Anonymous A started this discussion 15 years ago#4,445
A PGP key(pair) allows people to encrypt something and know only you can open the file, and allows you to digitally sign files (messages) so people know they came from you.
You get two keys: a private key (which only you know) & a public key (which you give to everyone).
Anything encrypted with one can only be decrypted with the other.
If you can decrypt something with my public key, you know it came from me, because only I have my private key.
If you encrypt something with my public key you know that only I can read it, because only I have my private key.
Software generates a key pair, which is stored on your PGP programs "keyring", and then you give out your public key to as many people as you can. Then you can set up software to sign messages, and to encrypt them so only the person you are talking to can decrypt it.
Software to use to generate a keypair, and start with PGP.
Macintosh: Applications > Utilities > Keychain
GNOME: Applications > Accessories > Password Management (or run "seahorse" in ALT+F2