Cryptography Challenge for Y5

Scratch Cryptography File

https://scratch.mit.edu/projects/11939624/

The Black Chamber Caesar cipher tool

http://www.simonsingh.net/The_Black_Chamber/caesar.html

Can you decipher the following text?

PWXVW-FJPAXIN RDBEJIXCV TSJRPIXDC TFJXEH EJEXAH ID JHT RDBEJIPIXDCPA IWXCZXCVPCS RGTPIXKXIN ID JCSTGHIPCS PCS RWPCVT IWT LDGAS.