Privacy

Ethereum blockchain is transparent to the core. That’s why it may seem contradictory, that an open-ledger, open-source technology like it would attempt to disguise itself with anonymous transactions. However, it’s more like a data security in order of protection the anonymity of cryptocurrency users – all while maintaining the integrity of public ledger.

The key implemented privacy solutions in Ethereum until now are mixing and zero-knowledge based approaches.

Overview 

Privacy in Cryptocurrencies  – overview, approaches and zero-knowledge proofs
How Is Blockchain Verifiable by the Public and yet Anonymous?difference between the levels of anonymity on private and public blockchains
The State of Privacy on Ethereum  – article that briefly examining the demands for practical privacy on public blockchains and to discussing at a high level the tradeoffs of implementing privacy solutions
Privacy on Ethereum  – summary of used technologies and working teams
Zero Knowledge Proof  – explained like you are 5
Zero Knowledge Proofs  – an illustrated primer
A Cambrian Explosion of Crypto Proofs it surveys the expanding crypto-verse of proof systems and the role of symmetric STARKs within
Zero Knowledge Proofs & Ethereum  – what it is and how it works, use cases and limitations, tools and projects
Emerging Use Cases For ZKPs in 2019 it was a big year in the zero knowledge research space
Comparing General Purpose zk-SNARKs  – comparison of the most recent constructs
Bringing Privacy to Non-Fungible Tokens  – proof-of-concept for building a tightly integrated zero-knowledge proof using the ZoKrates language and toolchain
Building the first-ever zero-knowledge DAO proof-of-concept  – design considerations and potential implications
Write your first zk-snark  – using Iden3’s circom and snarkjs libraries
SLONK  – simple universal SNARK
Complete Knowledge proofs  – allow a user to demonstrate that they really have control of secret data, and the data isn’t shackled by SGX or MPC
Transparent SNARKs from DARK compilers  – transparent zk-SNARK that has both a practical prover time as well as asymptotically logarithmic proof size and verification time

Mixers 

State of the Mixers  – a survey of active mixer efforts on Ethereum, including history, context and benchmarks

Tornado  – allows users to mix their Ethereum transactions in a non-custodial, trustless and serverless way
Hopper  – open-source mixer, that allows the private transfer of value from one Ethereum account to another, via an iOS client
Heiswap  – mixer that allows users to ‘wash’ their ETH in a confidential manner (i.e. who the sender sends money to is hidden)
MicroMix  – ETH and ERC20 token mixer
Salad  – coin mixer built on Enigma

Other tools and implementations

AZTEC Protocol  – zero-knowledge privacy protocol
Nightfall  – protocols for private transactions on the Ethereum public blockchain using zk-SNARKs, developed by EY
ZoKrates  – toolbox for zkSNARKS on Ethereum
libSTARK  – C++ library for ZK-STARK systems
ZEXE  – Rust library for decentralized private computation
Go-SNARK  – zkSNARK library implementation in Go
snarkjs  – zkSNARK implementation in JavaScript
genSTARK  – library for generating zk-STARKs
websnark  – zkSNARK proof generator written in native Web Assembly
circom  – circuit compiler for zkSNARKs
Semaphore  – zero-knowledge signaling
ZeroPool  – anonymous multi-asset pool
Private Auction  – private blind auctions using Aztec and Torus
Franklin  – ZK Rollup – commit-chain driven by SNARKs
OpenZKP  – fully open-source Rust implementation of zero-knowledge proofs
ZK Sync  – trustless scaling and privacy solution for Ethereum based on ZK Rollup
Zether  – private payment system for Ethereum-based blockchains, developed by JP Morgan

Resources 

Zero Knowledge  – podcast made for developers and people looking to learn about ZK tech
Awesome zero knowledge proofs  – curated list of awesome things related to learning zero knowledge proofs
Privacy collection on Kauri  – learn privacy in blockchain, curated set of articles and guides, an entry point for beginners who wish to learn about all things privacy in blockchain
Eth mixer list  – curated list of awesome things related to learning zero knowledge proofs