eciesrb

Elliptic Curve Integrated Encryption Scheme for secp256k1 in Ruby.

This is a Ruby port of eciespy.

Prerequisite

Make sure you have secp256k1 and openssl installed, if not:

brew install secp256k1 openssl

Then set environment variables:

export C_INCLUDE_PATH=$(brew --prefix secp256k1)/include

Install

Quick Start

# examples/quickstart.rb
require "ecies"

# Generate a secret key
sk = Ecies.generate_key
raw_sk = Ecies.decode_hex(sk.send(:serialize))
raw_pk = sk.pubkey.serialize(compressed: false)

# Encrypt data with the receiver's public key
plaintext = "Hello, World!"
encrypted = Ecies.encrypt(raw_pk, plaintext)

# Decrypt data with the receiver's secret key
decrypted = Ecies.decrypt(raw_sk, encrypted)
puts decrypted  # => "Hello, World!"

Sponsors

Configuration

You can customize the encryption behavior using a Config object:

# examples/config.rb
require "ecies"

Ecies::DEFAULT_CONFIG.is_ephemeral_key_compressed = true   # Use compressed ephemeral public key
Ecies::DEFAULT_CONFIG.is_hkdf_key_compressed = true        # Use compressed key for HKDF
Ecies::DEFAULT_CONFIG.symmetric_nonce_length = 16          # Nonce length for AES-GCM (default: 16)

Configuration Parameters

• is_ephemeral_key_compressed (Boolean): Whether to use compressed format for the ephemeral public key. Default: false
• is_hkdf_key_compressed (Boolean): Whether to use compressed format for HKDF key derivation. Default: false
• symmetric_nonce_length (Integer): The nonce length for AES-GCM encryption. Options: 12, 16. Default: 16

API Reference

encrypt(receiver_pk, data, config = DEFAULT_CONFIG)

Encrypts data using the receiver's public key.

Parameters:

• receiver_pk (String): The receiver's public key (raw bytes, serialized)
• data (String): The plaintext data to encrypt (raw bytes)
• config (Ecies::Config): Optional configuration object

Returns: (String) The encrypted data (ephemeral public key + encrypted data)

decrypt(receiver_sk, data, config = DEFAULT_CONFIG)

Decrypts data using the receiver's secret key.

Parameters:

• receiver_sk (String): The receiver's secret key (raw bytes, serialized)
• data (String): The encrypted data (ephemeral public key + encrypted data)
• config (Ecies::Config): Optional configuration object

Returns: (String) The decrypted plaintext data (raw bytes)

Changelog

See CHANGELOG.md.