Signatures: The secret behind modern end-to-end encryption
Now that most of our communications are digital, a problem arises: How to keep our messages private despite all the intermediaries? Internet Service Providers (ISPs) and Service providers (Facebook, Telegram, Line, WeChat…) are all in a position of Man-In-The-Middle (MITM) and are able to inspect, record, and even modify our communications without our consent or knowledge.
And this is before talking about malicious actors.
ISP - service provide (ex: Chat) - ISP - Bob -- You may think that you have nothing to hide, so it doesn’t matter.