[manquer]

frequency analysis works easily if you know the source language, i.e. English in this case, while entropy of the message is critical to cracking, complex approaches are not the only ones which are immune to attacks, for example simple ciphers like using a one time pad is mathematically impossible to crack.

[rocqua]

The power of a one time pad relies on the inherent entropy of the pad though. So attacks against a real one time pad still need to deal with entropy.