Getting Snarky: A Brief Look At zk-SNARKs


Estimated reading time: 3 minutes, 5 seconds

The word “Snarky” is used to describe speech with a specific emotional tone, typically a form of sarcasm informed by cheekiness and mild, playful irreverence or impudence.”

Conversely, while the word “snark” is prevalent in its name, zk-SNARK is an important new technology that’s neither mild nor cheeky.

So, what exactly is zk-SNARK?

First, let’s start with what the acronym stands for, which is “Zero-Knowledge, Succinct, Non-Interactive Argument of Knowledge.”

Essentially, zk-Snark is proof construction that allows an individual to prove possession of certain information; “e.g. a secret key, without revealing that information, and without any interaction between the prover and verifier.”

As the full name implies, zk-Snarks are what’s known as a “Zero-knowledge” proof. These types of proofs allow for a party to verify that a certain statement is true, without having to provide further detail beyond the validity of the initial statement itself.

Here’s an example of a real-world situation where zk-SNARK would come in handy:

Let’s say a person wants to live a retirement community that requires residents to be at least 55 years of age. However, though they meet the requirement, this individual doesn’t want to share their age. With zk-SNARK proofs, the individual could, hypothetically, verify that they are over 55, without having to give their actual age.

Investopedia author Jake Frankfield does an excellent job highlighting the difference between traditional proofs and zero-knowledge proofs:

“For an example of a traditional proof, consider a password used to access an online network. The user submits the password, and the network itself checks the contents of the password to verify that it is correct. In order to do this, the network must also have access to the contents of the password. A zero-knowledge proof version of this situation would involve the user demonstrating to the network (via mathematical proof) that he or she has the correct password without actually revealing the password itself.”

The example Frankfield provided demonstrates how zero-knowledge proofs can help keep information more secure. In his example, since the users aren’t actually revealing their password, it can’t be stolen and potentially misused.

Zk-SNARKs and Zcash

At present, as far as use cases go, zk-SNARK is most commonly associated with the cryptocurrency known as Zcash (ZEC) – an altcoin that was designed to provide users with enhanced privacy.

With cryptocurrencies, like bitcoin, transactions can be viewed on a public blockchain, along with info such as the user’s address and the amount of crypto being transferred. Using zk-SNARKs, Zcash’s Zerocash protocol allows folks to transfer tokens without revealing their user address or the amount of funds being transacted.

Keeping Information Private

Beyond cryptocurrency, zk-SNARK provides companies with an opportunity to fully utilize blockchain tech, without fear of sharing potentially vital information.

One of the issues with blockchains is that all node operators can access information on the platform. This means that if rival companies decided to store information on the same blockchain, they could view each other’s data.

Zk-Snarks gives business the option to store only the proof of the transactions, without providing any detailed info, so companies don’t have to worry about competitors getting their data.

As Forbes writer Samantha Rodocchia explains:

“These proofs are allowing blockchain companies to build smarter, automated systems that can attest to certain facts without revealing the data behind those facts.

That’s important because while greater transparency has long been the goal of many blockchain advocates, transparency has its limits. Both companies and individuals have reasons to keep sensitive information private, while still reaping the benefits of a decentralized blockchain network.

And zk-SNARKs are helping to do just that.”

Want to know more about Zk-Snarks? Check out this video!