Zcash — Inversed

Introduction

The birth of the internet promised openness. A space where ideas could flow freely and securely.

Over time, that promise eroded. Disregarded in favour of surveillance and centralization.

The Zcash Foundation originated to counter that shift. Building tools for privacy and financial agency, in a world increasingly centralized.

In 2023, the Foundation set out to understand how private programmability might exist on their blockchain.

The challenge

The Zcash blockchain is privacy-first by design. That privacy introduces friction to extending the protocol’s capabilities. Most smart contract platforms are built with transparency at their core. Therefore, integrating programmability without compromising privacy means rethinking assumptions about cryptography from first-principles.

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The Foundation wanted to figure out how to enable applications to run privately on-chain, in a manner that would allow for programmable logic to be executed without revealing inputs, outputs, or user identities. No shortcuts and no leaks.

Why it matters

Society deserves systems it can trust.

Building a high-trust future demands secure computation. Not just for transactions, but for entire systems. This project reflects that shift toward systems operating privately by design.

Cryptography must align them consciously.

Using cryptography to shape systems that power openness through privacy, without compromise, speaks directly to our purpose here at Inversed.

Our approach

Inversed partnered with the Zcash Foundation to explore, design, and implement a cryptographic framework that brings private programmability to life. Our solution was grounded in zk-SNARKs– a form of zero-knowledge proof that lets systems prove that something is correct without sharing the underlying data. Thereby keeping transactions private yet verifiable.

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Embedding zk-SNARK-based private function evaluation into Zcash’s protocol, enabled developers to write on-chain contracts that process data privately. Zcash applications are now able to execute logic without revealing underlying details; preserving utility and anonymity.

implementation

Architecting trust from first principles

Actually delivering on the Foundation’s goals required a combination of applied cryptography, systems integration, and deep-protocol level understanding. This wasn’t just an engineering effort, it was the establishment of cryptographic architecture for a new class of secure, decentralized applications.

A curved timeline graph illustrating the increasing impact and technical maturity of a cryptographic solution for Zcash. It includes five milestones: Define constraints, Design the architecture, Build the cryptography, Real-world tests, and Functional rollout. Each milestone is marked by a red dot along the curve. The background features a 3D grid for depth, and the lower section lists four key actions taken to achieve the goal, such as developing novel cryptographic protocols and leveraging Rust for secure components.

To get there, we had to:

Develop novel cryptographic protocols for private function evaluation.
Integrate with Zcash’s Sapling protocol and cryptographic primitives.
Leverage Rust to build performant, secure components.
Explore optimizations for developer ergonomics and scalability.

Results & impact

While still early in terms of its adoption curve, we established critical foundations for private programmability on the Zcash network. Ultimately proving the feasibility of building privacy-preserving applications at scale, which has also surfaced key insights for future R&D in this domain.

Implications

The work done itself has expanded the realm of possibilities for privacy-focused blockchain ecosystems. For the Zcash Foundation, they’ve opened up a new frontier that moves closer to the vision for digital freedom. For Inversed, it reflects our belief that the best security is quiet, built into systems themselves– not bolted on as a mere afterthought.

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Through private programmability, the door is opening to a world where smart contracts run securely without making privacy the price of entry.