Secret Cipher Coin

The cipher is one of the most well-known encryption techniques. Send secured messages to covert operators by using the inner disk as the real message and the outer disk as the encrypted message. For example, if you set #1 in the window, that means there's an alphabet code shift of 1. So, A=B, B=C, etc. The messaged recipient must also know the shift number to decode the message. Coin measures approximately 1.5 inches across. Using the Caesar shift (3 to the right), can you decipher GHQB HYHUBWKLQJ? Hint: Its every spy's favorite phrase...