod 7


  2. Calculate 30 mod 5


  3. Calculate 21 mod 6


  4. In a finite field defined by the prime p = 17, do the following calculations: a. (8 * 9) mod 17 b. (15 + 7) mod 17 c. (11 - 4) mod 17


  5. Imagine you've got a computation x * y = z in a finite field with prime p = 19, and z = 5.


    Can you figure out possible values for x and y without spilling the beans?

Group Theory

Now, we're diving into group theory. Imagine a group as a gang of numbers with their own special operation. They've got four rules to follow: closure, associativity, identity element, and inverse element.


Think of it as a secret club where everything has to go according to plan. Subgroups are like mini-clubs within the bigger gang. They've got their own rules to follow, but they're still part of the larger gang. It's like a gang within a gang.

Homomorphisms and Isomorphisms

Homomorphisms are like secret agents between gangs. They make sure the gang operations are still working when they go from one gang to another. It's like they're translating the secret handshake.


Isomorphisms are the big deal. When two gangs are isomorphic, it's like they're long-lost twins. They're essentially the same gang but described differently. It's like saying that integers and even integers are two sides of the same coin.

Fields

Fields are the VIP club of mathematics. They've got addition and multiplication, and they've got rules like closure, associativity, commutativity, and more. Every number (except for zero) has a special inverse in this club. Real numbers and integers mod a prime number are some examples of fields.


Oh, and finite fields, they're exclusive clubs with a limited guest list. There's always a special generator who can create all the elements in the club by raising different powers. It's like magic math!

Polynomials and Roots

Now, we're talking polynomials. They're like equations on steroids. A single equation between polynomials can represent a gazillion equations between numbers. It's like the math version of a superpower.


Roots are like the secret codes of polynomials. If you find the right root, you can unlock the secrets hidden in the polynomial. And when one polynomial divides another, it's like a big brother watching over the little one.

A Formal Definition From All This Nonsense!

Let's dive into this formal definition nonsense, and I'll break it down for you in plain English.

So, they're talking about this thing called a "probabilistic proof" for some set L with 0s and 1s. Sounds complicated, right? Well, it is! But let's go through it.


First, there are two main characters in this story, P and V. P is like the guy trying to prove something, and V is the one who's there to check if P is telling the truth. They're like the dynamic duo of algorithms.


Now, there are two key criteria here:


  1. Completeness: If something is in L, and P and V chat about it, V better say "Accept" with a high chance (at least 90%). Otherwise, P's not doing a good job proving.


  2. Soundness: If something is not in L, no matter what kind of tricky algorithm P∗ is, when P∗ and V discuss it, V should only "Accept" with a tiny chance (maximum 10%). If V keeps accepting, it means something fishy is going on.


And don't you worry, they're not too fussy about P being super-efficient. It might be slow and clunky, but as long as it gets the job done, it's all good. On the flip side, even if P is devious and inefficient, the soundness rule still applies. So no tricks, P!


Now, they start yammering about efficient provers and NP-type proof systems, but let's not get bogged down in the details. Just know that they want P to do its job without wasting too much time.


Oh, and this bit about strategies? It's like when you're playing a game, and you're not sure if the other players are playing fair. They're saying, "Hey, we don't want to rely on anyone's good intentions." They're ready for anything, even if someone's being sneaky.


So, in a nutshell, they're looking for proof that's both solid and efficient, and they're not putting all their trust in anyone. Play nice, everyone, or things could get messy!

Amplifying Zero-Knowledge Proofs

Let's talk about this whole amplifying zero-knowledge proofs thing for a bit. So, you know, we've got this idea of running them n times one after the other, but why stop there? Why not just run those n copies in parallel and see what happens, right?


But, of course, it's not like it's a walk in the park to guarantee that we still get that sweet error reduction to 2^-n. Like, who knows, maybe we luck out in the cases we care about, or maybe not.


And then, oh boy, zero knowledge, it's like the holy grail of this whole cryptography game, right? Well, you see, it's not always guaranteed to stay intact. I mean, come on, we're not always sure if zero knowledge is still a thing when we're dealing with the ZK-Ham protocol.


It's like this huge question mark hanging over our heads.

Stuck in the Dark Ages!!, Well, for Ages!!

You know what really grinds my gears? The fact that so many people out there are still stuck in the dark ages when it comes to thinking about identity.


It's like we're living in a time warp, unable to embrace the incredible potential of Zero-Knowledge Proofs (ZKPs), and how they're reshaping the way we perceive and understand identity.


I mean, seriously, ZKPs are nothing short of a game-changer. They're a technological marvel that can revolutionize the way we interact with the digital world.


With ZKPs, we can finally break free from the chains of traditional identity systems that are plagued by privacy breaches, identity theft, and centralized control.


Personally, I don’t understand why so many folks are still clinging to outdated notions of identity verification. We're talking about a paradigm shift here! ZKPs allow individuals to prove that they possess certain credentials or attributes without revealing any personal information.


It's like having your cake and eating it too! You can prove you're over 18 without disclosing your birthdate. You can verify your educational qualifications without revealing your entire academic history. It's a privacy advocate's dream come true!


And let's not forget about the centralized authorities that have had an iron grip on our identities for far too long. ZKPs give us the power to decentralize identity verification, removing the need for Big Brother to oversee our every digital move. It's about time we took control of our own data and who gets to access it.


ZKPs are not some distant futuristic concept. They're here, they're now, and they're ready to reshape the way we think about identity.


It's time to break free from the shackles of archaic identity systems and embrace the potential of ZKPs to create a more secure, private, and user-centric digital world.


So, if you're still stuck in the past, clinging to outdated notions of identity, it's time to wake up and smell the cryptographic roses. ZKPs are here to stay, and they're reshaping the way we think about identity, whether you like it or not!


See, this whole zero-knowledge proof thing, it's like taking proofs to a whole new level of mind-boggling complexity and secrecy, and it's mind-blowing!


So, the next time you hear someone talk about zero-knowledge proofs, you'll know it's not just some walk in the park. It's a journey into the depths of mathematical secrecy and computational wizardry!


Anyways, fraud, in all its forms, has been a persistent and insidious threat to our digital lives. It's time we as a society, as individuals, and as businesses, fought back and took a stand against this rampant menace.


And if there's one tool in our arsenal that stands out as a potent weapon in this battle, it's Zero-Knowledge Proofs (ZKPs).


Let's take the example of online authentication. In the current system, when you log in to a website or app, you typically provide a username and password.


These are "secrets" you know, and you share them with the service to prove your identity. But here's the catch: if that service gets breached, your username and password could be exposed to malicious actors.


Fraudsters would then use this information to impersonate you, steal your data, or carry out fraudulent activities.


Now, imagine a world where instead of sharing your actual password, you use a Zero-Knowledge Proof to prove that you know your password without revealing it.


The service you're logging into would only get confirmation that you have the correct password, but they wouldn't actually see what it is. This means that even if the service gets hacked, your password remains safe.


But the power of ZKPs doesn't stop at authentication. They can be applied to financial transactions, medical records, and a multitude of other scenarios where privacy and security are paramount.


The potential benefits of ZKPs are immense, but there's a catch. Widespread adoption and deployment of ZKPs require a shift in how we approach digital security and a significant investment in research and development.


It's not a silver bullet solution, and it won't be implemented overnight. But we must recognize that the stakes are high. Deployable fraud costs individuals and businesses billions of dollars every year, and the emotional toll it takes on victims is immeasurable.


These cryptographic tools empower us to regain control over our identities, protect our personal data, and ultimately reshape the way we think about identity in the digital age. It's time to harness the potential of ZKPs and leave digital fraud in the past where it belongs.