Simple PBKDF2 based AES-256 encryption

SimpleAES.cs

    public class SimpleAES
    {
        private const int SALT_SIZE = 8;
        private const int KEY_SIZE = 256;

        public static string Encrypt(string text, string passphrase)
        {
            byte[] result = null;
            if (Encrypt(Encoding.UTF8.GetBytes(text), passphrase, ref result))
            {
                return Convert.ToBase64String(result);
            }
            return null;
        }

        public static string Decrypt(string encr, string passphrase)
        {
            byte[] result = null;
            if (Decrypt(Convert.FromBase64String(encr), passphrase, ref result))
            {
                return Encoding.UTF8.GetString(result);
            }
            return null;
        }

        public static bool Encrypt(byte[] buffer, string passphrase, ref byte[] result)
        {
            try
            {
                var salt = GetRandomBytes(SALT_SIZE);
                using (var cipher = GetCipher(passphrase, salt, KEY_SIZE))
                using (var ms = new MemoryStream())
                using (var trans = cipher.CreateEncryptor(cipher.Key, cipher.IV))
                using (var cs = new CryptoStream(ms, trans, CryptoStreamMode.Write))
                {
                    ms.Write(salt, 0, salt.Length);
                    cs.Write(buffer, 0, buffer.Length);
                    cs.FlushFinalBlock();
                    result = ms.ToArray();
                    return true;
                }
            }
            catch (Exception ex)
            {
                Trace.TraceError(ex.ToString());
            }
            return false;
        }

        public static bool Decrypt(byte[] buffer, string passphrase, ref byte[] result)
        {
            try
            {
                var salt = new byte[SALT_SIZE];
                Array.Copy(buffer, salt, SALT_SIZE);
                using (var cipher = GetCipher(passphrase, salt, KEY_SIZE))
                using (var ms = new MemoryStream())
                using (var trans = cipher.CreateDecryptor(cipher.Key, cipher.IV))
                using (var cs = new CryptoStream(ms, trans, CryptoStreamMode.Write))
                {
                    cs.Write(buffer, SALT_SIZE, buffer.Length - SALT_SIZE);
                    cs.FlushFinalBlock();
                    result = ms.ToArray();
                    return true;
                }
            }
            catch (Exception ex)
            {
                Trace.TraceError(ex.ToString());
            }
            return false;
        }

        private static byte[] GetRandomBytes(int size)
        {
            var salt = new byte[size];
            var rng = new Random();
            rng.NextBytes(salt);
            return salt;
        }

        private static Aes GetCipher(string passphrase, byte[] salt, int keysize)
        {
            var aes = Aes.Create();
            aes.KeySize = keysize;
            aes.Padding = PaddingMode.PKCS7;
            aes.Mode = CipherMode.CBC;
            using (var pbkdf2 = new Rfc2898DeriveBytes(passphrase, salt, 100000))
            {
                aes.Key = pbkdf2.GetBytes(32);
                aes.IV = pbkdf2.GetBytes(16);
            }
            return aes;
        }
    }