Answer:
What does “encryption” mean?
What is “public key cryptography”?
What kind of encryption was available a long time ago?
What are “key distribution problems”?
What are “cryptanalysts”?
Explanation:
The very purpose of the informational text, such as this, is to, well, obviously, inform us on certain topic. But, in order to be informed, we first must understand the text and be familiar with the used words.
Basically, the text is about private information protection, and that's, more or less, clear to everyone. However, the terms used to explain it are probably not as much.
So, first thing to do to fully understand this text is to ask what all of these words and expert terms mean. In other words, knowing what a RSA cipher is can be helpful, but knowing where to buy one is completely irrelevant to comprehending this excerpt, making the fifth option incorrect.
