index.md

title
AES-GCM-SIV

AES-GCM-SIV

.NET Core 3.0 implementation of AES-GCM-SIV nonce misuse-resistant authenticated encryption, defined in draft-irtf-cfrg-gcmsiv-08. Fastest available authenticated encryption library for .NET, with the encryption/decryption rate of roughly 8 Gbps/core. Implemented using .NET Core 3.0 platform intrinsics.

Usage

// Plaintext to encrypt.
var plaintext = "I'm cooking MC's like a pound of bacon";

// Create a 32-byte key.
var key = new byte[32];
RandomNumberGenerator.Fill(key);

// Create a 12-byte nonce.
var nonce = new byte[12];
RandomNumberGenerator.Fill(nonce);

// Create a new AesGcmSiv instance. It implements the IDisposable
// interface, so it's best to create it inside using statement.
using (var siv = new AesGcmSiv(key))
{
  // If the message is string, convert it to byte array first.
  var bytes = Encoding.UTF8.GetBytes(plaintext);

  // Encrypt the message.
  var ciphertext = new byte[bytes.Length];
  var tag = new byte[16];
  siv.Encrypt(nonce, bytes, ciphertext, tag);

  // To decrypt the message, call the Decrypt method with the
  // ciphertext and the same nonce that you generated previously.
  siv.Decrypt(nonce, ciphertext, tag, bytes);

  // If the message was originally string,
  // convert if from byte array to string.
  plaintext = Encoding.UTF8.GetString(bytes);

  // Print the decrypted message to the standard output.
  Console.WriteLine(plaintext);
}

Installation

> dotnet add package AES-GCM-SIV --version 0.3.2

Acknowledgements

This implementation is based on the C intrinsics code written by Shay Gueron.

Resources

AES-GCM-SIV: Nonce Misuse-Resistant Authenticated Encryption
AES-GCM-SIV: Specification and Analysis
Webpage for the AES-GCM-SIV Mode of Operation
AES-GCM-SIV implementations (128 and 256 bit)
Go implementation
Java implementation
AES-GCM-SIV (Adam Langley)
Towards A Safer Footgun (Coda Hale)

Performance (Windows)

BenchmarkDotNet=v0.11.1, OS=Windows 10.0.17134.345 (1803/April2018Update/Redstone4)
Intel Core i7-4800MQ CPU 2.70GHz (Max: 2.69GHz) (Haswell), 1 CPU, 8 logical and 4 physical cores
Frequency=2630636 Hz, Resolution=380.1362 ns, Timer=TSC
.NET Core SDK=3.0.100-alpha1-009638
  [Host] : .NET Core 3.0.0-preview1-27003-04 (CoreCLR 4.6.27002.04, CoreFX 4.6.27002.03), 64bit RyuJIT

Method	Categories	Size	Mean	Error	StdDev	Scaled
AES-GCM	Encryption	128	306.2 ns	0.5986 ns	0.5307 ns	1.00
AES-GCM-SIV	Encryption	128	287.7 ns	3.6306 ns	3.2185 ns	0.94
AES-GCM	Decryption	128	311.7 ns	0.2751 ns	0.2438 ns	1.00
AES-GCM-SIV	Decryption	128	329.5 ns	2.6803 ns	2.2382 ns	1.06
AES-GCM	Encryption	1024	681.1 ns	1.5380 ns	1.3634 ns	1.00
AES-GCM-SIV	Encryption	1024	663.0 ns	2.6639 ns	2.4918 ns	0.97
AES-GCM	Decryption	1024	681.0 ns	0.7810 ns	0.6923 ns	1.00
AES-GCM-SIV	Decryption	1024	715.3 ns	1.3908 ns	1.3009 ns	1.05
AES-GCM	Encryption	4096	1,984.3 ns	6.5387 ns	5.4601 ns	1.00
AES-GCM-SIV	Encryption	4096	1,877.8 ns	0.5862 ns	0.5196 ns	0.95
AES-GCM	Decryption	4096	1,988.5 ns	1.0060 ns	0.8401 ns	1.00
AES-GCM-SIV	Decryption	4096	1,882.5 ns	7.0526 ns	6.5970 ns	0.95
AES-GCM	Encryption	8192	3,754.4 ns	84.4706 ns	79.0138 ns	1.00
AES-GCM-SIV	Encryption	8192	3,503.4 ns	2.5222 ns	2.1061 ns	0.93
AES-GCM	Decryption	8192	4,038.8 ns	79.7916 ns	114.4348 ns	1.00
AES-GCM-SIV	Decryption	8192	3,609.7 ns	66.9556 ns	62.6303 ns	0.89

Performance (macOS)

BenchmarkDotNet=v0.11.1, OS=macOS Mojave 10.14 (18A391) [Darwin 18.0.0]
Intel Core i7-5557U CPU 3.10GHz (Broadwell), 1 CPU, 4 logical and 2 physical cores
.NET Core SDK=3.0.100-alpha1-009640
  [Host] : .NET Core 3.0.0-preview1-27004-04 (CoreCLR 4.6.27003.04, CoreFX 4.6.27003.02), 64bit RyuJIT

Method	Categories	Size	Mean	Error	StdDev	Scaled
AES-GCM	Encryption	128	503.1 ns	0.2081 ns	0.1737 ns	1.00
AES-GCM-SIV	Encryption	128	315.4 ns	0.1813 ns	0.1514 ns	0.63
AES-GCM	Decryption	128	517.2 ns	0.4337 ns	0.3621 ns	1.00
AES-GCM-SIV	Decryption	128	368.2 ns	0.1659 ns	0.1385 ns	0.71
AES-GCM	Encryption	1024	795.1 ns	1.0668 ns	0.9979 ns	1.00
AES-GCM-SIV	Encryption	1024	666.7 ns	0.5449 ns	0.4830 ns	0.84
AES-GCM	Decryption	1024	779.5 ns	1.2164 ns	0.9497 ns	1.00
AES-GCM-SIV	Decryption	1024	697.7 ns	0.8535 ns	0.7566 ns	0.90
AES-GCM	Encryption	4096	1,711.2 ns	2.1837 ns	2.0426 ns	1.00
AES-GCM-SIV	Encryption	4096	1,767.6 ns	2.5230 ns	2.2366 ns	1.03
AES-GCM	Decryption	4096	1,711.9 ns	6.3718 ns	5.9602 ns	1.00
AES-GCM-SIV	Decryption	4096	1,780.6 ns	1.7417 ns	1.5440 ns	1.04
AES-GCM	Encryption	8192	2,981.2 ns	8.2092 ns	7.6789 ns	1.00
AES-GCM-SIV	Encryption	8192	3,276.0 ns	4.5095 ns	3.7657 ns	1.10
AES-GCM	Decryption	8192	2,991.5 ns	6.8195 ns	6.3789 ns	1.00
AES-GCM-SIV	Decryption	8192	3,205.7 ns	4.4109 ns	4.1260 ns	1.07