XML has been widely adopted for information exchange across various networks due to flexibility providing common syntax for messaging systems. XML documents may contain private information that cannot be shared by all user communities. Therefore, XML Security has a great importance to the overall security of the distributed systems. In this paper, we provide a comprehensive tutorial on XML security standards. The presented standards include XML signature and XML encryption. We describe how to create and verify XML signature and how to encrypt and decrypt XML data. This paper should serve as a roadmap for future research and basis for further exploration of relevant scientific literature and standard specifications.