How Public and Private Encryption Key Works???

[seventrad]

[SOLVED] How Public and Private Encryption Key Works???

Hi guys,

I need to understand how PGP or GPG keys works!

1º) I need to send a email encrypted for a person. I have to send to her my public key and my secret password?

2º) I encrypts and signs my message with my private key and my password?

3º) My password is needed only to encrypted and sign? Or her is needed to decrypt too?

I read many tutorials about GPG and PGP but I don't understand how works the private and public encryption key.

 

[logicearth]

This is what you do. You want to send an encrypted message to someone. They send you their PUBLIC key. You encrypt the message with their PUBLIC key. When the person gets the message they decrypt it with there PRIVATE key. Alright? It works like this if you encrypt with the PUBLIC key only the PRIVATE key can decrypt it. If you encrypt with a PRIVATE key only the PUBLIC key and decrypt it. The latter form is (PRIVATE -> PUBLIC) is used for digital signatures.

Never send your password to anything anywhere to anyone. The only thing you should ever send is your PUBLIC key.


Step one, encrypt your message with your PRIVATE key, you will send your PUBLIC key to the person.
Step two, encrypt the message again using the person's PUBLIC key.
Step three, send the message.

More or less I've not used GPG/PGP much.

 

[seventrad]

Ok! Now the things are more clear for me.

Thank you!

 

[Mark24]

Step one, encrypt your message with your PRIVATE key, you will send your PUBLIC key to the person.
Step two, encrypt the message again using the person's PUBLIC key.
Step three, send the message.

More or less I've not used GPG/PGP much.

Why Step one?
You only use your private key for decryption and signing.
So if you are sending an encrypted mail you encrypt the mail with the recipient's public key (and usual also with your own public key, so you can decrypt you own mail).

The process here sounds complicated, but normally this is done within you mail client automatically. Just google for Enigmail http://enigmail.mozdev.org (Thunderbird) or gpg4o http://www.gpg4o.de (Outlook).
These plugins do all the magic automatically.


Mark

 

[logicearth]

Why Step one?

For signing. You sign your message with your private key before encrypting with the recipient's public key. You also replied to a very old thread...