Question

You are a Spartan general preparing for battle against the Persians on the outskirts of Thermopylae. You know the Persian forces greatly outnumber your own and are fully prepared to make a last stand holding off the Persian army. With a last minute stroke of luck, you receive word that a Persian messenger was captured and you’ve come upon a copy of the Persian attack plans! Unfortunately, the Persians’ plans appear to be written in a strange language that you haven’t seen before. You call upon Greece’s smartest mathematician & linguist to help you understand. Her face becomes increasingly solemn as she unravels the captured scroll: "I’m afraid this isn’t a new language… It’s the impenetrable ROT13 encryption algorithm. I’ve heard of it in legends, but never seen it before. We will never be able to crack it in time…"

With the lives of your soldiers on the line, you’re determined the crack the algorithm and use the stolen attack plans to win the battle.
1) What is the ROT13 algorithm? How does the algorithm work?
2) What does the encrypted message say?
3) If you were the Spartan general, how would this message change your plans?

Answer 1

ROT13 is a substitution cipher that shifts letters by 13 positions. Decryption is as simple as reapplying the algorithm. Knowing the Persian plans could change the Spartan's defense strategy in the Battle of Thermopylae.

Step-by-step explanation:

The ROT13 algorithm is a simple substitution cipher used in cryptography where each letter in the original text is replaced by a letter 13 positions down the alphabet. So, A would become N, B would become O, and so on, wrapping around to the beginning of the alphabet if necessary. Since the Latin alphabet has 26 letters, applying ROT13 to encrypted text will decrypt it, and vice versa.

To decrypt a ROT13 message, you simply reverse the process: N becomes A, O becomes B, etc. This means that the encrypted attack plans can be quickly decrypted by applying ROT13 again. Assuming the captured message was vital to the Persian strategy, the Spartan general could use the decrypted information to anticipate the Persian movements and prepare a more effective defense or counter-attack, potentially altering the outcome of the Battle of Thermopylae.