Encrypt files using my secret key

[David Shaw]

On Apr 7, 2008, at 8:57 AM, paulo.s.rod wrote:
> Guys,
>
> Please, is that possible to encrypt files with gnupg using my secret  
> key ? Then other people could decrypt it using my public key, in  
> order to have authenticity, that is, it came from me ?

Not exactly.  What you are looking for is a "signature".  Signatures  
are made using your secret key, and can be verified by your public  
key, and it does show that it came from you (or at least, that it came  
from your key).

However, signatures do not encrypt the data, so you get authenticity,  
but not confidentiality.  If you want to encrypt also, you must  
encrypt on top of the signature.  GPG can do this with "--sign -- 
encrypt".

David