Table of Contents

Threefish1024 Class

Definition

Namespace
Bodu.Security.Cryptography
Assembly
Bodu.Security.Cryptography.dll
Package
Bodu.Security.Cryptography 1.2.0
Source
Threefish.1024.cs

Provides a managed implementation of the Threefish-1024 tweakable symmetric block cipher, which operates on 1024-bit (128-byte) blocks using a 1024-bit key and a 128-bit tweak. This class cannot be inherited.

public sealed class Threefish1024 : Threefish, IDisposable
Inheritance
Threefish1024
Implements
Inherited Members
Extension Methods

Examples

using System.Security.Cryptography;
using Bodu.Security.Cryptography;
using Bodu.Security.Cryptography.Extensions;

using var tf = Threefish1024.Create();
tf.Key = RandomNumberGenerator.GetBytes(128); // 1024-bit key
tf.IV = RandomNumberGenerator.GetBytes(128); // matches the 1024-bit block
tf.Tweak = RandomNumberGenerator.GetBytes(16); // 128-bit tweak
byte[] ciphertext = tf.Encrypt(plaintext);
byte[] roundTrip = tf.Decrypt(ciphertext);

Remarks

Threefish is the tweakable block cipher underlying the Skein hash function. This variant supports a variety of cipher block modes (CBC, CFB, OFB, CTR) via the BlockMode property, and is suitable for scenarios such as disk encryption or format-preserving encryption where a tweak is useful.

For other block sizes, see Threefish256 and Threefish512.

Parameters at a glance.

  • Block size: 1024 bits (128 bytes).
  • Key size: 1024 bits (128 bytes).
  • Tweak size: 128 bits (16 bytes).
  • Default mode: CBC; default padding: PKCS7.

When to choose Threefish-1024. The widest Threefish variant - pick it when the surrounding construction (Skein-1024, custom long-tweak schemes, or extreme-margin disk-encryption layouts) requires the 1024-bit block. Throughput is lower than the 512-bit variant; the 256/512-bit variants are more practical defaults unless the wider block is a hard requirement.

Constructors

Threefish1024()

Initializes a new instance of the Threefish1024 class using a 1024-bit block size, 1024-bit key, and 128-bit tweak.

public Threefish1024()

Methods

Create()

Creates a new Threefish1024 instance with default parameters.

public static Threefish1024 Create()

Returns

Threefish1024

A new Threefish1024 instance.

Remarks

The key, initialization vector, and tweak are generated on demand the first time they are accessed unless assigned explicitly via Key, IV, or Tweak.

CreateCipher(byte[], byte[])

Instantiates the concrete Threefish block cipher with the specified key and tweak.

protected override ThreefishBlockCipher CreateCipher(byte[] key, byte[] tweak)

Parameters

key byte[]

The encryption key.

tweak byte[]

The tweak value.

Returns

ThreefishBlockCipher

A configured IBlockCipher instance for encryption or decryption.

Exceptions

ArgumentNullException

Thrown when key is null.

CryptographicException

Thrown when the underlying cryptographic algorithm fails.

Applies to

ProductVersions
.NET8, 10

See Also

Using Threefish-1024 (guide with full encrypt / decrypt examples)
Encryption basics
Cipher block modes
Padding
Threefish
Threefish256
Threefish512
Threefish1024Cipher
Skein1024