Encryption Request Flow

Overview

This document outlines the complete flow of the encryption request process using Cofhejs, a TypeScript library designed to help users encrypt data for private computation with smart contracts. Understanding this process is essential for developers who want to enable their users to interact with privacy-preserving smart contracts using encrypted inputs.

Key Components

Component	Description
dApp	The decentralized application that interacts with the user and the contracts
Cofhejs	TypeScript package designed for seamless interaction Fhenix's co-processor
Threshold Network	(When applicable) Handles secure decryption operations

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Flow Diagram

The following diagram illustrates the complete flow of an Encryption request in the CoFHE ecosystem: Figure 1: End-to-end flow of an Encryption request through the CoFHE system components

Step-by-Step Flow

1. Install, include and initialize Cofhejs in your project (full details here)

   npm install cofhejs

   const { cofhejs, FheTypes, Encryptable } = require("cofhejs/node");

2. Data preparation
   The data is encrypted locally using the encrypt function. Under the hood, encrypt encrypts the data using the TFHE library and create a zkPoK to prove the encryption is correct.

3. Encryption verification
   The zkPoK is verified using the verify function.
   This verification process ensures that the ciphertext was generated correctly—that it represents a valid encryption of a known plaintext—and that the data has not been tampered with. Upon successful verification, the encrypted data is stored in the Data Availability (DA) layer.

   The function returns a value handle that can be used to reference the encrypted data later, along with a signature.

4. Using the encrypted data
   The user can send the value handle to the contract as an encrypted input. This handle represents the ciphertext stored in the DA layer and allows the contract to reference the encrypted value

Note: Read more about the implementation details here