The appearance of the purported cipher text sheds a poor light on our security About a year and a half after Prime Minister Imran Khan was removed from office, The Intercept magazine of the USA ...

But the goal remains the same: to transfer a readable message (plain text) into something an unintended reader cannot understand (cipher text).

Bauer reveals how Caesar's cipher worked, substituting each plain-text letter with a letter a fixed number of places away in the alphabet.

The Purple Machine would use hundreds of thousands of cipher alphabets before it would repeat one, thus eliminating any obvious patterns in the cipher text.