The backdoor mandate was part of an anti organized criminality law, Bruno Retailleau (interior minister) pretend criminals use encrypted chat to communicate and so backdoor is required to intercept their communications. makes sense to the average non tech people. The sad truth however is that it wouldn't even solve the issue, criminals will always be able to use encrypted communications: there are open source softwar…
Wouldn't law enforcement just use Pegasus style zero-days to spy on the their targets? So why all the hubbub about making backdoors that become vulnerabilities for nefarious users too? Like why bother convicting Signal to create a backdoor for you, when you can put your nations geniuses to find some RCE bugs in Qualcomm or Apple modems or SoCs, and spy on them that way? This way nobody's the wiser.
Onetime pad: messages are encrypted using an key that has the same length as the message
An enigmalike machine: the enigma has some problems, but that can easily be fixed. If someone uses more complicated keys than AAA they should be safe from reading the messages.