As previously reported, interference hampered the efforts of code-breakers at Bletchley Park to intercept the message on Thursday. They deliberately used wartime radio equipment to intercept the messages in an effort to make the exercises as authentic as possible. Bletchley Park was unable to get a good copy of the signal until 4.30pm on Thursday, about two hours after an amateur cryptographer in Germany had intercepted and decoded the most heavily encrypted of three messages that featured in the challenge.