🧬 CocoTail – Hybrid Argon2id + Keccak KDF Framework

Powerful. Secure. Memory-Hard. A next-generation Key Derivation Framework combining Keccak-f[1600], SHA-512, and Argon2id for high-security password hashing and key derivation.

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🚀 Overview

CocoTail is a hybrid key derivation framework that merges:

• The Keccak-f[1600] sponge (basis of SHA-3) for initial diffusion and entropy spreading.
• The well-tested SHA-512 for robust intermediate hashing.
• Argon2id (RFC 9106) for memory-hard finalization, resistant to GPU/ASIC attacks.

This dual-primitive design provides extremely high resistance against:

• Dictionary and brute-force attacks.
• Specialized hardware attacks.
• Side-channel attacks and memory leakage.

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✨ Key Features

Category	Description
🔐 Security	Hybrid Keccak + SHA-512 + Argon2id for layered defense.
🧠 Memory-Hard	Forces sequential memory access to slow down parallel attacks.
⚙️ Configurable	Control memory, iterations, and output size.
🧩 Compatible	Stable API: ComputeHash(byte[] input, byte[] salt)
🧼 Secure Memory	Sensitive buffers zeroed automatically.
🧱 Production-Ready	Fallback PBKDF2-HMAC-SHA512 for FIPS environments.

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🧪 Usage Example

using CocoTail;
using System.Security.Cryptography;
using System.Text;

var coco = new CocoTailDigest(outputLengthBits: 512, memoryBlocks: 1024, timeCost: 2);

string password = "my_ultra_secret_password_456!";
byte[] passwordBytes = Encoding.UTF8.GetBytes(password);
byte[] salt = RandomNumberGenerator.GetBytes(16);

byte[] hash = coco.ComputeHash(passwordBytes, salt);

Console.WriteLine($"Salt: {BitConverter.ToString(salt).Replace("-", "")}");
Console.WriteLine($"Hash: {BitConverter.ToString(hash).Replace("-", "")}");

Sample Output:

Salt: BEA005D5321F146781B322C4358635EC
Hash: 42CE3AF7FE0B39BB2AD1FF2C5D6EC84465C3506957F4668F0272FFA9C93210B1944D4CADB1FAE3A998961C4F7E10C3BB986EFD1026BF85AB12216C522D94C1AC

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⚙️ Recommended Parameters

Scenario	Memory (MB)	Iterations	Output (bits)
Desktop / Local App	64	3	512
Server Backend	128	4	512
Embedded Devices	16	2	256

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🧩 Internal Architecture

 Input (password + salt)
          │
          ▼
 ┌────────────────────────┐
 │  Keccak-f[1600] Sponge │  → Diffusion & entropy
 └────────────────────────┘
          │
          ▼
 ┌────────────────────────┐
 │      SHA-512 Mix       │  → 64-byte intermediate hash
 └────────────────────────┘
          │
          ▼
 ┌────────────────────────┐
 │     Argon2id Layer     │  → Memory-hard finalization
 └────────────────────────┘
          │
          ▼
     Final Output (Hash)

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🛡️ Security

• ✅ Argon2id compliant with RFC 9106
• ✅ Keccak-f[1600] validated on SHA-3 test vectors
• ✅ All critical buffers use ArrayPool and are zeroed after use
• ✅ No unsafe code, fully managed .NET implementation

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📦 Installation

Include the source directly in your .NET solution:

git clone https://github.com/ZygoteCode/CocoTail.git

Or add as a project reference. Future NuGet support planned:

dotnet add package CocoTail

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🧰 API

public sealed class CocoTailDigest : IDisposable
{
    CocoTailDigest(int outputLengthBits = 512, int memoryBlocks = 8192, int timeCost = 3);
    byte[] ComputeHash(byte[] input, byte[] salt);
}

Parameters:

• outputLengthBits – output hash length in bits (multiple of 8)
• memoryBlocks – number of memory blocks used internally
• timeCost – number of mixing passes

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🧾 License

MIT License © 2025 Created with ❤️ by [ZygoteCode]

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🧠 References

• RFC 9106 – Argon2id Password Hash
• Keccak Reference
• NIST FIPS 202 – SHA-3 Standard

⚡ CocoTail Hybrid-Argon2id – A research-grade KDF made production-ready and extremely powerful.