Dedicated to
BubbleCat,
who introduced me to this awesome life-saving trick.
============
INTRO
PGP = Pretty Good Privacy
GPG = GNU Privacy Guard
For the layman, both terms mean the same thing, and is usually called PGP/GPG.
It was invented by the two good German fellas called Phil Zimmermann & Werner Kock.
We all owe them really deep if you ask me.
Their invention guarantees everybody's
true & real (not fake & perceived) liberty, privacy, and safety.
It is
open-source (assurance of existence of no
back-doors) and free.
Allowing us to send/receive encrypted messages/files over internet,
While
being sure that
only the intended person can decrypt it, and the
Man-in-the-middle only gets a bunch of garbage random scrambled text.==============================================
DIFFERENCE WITH
OTHER CRYPTOGRAPHY METHODS
When you send files/texts encryption using "password-based" methods to a friend, you must give them the password too, and if you tell them the password via email/phone/SMS/etc, the purpose of encryption is lost, since the Man-in-the-middle will hear the password too, and will be able to decrypt the file/text.
The only safe way to tell the password to your friend is to
go to your friend's place physically and
tell it to them face-to-face quietly in his/her ear.
PGP/GPG solves this problem by replacing the password with
2 keys.
Every person owns 2 keys:
- Public key:
You send this (via email/PM/etc) to anyone who wants to send you encrypted files/texts.
The Man-in-the-middle can hear it, but it will be totally useless to him/her, except humming it in toilet or using it to send you an encrypted "***K YOU". - Private key:
you keep this for yourself and NOT give it to anyone.
==============================================
THE PROCEDURE
Steps in order:
- you generate a pair of keys, a PUBLIC and a PRIVATE key (your friend do this too)
- you send the PUBLIC key to your friend, and receive his/her PUBLIC key (via email/chat/PM/SMS/etc)
- your friend uses your PUBLIC key to encrypt the file/text.
- your friend sends you the encrypted file/text (via email/PM/SMS/chat/etc)
- you decrypt the received encrypted file/text using your PRIVATE key.
- now you use your friend's PUBLIC key to encrypt the reply, and send it to him/her (via email/PM/SMS/chat/etc)
- your friend decrypts your encrypted reply using his/her own PRIVATE KEY.
Optional step:
- you can "sign" the file/text, so the receiver get sure that the file/text is indeed written and sent by you, not the Man-in-the-middle.
Very simple, amiright?
==============================================
SOFTWARES USING PGP/GPG
It is originally a shell/command-line program, which might appear "too hard and complicated" for the average layman.
Do not worry, there are lots of graphical clients (programs), open-source and free, which implement PGP/GPG.
One of the awesome of graphical clients is called "Portable PGP"It is written in
Java, and thus
runs on almost all platforms.
But you need to install
Java Runtime Environment for it to work.
==============================================
That's all folks!
This thread should be stickied if you ask me.
The more people learning how to use PGP/GPG, the better.
Post any questions you have,
I will gladly answer.