Recently XML has become an active research area. In particular, the need for an efficient secure access control of dynamic XML data in a ubiquitous data stream environment has become very important. But Role-based Prime Number Labeling (RPNL) has some problems. For example, The RPNL does not know a relationship between nodes such as ancestor-descendant relationship. The RPNL does not take update operation of an XML document into consideration. We propose a new labeling scheme for efficient secure access control method in dynamic XML data stream. The e-RPNL supports the process of dynamic XML data without re-labeling existing labels. We have shown that our approach is efficient and secure through experiments.