Probability Question: What is the Probability of patterns in Zodiac Killer Z340 cipher?
Good day all,
Wanted to get some outside opinion on a probability question that is a matter of debate in true crime and Zodiac Killer mystery.
I am having issues solving it as I am not sure how to tackle the probability of this problem*******
The Zodiac Killer sent a message in 1969 and cryptographers have noted some patterns that seem somewhat of a mystery. The Z340 was broken and transcribed a few years ago, but this pattern is debated as either being intentionally put there or just a random pattern that appears by chance.
The cipher is a homophonic substitution cipher with a transposition scheme. The scheme is a bit odd, but if you want to see how it was solved and transcribed please see the below video:
https://www.youtube.com/watch?v=-1oQLPRE21o&t=486s
See below for patterns in question, the highlighted symbols are highlighted in red:
Below is the transcribed 340 cipher:
What do you all think what is the probability of these patterns appearing in the cipher by chance?
References:
Cracking the 340 cipher:
https://www.youtube.com/watch?v=-1oQLPRE21o&t=486s
More mysteries about the cipher:
https://www.youtube.com/watch?v=ByMe8D9sxo4&t=653s