I think you failed to think that through. Random alphanumeric input of that length would be 25log(36)=525=125 bits. It is 11 bits per word because it is chosen

I think you failed to think that through. Random alphanumeric input of that length would be 25log(36)=525=125 bits. It is 11 bits per word because it is chosen from a ~2000 words dictionary. Edit: should have reloaded, said by enough people already :D