# web3-encrypt

> Provides methods for symmetric encryption/decryption using Ethereum addresses.

Latest version **1.0.1** (published 2019-03-21) · GPL-3.0-only license · 0 weekly downloads

> **Deprecated.** This package is deprecated.

## Install

```sh
npm install web3-encrypt
pnpm add web3-encrypt
yarn add web3-encrypt
bun add web3-encrypt
```

## Health

**Score 10/100 (F)** — status: deprecated.

Negative: deprecated.

## Facts

| | |
|---|---|
| Version | 1.0.1 |
| Published | 2019-03-21 |
| First published | 2019-03-08 |
| Weekly downloads | 0 |
| License | GPL-3.0-only |
| TypeScript types | none |
| Module format | CommonJS |
| Dependencies | 3 |
| Unpacked size | 42.2 KB |
| Known vulnerabilities | 0 |
| Install scripts | no |
| GitHub stars | 11 |
| Author | Dillon Kellar |
| Maintainers | d1ll0n |

## Links

- npm: https://www.npmjs.com/package/web3-encrypt
- Repository: https://github.com/d1ll0n/web3-encrypt
- Issues: https://github.com/d1ll0n/web3-encrypt/issues
- npm.io page: https://npm.io/package/web3-encrypt

## Dependencies (3)

- [web3](https://npm.io/package/web3.md) ^1.0.0-beta.48
- [scrypt](https://npm.io/package/scrypt.md) ^6.0.3
- [ethereumjs-util](https://npm.io/package/ethereumjs-util.md) ^6.1.0

## Recent versions

- 1.0.1 (latest) — 2019-03-21
- 1.0.0 — 2019-03-08

## README

# web3-encrypt
Provides methods for symmetric encryption/decryption using Ethereum addresses.

Usually when we use a web3 provider on a browser, such as MetaMask, Fortmatic, Bitski, etc., we do not have access to the private keys of accounts. Since we may want some secure mechanism for a user to store data on a server and retrieve it later, we need a workaround. 

The method employed in this library is to take some arbitrary salt which the client can be assumed to always have access to, create a signature of that salt using the web3 provider, then use that signature as a symmetric key to encrypt some data. So long as the signature is never revealed, this should be a secure encryption method when we do not have access to private keys.

## Installation

### Node

```bash
npm install web3-encrypt
```

## Usage

```js
const { 
  Web3Encryption, web3Encrypt, web3Decrypt, constructWeb3 
} = require('web3-encrypt')

/*
constructWeb3 takes an http provider url and returns a web3 instance
but you can provide your own Web3 object to Web3Encryption
*/

const web3 = constructWeb3('https://mainnet.infura.io/v3');
const account = web3.eth.accounts.create();
const message = 'hello crypto boys'
const salt = 'special-salt'

async function testCryptoFunctions() {
    const cipher = await web3Encrypt(web3, account, message, salt)
    console.log(`cipher from encrypt function: ${cipher}`)
    const decipher = await web3Decrypt(web3, account, cipher, salt)
    console.log(`deciphered message: ${decipher}`)
    console.log(`deciphered message ${decipher == message ? 'matches' : 'does not match'} original`)
}   
testCryptoFunctions()
`
> cipher from encrypt function: f7b5efbe6d7ac17d89032ba428acfc89f10cf5fc10305732ee1b741f1f73b4a2
> deciphered message: hello crypto boys
> deciphered message matches original
`

async function testCryptoObject() {
    const w3crypto = new Web3Encryption(web3, account, salt)
    const cipher = await w3crypto.encrypt(message)
    console.log(`cipher from encrypt function: ${cipher}`)
    const decipher = await w3crypto.decrypt(cipher)
    console.log(`deciphered message: ${decipher}`)
    console.log(`deciphered message ${decipher == message ? 'matches' : 'does not match'} original`)
}
testCryptoObject()
`
> cipher from encrypt function: f7b5efbe6d7ac17d89032ba428acfc89f10cf5fc10305732ee1b741f1f73b4a2
> deciphered message: hello crypto boys
> deciphered message matches original
`
```

# web3Encrypt(web3, account, message, salt)

**Params**

- web3 `object` - Instance of a Web3 object
- account `object` - Instance of an Ethereum account, such as from web3.eth.accounts
- message `string` - The message to encrypt
- salt `string` - The salt input which is signed by the web3 account

**Returns**: `Promise<string>` Cipher text after encryption

# web3Decrypt(web3, account, cipher, salt)

**Params**

- web3 `object` - Instance of a Web3 object
- account `object` - Instance of an Ethereum account, such as from web3.eth.accounts
- cipher `string` - The ciphertext to decrypt
- salt `string` - The salt input which is signed by the web3 account

**Returns**: `Promise<string>` Decrypted message

# Web3Encryption.encrypt(message, options)
Calls web3Decrypt() using the Web3Encryption instance properties or the overridden options
**Params**

- message `string` - The message to encrypt
- options `object` - Optional properties 
    - salt `string` - The salt input which is signed by the web3 account
    - web3 `object` - Instance of a Web3 object
    - account `object` - Instance of an Ethereum account, such as from web3.eth.accounts

**Returns**: `Promise<string>` Cipher text after encryption

# Web3Encryption.decrypt(cipher, options)
Calls web3Decrypt() using the Web3Encryption instance properties or the overridden options
**Params**

- cipher `string` - The ciphertext to decrypt
- options `object` - Optional properties 
    - salt `string` - The salt input which is signed by the web3 account
    - web3 `object` - Instance of a Web3 object
    - account `object` - Instance of an Ethereum account, such as from web3.eth.accounts

**Returns**: `Promise<string>` Cipher text after encryption

---
_Source: https://npm.io/package/web3-encrypt · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._