Many intelligence agencies or tech companies try to fool people by telling them that their backdoors are only for good people. I think there’s no need to say that’s a lie.

There’s no meaning in encryption or security when there’s a backdoor. There is no such thing as a backdoor that only lets the good guys in. If there’s a “master key” that unlocks millions of accounts, every cracker on the planet will be after it.

A compromised encryption backdoor could give cyber criminals access to your bank account, your personal messages and other sensitive information.

Don’t think crackers can steal the master key? Think again. Both the CIA and the NSA were breached in 2017 by mysterious organizations that stole and published the spy agencies’ cracking tools. The same year, cyber criminals stole an NSA exploit and used it in a massive, worldwide ransomware attack. The fact is, if the government or anyone else controls a master key, eventually it will get out.

Crackers aren’t the only threat: Governments may also use encryption backdoors for harm. The U.S. government has already revealed its willingness to spy on citizens without a warrant. If liberal democracies cannot be trusted, what about China, Russia, Saudi Arabia, or countless other authoritarian states? Encryption backdoors could be used by repressive regimes to help them persecute journalists, dissidents, religious minorities, the LGBT community, and anyone else they please.