Implementation of an encrypted string user type

AesCryptoProvider.cs

class AesCryptoProvider : ICryptoProvider
{
    private string password;

    public AesCryptoProvider(string password)
    {
        this.password = password;
    }

    public byte[] Encrypt(string inputText)
    {
        using (var rij = new AesManaged())
        using (var pdb = new Rfc2898DeriveBytes(password, 16))
        using (var encryptor = rij.CreateEncryptor(pdb.GetBytes(32), pdb.GetBytes(16)))
        {
            var textBytes = Encoding.UTF8.GetBytes(inputText);
            var encryptedBytes = encryptor.TransformFinalBlock(textBytes, 0, textBytes.Length);
            return pdb.Salt.Concat(encryptedBytes).ToArray();
        }
    }

    public string Decrypt(byte[] encryptedBytes)
    {
        var salt = encryptedBytes.Take(16).ToArray();
        using (var rij = new AesManaged())
        using (var pdb = new Rfc2898DeriveBytes(password, salt))
        using (var decryptor = rij.CreateDecryptor(pdb.GetBytes(32), pdb.GetBytes(16)))
        {
            try
            {
                var decryptedBytes = decryptor.TransformFinalBlock(encryptedBytes, 16, encryptedBytes.Length - 16);
                return Encoding.UTF8.GetString(decryptedBytes);
            }
            catch (CryptographicException)
            {
                return "[Wrong password]";
            }
        }
    }        
}

EncryptedStringUserType.cs

class EncryptedStringUserType : IUserType
{
    private readonly ICryptoProvider cryptoProvider;

    public EncryptedStringUserType(ICryptoProvider cryptoProvider)
    {
        this.cryptoProvider = cryptoProvider;
    }
    
    public object NullSafeGet(IDataReader rs, string[] names, object owner)
    {
        var data = NHibernateUtil.Binary.NullSafeGet(rs, names[0]) as byte[];
        return cryptoProvider.Decrypt(data);
    }

    public void NullSafeSet(IDbCommand cmd, object value, int index)
    {
        var data = cryptoProvider.Encrypt((string)value ?? "");
        NHibernateUtil.String.NullSafeSet(cmd, data, index);
    }

    public object DeepCopy(object value)
    {
        return value;
    }

    public object Replace(object original, object target, object owner)
    {
        return original;
    }

    public object Assemble(object cached, object owner)
    {
        return cached;
    }

    public object Disassemble(object value)
    {
        return value;
    }

    public SqlType[] SqlTypes
    {
        get { return new[] { new SqlType(DbType.Binary) }; }
    }

    public Type ReturnedType
    {
        get { return typeof(string); }
    }

    public bool IsMutable
    {
        get { return false; }
    }

    public new bool Equals(object x, object y)
    {
        return object.Equals(x, y);
    }

    public int GetHashCode(object x)
    {
        return x.GetHashCode();
    }
}