Our readingWhat is a korrent?
Handling a change of keys is not a backdoor; it is how public-key cryptography works, and interception stays detectable by the sender.
Drawn from what Moxie Marlinspike said
What these subjects mean
privacy Keeping what people say to each other between them: end-to-end encryption, backdoors, and what a company will shut down rather than break.
cryptography Keeping a computation secret from the machine running it -- obfuscation, permutations, and what has been proved.