How can I implement encryption in C#?

How can I implement encryption in C#?

You can use the System.Security.Cryptography namespace in C#. What type of encryption are you looking for, symmetric or asymmetric?

I'm interested in symmetric encryption. Can you provide an example?

Sure! Here's a simple example using AES for symmetric encryption:

using System;
using System.IO;
using System.Security.Cryptography;
using System.Text;

public class AesEncryption
{
    public static string Encrypt(string plainText, string key)
    {
        using (Aes aes = Aes.Create())
        {
            aes.Key = Encoding.UTF8.GetBytes(key);
            aes.GenerateIV();
            using (var encryptor = aes.CreateEncryptor(aes.Key, aes.IV))
            {
                using (var ms = new MemoryStream())
                {
                    ms.Write(aes.IV, 0, aes.IV.Length);
                    using (var cs = new CryptoStream(ms, encryptor, CryptoStreamMode.Write))
                    {
                        using (var sw = new StreamWriter(cs))
                        {
                            sw.Write(plainText);
                        }
                    }
                    return Convert.ToBase64String(ms.ToArray());
                }
            }
        }
    }
}

Make sure to use a secure key!

What about decryption? How can I decrypt the data?

You can decrypt the data using a similar method. Here's an example of a decryption method:

public static string Decrypt(string cipherText, string key)
{
    byte[] fullCipher = Convert.FromBase64String(cipherText);
    byte[] iv = new byte[16];
    Array.Copy(fullCipher, 0, iv, 0, iv.Length);
    byte[] cipher = new byte[fullCipher.Length - iv.Length];
    Array.Copy(fullCipher, iv.Length, cipher, 0, cipher.Length);

    using (Aes aes = Aes.Create())
    {
        aes.Key = Encoding.UTF8.GetBytes(key);
        aes.IV = iv;
        using (var decryptor = aes.CreateDecryptor(aes.Key, aes.IV))
        {
            using (var ms = new MemoryStream(cipher))
            {
                using (var cs = new CryptoStream(ms, decryptor, CryptoStreamMode.Read))
                {
                    using (var sr = new StreamReader(cs))
                    {
                        return sr.ReadToEnd();
                    }
                }
            }
        }
    }
}

This will allow you to retrieve the original plaintext.