There are many research articles from same author of above papers in OCDMA security domain.Dissertation if woek also present on internet.I found some more good papers of same author
http://col.org.cn/abstract.aspx?id=COL201109120602-05
http://www.sciencedirect.com/science/article/pii/S0030402610002470
http://www.sciencedirect.com/science/article/pii/S0030402610002494