The growth of the Internet has made cryptography is more important and critical issue in electronic application systems. Unless the system is able to provide some mechanisms to ensure security services, the system will have problems to be accepted. In this paper, the authors propose a cryptosystem (encrypting/decryption) for XML data using Vigenere cipher algorithm and EL Gamal cryptosystem. Such a system is designed to achieve some of security aspects such as confidentiality, authentication, integrity, and non-repudiation. They used XML data as an experimental work.