Answer: Secret Code #94

The secret message says:

OAR

The shift was 9.

The secret note decoded: OAR
The note, decoded.

Letter by letter

Secret letterAJX
Real letterRAO

Decode it with Python

This program does the decoding for you. Change the secret and the shift to crack other messages!

secret = "XJA"
shift = 9
message = ""

for letter in secret:
    if letter.isalpha():
        number = (ord(letter) - ord("A") - shift) % 26
        message = message + chr(number + ord("A"))
    else:
        message = message + letter

print(message)

When you run it, it prints:

OAR

Did you know? Shift codes are very old. A Roman writer called Suetonius said that Julius Caesar wrote secret letters by shifting the alphabet by three. That’s why it’s often called the Caesar cipher.