though i have not cleared My SCEA Part 1 but below material are good reading for Security.
1) Sun Certified Enterprise Architect for Java™ EE Study Guide 2nd Edition, Chapter - 5
2) Sun Certified Enterprise Architect for
J2EE Study Guide (Allen) Chapter - 10
3) Sun Certified Enterprise Architect for J2EE™ Technology Study Guide (Mark Cade) Chapter - 5
4) Core Security
Patterns: Best Practices and Strategies for J2EE™, Web Services, and Identity Management Chapter 1-5
5)
http://java.boot.by/scea5-guide/ (Notes from Zaikin)
6)
http://scea.djcheng.com/ (Notes from Cheng)