What topic to choose for a bachelor's thesis (IB)?

Question

Information Security

I am a 4th year student in the direction of "Information security of automated systems". Coming up with a fictional system and imaginary vulnerabilities and threats is not very attractive, I already wrote a term paper on this topic.
I have been programming since school, I even came up with a couple of projects during my studies, I tried myself in C ++, php, node.js, C #, python (in cases when it is faster and easier on it). I like to understand everything, but I can’t think of an interesting task, from the topics proposed at the department, optimization and analysis of algorithms in matlab and the above-mentioned methods for protecting imaginary information (object).
From the ideas that are in my head right now:

1. Implementation of the authorization API with the generation of an electronic key, a certain system with several levels of protection for authorization in a variety of services (where my apishka will, of course, be screwed).
   
2. A web service that allows you to sign documents, generate digital signatures and perform similar functions.
   
3. Writing a library that implements a unique encryption algorithm or a set of algorithms.
   

The question of these topics is, firstly, their adequacy, and secondly, their relevance. I'm more of a pure web lover, but a simple program is not enough for a diploma.
I would like to hear some recommendations and suggestions.

Answer 1

"Methodology of protection of information from bachelors".

Answer 2

The topic of the diploma is determined by your supervisor of the diploma project. Shake it.