bitcore/docs/guide/ecies.md

title: ECIES
description: Uses ECIES symmetric key negotiation from public keys to encrypt arbitrarily long data streams.
---
# ECIES

## Description

Bitcore implements [Elliptic Curve Integrated Encryption Scheme (ECIES)](http://en.wikipedia.org/wiki/Integrated_Encryption_Scheme), which is a public key encryption system that performs bulk encryption on data using a symmetric cipher and a random key.

For more information refer to the [bitcore-ecies](https://github.com/bitpay/bitcore-ecies) github repo.

## Installation

ECIES is implemented as a separate module and you must add it to your dependencies:

For node projects:
```
npm install bitcore-ecies --save
```

For client-side projects:
```
bower install bitcore-ecies --save
```

## Example

```
var bitcore = require('bitcore');
var ECIES = require('bitcore-ecies');

var alicePrivateKey = new bitcore.PrivateKey();
var bobPrivateKey = new bitcore.PrivateKey();

var data = new Buffer('The is a raw data example');

// Encrypt data
var cypher1 = ECIES.privateKey(alicePrivateKey).publicKey(bobPrivateKey.publicKey);
var encrypted = cypher.encrypt(data);

// Decrypt data
var cypher2 = ECIES.privateKey(bobPrivateKey).publicKey(alicePrivateKey.publicKey);
var decrypted = cypher.decrypt(encrypted);

assert(data.toString(), decrypted.toString());
```