Legend relates that a soldier, on his way to take part in one of the many wars of the Roman Empire, asked the good prophetess, Sibylla Cumana, about his fate
ibis redibis non morieris in bello
The challenge is to know where to put the period.
The interpretation of the prophecy depends on where lies the period;
Is it ibis redibis. non morieris in bello or is the proper answer ibis redibis non. morieris in bello?
The first version translates as "You will go, you will return. You will not be killed in battle".
The second, "You will go, you will not return. You will be killed in battle".
Our soldier, therefore, has a problem.
Without the key – the knowledge of where to put the period – he knows not whether he will live or die in battle.
The modern day battle
Rather than physically waving swords and trying to kill the enemy, the modern day battle is fought electronically.
Words must be disguised so that the enemy (who may be an apparent friend) cannot decipher them and divine their meaning to our disadvantage.
We need to keep our communications secret from prying eyes and ears.