There is no eivdence that I know of. If Apple suddenly signed every message with a third key (a Chinese gov key) how would people know? Maybe a jail broken phon

There is no eivdence that I know of. If Apple suddenly signed every message with a third key (a Chinese gov key) how would people know? Maybe a jail broken phone could detect this.. but only if the third key was added. They could do it to specific people and no one would know until it happened. I have no proof of this, only guessing what could happen.