Though it is entirely possible that there is some other meaning, I feel that the religious imagery is to obvious to avoid. The crosses are reminiscent of the Orthodox crosses, the top bar originally had the words "Jesus of Nazareth, King of the Jews". the bottom crooked bar was his foot rest, which legend has it, with his last strength Jesus kicked the bar such that one side pointed to the heavens and one to hell. The fact that the cross is up side down, could be pointing towards saint peter, who many believe requested to be crucified upside down, as he did not believe he was worthy of dieing in the same fashion as Jesus. I believe that the cipher used here is related to the Romans, or atleast from that era.