Although currently still in the planning stages of implementation for our company website, we are considering different methods and technologies that successful at addressing scalability, performance, and security (as in people can't steal or easily reverse engineer our financial algorithms) concerns.
According to several posts here on stack overflow, it appears that since we have already completed a good deal of algorithms via Java for our desktop applications, accessing these algorithms via Java Servlets and JSON requests (as can be seen here and here) online might be a good choice, as it would save considerable time and money by not having to rewrite them in a different language.
Before moving forward however, I would like to know if the time and money saved by this approach would be worth it in the long run, and specifically, is accessing (java methods and array data) via JSON and Javascript both secure and scalable, compared to say rewriting all of them in straight javascript? Also, is support for applets and servlets ubiquitous, or is it possible that a good chunk of our user base would not be able to have access our website without having to download additional plugins?
In the ideal situation (minimizing learning new technologies), I would like to use technologies involving HTML5 canvass and JavaScript for all of the graphical stuff, but also be able to access small data via java algorithms (which will return an array with less than 100 indexes), however eventually on a large scale in terms of number of simultaneous users (no logins).
Is this a good option in terms of speed, compatibility, and security, or is there perhaps something that we overlooked?