// Then
        assertNotNull(hash);
        assertEquals(16, hash.length); // MD4 produces 128-bit hash
    }

    @Test
    @DisplayName("Should calculate MD5 hash correctly")
    void testMD5Hash() {
        // Given
        String input = "Hello World";
        byte[] data = input.getBytes();

        // When
        MessageDigest md5 = Crypto.getMD5();
        byte[] hash = md5.digest(data);