Krypt.Core 1.0.0

Krypt

Krypt is a .NET library for encryption and decryption of data. It provides a simple and secure way to protect sensitive information in your applications.

Features

• AES-256-CBC encryption with automatic IV generation
• Key derivation from any passphrase via SHA-256
• Multiple overloads: string, byte[], and Stream (sync + async)
• IV prepended to cipher output — no extra plumbing needed
• Zero dependencies beyond the .NET BCL

Installation

dotnet add package Krypt.Core

Quick Start

Encrypt & decrypt a string

using Krypt;

string secretKey = "secretkey123";
string toEncrypt = "Hello World!";

string encrypted = Krypt.Encryption.KryptAes.Encrypt(toEncrypt, secretKey);
Console.WriteLine($"Encrypted: {encrypted}");

string decrypted = Krypt.Encryption.KryptAes.Decrypt(encrypted, secretKey);
Console.WriteLine($"Decrypted: {decrypted}");
// Output:
// Encrypted: <base64 cipher>
// Decrypted: Hello World!

Encrypt & decrypt raw bytes

using Krypt.Encryption;

byte[] data   = File.ReadAllBytes("document.pdf");
byte[] cipher = KryptAes.Encrypt(data, "my-secret-passphrase");
byte[] plain  = KryptAes.Decrypt(cipher, "my-secret-passphrase");

Encrypt & decrypt a file (stream)

using Krypt.Encryption;

using FileStream input  = File.OpenRead("video.mp4");
using FileStream output = File.Create("video.mp4.enc");

KryptAes.Encrypt(input, output, "my-secret-passphrase");

using FileStream cipher   = File.OpenRead("video.mp4.enc");
using FileStream restored = File.Create("video_restored.mp4");

KryptAes.Decrypt(cipher, restored, "my-secret-passphrase");

Async stream (recommended for large files / web apps)

await KryptAes.EncryptAsync(inputStream, outputStream, "my-secret-passphrase", cancellationToken);
await KryptAes.DecryptAsync(cipherStream, outputStream, "my-secret-passphrase", cancellationToken);

API Reference

Technical Details

The IV is randomly generated on every Encrypt call and prepended to the output. Decrypt strips it automatically — you never need to manage the IV yourself.

Note: Key derivation uses a single SHA-256 pass for performance and portability. If you need stronger key stretching for user-facing passwords, consider pre-deriving your key with PBKDF2 or Argon2 before passing it to Krypt.

Requirements

• .NET 8 or later

License

MIT