It is widely believed that IPTV will be one of the major applications in future IP networks and that IP over optical networks will be a major component of the next generation Internet. However, it is not efficient to map a single multicast IPTV flow into one light tree because the required bandwidth of an IPTV flow is usually much less than the capacity of a light-tree. Furthermore, pay-per-view or secure flows should be sent only to authorized users. In this paper, we study the problem of multi-class multicast flow aggregation with the constraint that secure programs are sent to authorized nodes. We first describe the problem and prove it to be NP-complete. We then formulate an integer linear program (ILP) and give results for small scale problems. Heuristic algorithms are presented, and results show that our heuristics achieve good results in both small and large scale problems. Also simulations show that the ratio of secure programs over total programs has great impact on the final aggregation results.