Digital PSAT Reading and Writing Practice Question 242: Answer and Explanation

Question: 242

Though not the first to utilize encryption, Roman emperor Julius Caesar is perhaps the most notable early adopter. A man of many secrets, Caesar would send messages to his generals in which the letters of the alphabet had been shifted a set number of places (A became D, B became E, and so forth). The recipient of the message would be alerted to the cipher in advance and would thus decode the message upon delivery. The Caesar Shift was simplistic by today's standards, but in an era in which very few could read in the first place, the encryption was effective.

The text most strongly suggests that the encryption used by Julius Caesar was successful in large part due to

• A. its mathematical complexity.
• B. a lack of widespread literacy at the time.
• C. its ancient historical roots.
• D. its incapacity to be physically intercepted.

Correct Answer: B

Explanation:

B. The text states that “The Caesar Shift was simplistic by today's standards, but in an era in which very few could read in the first place, the encryption was effective.” So, because the ability to read (i.e., literacy) was not widespread, this encryption method was effective. There is no indication that the cipher was mathematically complex, making Choice A incorrect. While it had ancient historical roots from centuries before the present day, the author does not indicate that this had a direct influence on its effectiveness, making Choice C incorrect. Finally, Choice D is incorrect because the text implies that even with physical interception, the messages would still be safe because of the lack of literacy.