This information is cited from the following website: http://www.xinotes.org/notes/note/1302/
1. Download the xml security source distribution (curently version 1.4.4). [1]
2. Build with ant.
3. Create your own library jar (only the apache classes, no javax):

    jar -cf xmlsec-1.4.4.jar -C build/classes org

4.  Copy xmlsec-1.4.4.jar to the libs directory of your Android project.


[1] http://archive.apache.org/dist/santuario/java-library/