Browser IDE without any setup — We are thrilled to introduce the sCrypt Playground, a browser based comprehensive IDE for sCrypt smart contracts. Previously, we have released two IDEs: Desktop IDE: a Visual Studio Code Extension. It comes with advanced language features and is intended for professional development. It requires installing VS Code and the sCrypt…

Previously, we have demonstrated running a fully fledged deep neural network on Bitcoin, where both the input and the model of the machine learning (ML) algorithm are public. In practice, it is often desirable to keep the input or model off chain and thus private, while still ensuring the ML…

Zero-Knowledge Proof (ZKP) is a powerful and foundational cryptographic technique in the blockchain space, due to its potential to address both privacy and scalability. However, its esoteric nature, rooted in abstract and advanced math, places a high barrier to entry to many developers, who are reluctant to learn it despite…

Implement an On-chain Handwritten Digit Classifier — We have implemented a deep neural network for the classification of handwritten digits. The already trained model runs fully on-chain. It is trained offline using the MNIST dataset of handwritten digits. The model takes an image of 28x28 grayscale pixels and outputs a digit from 0 to 9. Introduction to Deep Neural Networks An artificial…

Solve the Back-to-Genesis Problem using recursive SNARKs — This is an implementation of nChain’s solution¹. The Back-to-Genesis Problem Tokens on Bitcoin are typically stored in UTXOs. When a supposed token transaction is received, a user needs a way to efficiently and quickly check its authenticity. …

Proof of a proof of a proof … — We present recursive Zero-Knowledge Proofs (ZKPs), where a proof attests to the validity of another proof. We show its benefits over standard non-recursive ZKPs and showcases its power by applying it to proving Fibonacci sequences. What is a recursive ZKP Suppose Peggy wants to prove to Victor that she will spend next week in a…

A practical step-by-step guide — Zokrates is a toolbox for zkSNARKs, hiding significant complexity inherent to zero-knowledge proofs (ZKP). It provides a python-like higher-level language for developers to code the computational problem they want to prove. We extend it to generate and verify proofs on Bitcoin. Install Zokrates From binary Run the following command to install released binaries: curl…

Solving Blockchain Privacy Dilemma Using Zero Knowledge — We show how to develop games with incomplete information on Bitcoin using Zero Knowledge Proof (ZKP), which is generally regarded unsuitable on a transparent blockchain. We use two games to exemplify the key processes. Paradox There are two categories of games: Complete information games. All players know everything about the game…

ZK Key-Statement Proof — Previously, we have showed how to construct zero-knowledge proof (ZKP) for the following statement, using a technique called ZK Key-Statement Proof (ZKKSP). Basically, it proves not only the prover knows a secret key to a given public key, but also the secret hashes to a given digest, without leaking the…