Encryption using Symmetric keys

Scenario:

Encryption using Symmetric keys

Solution:

          Symmetric encryption is fast and for large amounts of data and requires a shared key.

 
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public sealed class AESEncryption
        {
           public (string key, string IVBase64) SymmetricEncryptionKeyIV()
            {
                //256 byte
                var key = GetRandomText(32);

                var cipher = CreateCipher(key);

                var IVBase64 = Convert.ToBase64String(cipher.IV);

                return (key, IVBase64);
            }

            private Aes CreateCipher(string keyBase64)
            {
                var cipher = Aes.Create();
                cipher.Mode = CipherMode.CBC;

                cipher.Padding = PaddingMode.ISO10126;

                cipher.Key = Convert.FromBase64String(keyBase64);

                return cipher;
            }

            private string GetRandomText(int length)
            {
                var base64String = Convert.ToBase64String(GenerateRandomByte(length));

                return base64String;
            }

            private byte[] GenerateRandomByte(int length)
            {
                var byteArray = new byte[length];
                RandomNumberGenerator.Fill(byteArray);

                return byteArray;
            }

            public string Encrypt (string text, string IV, string key)
            {
                var cipher = CreateCipher(key);
                cipher.IV = Convert.FromBase64String(IV);

                var crytoTransform = cipher.CreateEncryptor();

                var plaintext = Encoding.UTF8.GetBytes(text);

                var cyphText = crytoTransform.TransformFinalBlock(plaintext, 0, plaintext.Length);

                return Convert.ToBase64String(cyphText);
            }

            public string Decrypt(string encryptedText, string IV, string key)
            {
                var cipher = CreateCipher(key);
                cipher.IV = Convert.FromBase64String(IV);

                var crytoTransform = cipher.CreateDecryptor();

                var enc = Convert.FromBase64String(encryptedText);

                var plainBytes = crytoTransform.TransformFinalBlock(enc, 0, enc.Length);

                return Encoding.UTF8.GetString(plainBytes);
            }
        }

          Using 128 byte salt and 256 byte key and iterations of 10000, create a hashed password. If the                  iterations has been updated then use the new one to rehash the password.

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        static void Main(string[] args)
        {
            var data = "User Data";
            var s = new AESEncryption();

            var (Key, IVBase64) = s.SymmetricEncryptionKeyIV();

            var encryptedData = s.Encrypt(data, IVBase64, Key);
            Console.WriteLine(encryptedData);

            var decryptedData = s.Decrypt(encryptedData, IVBase64, Key);
            Console.WriteLine(decryptedData);

            Console.ReadLine();
        }