# zkSNARKs for scaling

## Intro

We have a bunch of projects that try to use snarks to scale eth. We estimate we can get between 100 and 500 transactions per second on ethereum today. We can even approch 33000 transactions per second for non custodial dapps.

its important to note that this is not just for transactions. We can build any kind of dapp that runs in the EVM in a snark and get similar scaling benifits.

https://github.com/barryWhiteHat/roll_up_token is a good description of how these things works.

Ignis implementation by Matter Labs: https://github.com/matter-labs/matter-network
Aggregate zkSNARK transactions (like roll_up) https://github.com/HarryR/ethsnarks-snasma/

join us https://t.me/ethdenver_snarks4scaling

## General Mentorship

Following on from ethdenver we are starting to make a nice group of snark mentors. This includes the authors of circom, ethsnarks and the matter team. As well as partipents and winners from ethdenver.

## Where to ask for help

[Come and talk to us in Telegram group @ethdenver_snarks4scaling ](https://t.me/ethdenver_snarks4scaling )
[Facebook public group: Zero Knowledge](https://www.facebook.com/groups/800441673459620/)

## Tools

### [ethsnarks](https://github.com/HarryR/ethsnarks)

[Ethsnarks](https://github.com/HarryR/ethsnarks) is a SDK for writing Ethereum compatible zkSNARK circuits in C++ using the [libsnark](https://github.com/scipr-lab/libsnark/) library. It includes support for the following crypto primitives with matching Python, Solidity and C++ implementations:

* Low-cost verification (~450k Gas base cost)
* Low-constraint Merkle Tree
* MiMC cipher and hash
* Baby JubJub elliptic curve
* EdDSA signatures
* Pedersen hashing

Main GitHub repository: https://github.com/HarryR/ethsnarks

Rudimentary knowledge of C++ and CMake is required to build circuits. Reading the source code and example projects is the best way to get hands-on.

#### Examples

These example projects can be used as templates and include Truffle support with Travis continuous-integration, or demonstrate key concepts like EdDSA signatures.

* https://github.com/HarryR/ethsnarks-miximus - Anonymous coin mixer for Ethereum
* https://github.com/HarryR/ethsnarks-hashpreimage - Hash pre-image zero-knowledge commitment example
* https://github.com/HarryR/ethsnarks-snasma - Batch transaction processing example

#### Community:
* https://gitter.im/ethsnarks/Lobby (text chat, ping `@HarryR`)
* https://meet.jit.si/ethsnarks (video/audio conference)
* https://gitter.im/barrywhitehat/roll_up (related people/projects)

Harry (the ethsnarks maintainer) is available on Telegram, [Gitter](https://gitter.im/ethsnarks/Lobby) and can do [video calls](https://meet.jit.si/ethsnarks) (in GMT timezone, 7hr behind Denver). Is willing to help with all aspects, even if not specifically related to ethsnarks.

### [circom](https://github.com/iden3/circom)

[circom](https://github.com/iden3/circom) is a DSL language where you can design circuits to create zeroKnowledge proof.

Those proofs can be generated/verified in the browser or in node JS via the [snarkjs](https://github.com/iden3/snarkjs) library

[snarkjs](https://github.com/iden3/snarkjs) also allows to create a smart contract to verify the zero knowledge proofs from a smart contract.

[circom](https://github.com/iden3/circom) Comes together with [circomlib](https://github.com/iden3/circomlib) In this library, you can find some basic components that you can use in your project. This includes.

#### Examples

The best way to get started to create a zero knowlage proof circuit is this [tutorial](https://github.com/iden3/circom/blob/master/TUTORIAL.md)

There is a roll_up specific tutorial https://github.com/GuthL/roll_up_circom_tutorial

iden3 telegram group: https://t.me/iden3io

### [Bellman](https://github.com/matter-labs/bellman)

zkSNARK library for community with Ethereum's BN256 support

[Bellman](https://github.com/matter-labs/bellman) is a fork of the original implementation by Sean Bowe from Zcash that is now maintained with code comments, extension for Ethereum compatible curve (and more curves in a future) and other proof systems (GM17, SONIC). It should be used with a gadget library [sapling-crypto](https://github.com/matter-labs/sapling-crypto) to produce actual circuits. The best part of Bellman is convenience and speed simultaneously - witness calculation is defined "in-place", and Rust is as fast as C++.

#### Examples

* [Edcon2019 material (code example + workshop record)](https://github.com/matter-labs/Edcon2019_material)
Simple circuit that will be used for an EDCON 2019 webcast

* [Implementation of non-inclusion proof for Plasma Cash](https://github.com/matter-labs/PlasmaCashHistorySnark-iOS)

* [Original code from ETHSignapore that gave a start for Ignis](https://github.com/matter-labs/plasma_winter)
The Plasma Winter repository also contains verifying contract and utils that can export verification keys as Solidity smart-contracts.

* Igor’s example: https://github.com/snjax/bellman_cube

## Links
https://github.com/barryWhiteHat/roll_up_token
[barryWhitehat devcon presentation](https://www.youtube.com/watch?v=lv6iK9qezBY)
[telegram group: ethdenver_snarks4scaling](https://t.me/ethdenver_snarks4scaling)
[gitter](https://gitter.im/barrywhitehat/roll_up)
https://blog.decentriq.ch/zk-snarks-primer-part-one/

### Educational links:

[Snarks for mixing, signaling and scaling
by Barry Whitehat](https://slideslive.com/38911801/snarks-for-mixing-signaling-and-scaling)
[A good article which gives an overview of the current state of things
](https://medium.com/qed-it/diving-into-the-snarks-setup-phase-b7660242a0d7)