We are going to focus on “Public Key Encryption.” GNUPG creates a key pair – (1) a public key (2) a private key. Alice and Bob both have a public key and a private key. They exchange their public key to enable encrypted data exchange. Alice uses Bob’s public key to send him encrypted data – Bob uses his private key to decrypt that data.
It is usual that having created your key pair – you upload your public key to a key server. This is to verify the key belongs to to the person. Meeting people and verifying their id – passport driving licence works phone number phone number of wife or girlfriend is the best way to ensure that a person is who he/she says they are. But keep in mind the police and the intelligence services give all their operatives completely false ids and form intimate relationships with fellow “activists.”
If you are law firm or business then you have work colleagues – your firm may have a “public key” for sharing communications – and senior members of staff may also have their own private keys. If your just an ordinary man or women then you can set up your own family network exchanging your public keys within that.
To be frank every “group” that you know about has spies. If you belong to a FaceBook group that is very active – then your going to have to accept the fact that one or two of your friends are working for police intelligence MI5 or MI6. They maybe very active or sleeping – but the fact is you have them in your group and your friends list. Even within the Labour Party or any political group spies are at work – Mossad run “Friends of Israel” an open public organisation but run by Israel’s intelligence agency and FaceBook is filled with Mossad agents.
This is also true if you work for a large corporation – foreign agents are always after your trade secretes – what deals you are making – in sensitive legal cases – you are always faced with the fact that the intelligence services want to know what you are doing. There is always some one who’s job it is is to spy on you. You have to accept as fact that without encrypting your communications you are handing over ALL YOUR PRIVATE AND PUBLIC DATA TO THE STATE’S AGENCIES.