I think security issues in internet of things and the cloud are important, but probably not catastrophic, because the technology adoption has been somewhat gradual and slow. Previous security or computer bugs show that we are capable of dealing with problems, when they come. You might remember, even the Year 2000 Problem, for example, was overcome. What is interesting is that the bigger the problem, the more investment it will attract so there are commercial opportunities in the future (see the link below). This also affects consumer products: people are already hacking Google Glass or using it to hack. You are in a great field of research, and in the beginning, it might be theoretical or in a computer laboratory but, if you can also start working with industry, companies, and government, that will be even better. I hope that you will be successful in your research,