Essays / End of High School Essay: Quantum Cryptography [2]

Hello, I'm in my last High School year, and have to submit an essay at the end of the year which will count to my deploma's grade.

It's similar to the IB's extended essay in its functioning. As you can probably tell through the title, I've settled on Quantum

Cryptography. My essay requires 4000 words, and more importantly it needs to have a problematic. The essay will only be as strong
as it's weekest link, in this case the problematic, which should be discussed in the introduction and conclusion. The reason I'm
writing on this forum is because I can't find a good problematic. I'd like to stay in the boundaries of computer science, and not

diverge into social studies or anything of that sort. I've contemplated the following topics: "Is quantum cryptography truely
unbreakable", or "Will quantum cryptography replace classical cryptography".
I was hoping someone will be able to point me to a good direction. Thanks in advance for any help!