Re: [LUG] Symmetric encryption - gpg

[Roland Tarver <roland.tarver@xxxxxxxxxxxxxx>]

On 23/11/12 12:23, Neil Winchurst wrote:
> This may interest some of the list members.
>
> Nasty things can happen to a computer, eg fire, flood, theft, hard 
> disk failure. I do backup my home folder files, don't we all? But 
> there are just one or two files that I would be very upset to lose. 
> However they are private and personal, mostly financial, and I don't 
> want anyone else to be able to read them.
>
> To this end I use one of the less well known facilities in gnupg: 
> symmetric encryption. This enables me to encrypt a file without 
> worrying about keys and all that stuff. I use a terminal screen for 
> this. Open it up and cd to the relevant folder.
>
> Let's use secret.txt as a sample file. It is as simple as this:-
>
> gpg -c secret.txt
>
> You will be asked for a password, twice. This is to check that they 
> match. The -c option means symmetric encryption. A new file will 
> appear, secret.txt.gpg. The original file will still be there.
>
> This new file will be a binary encrypted file. If you want to have a 
> text encrypted file use the --armor option
>
> gpg --armor -c secret.txt
>
> The new file will be secret.txt.asc
>
> Decryption is also simple.
>
> gpg secret.txt.gpg or gpg secret.txt.asc
>
> No I did not forget an option, it will be recognised as an encrypted 
> file and set up for decryption. You will be asked for the password. If 
> the original file is still there you will be asked if you want to 
> overwrite it. If you want to decrypt to a new file name then go
>
> gpg -o result.txt secret.txt.gpg
>
> Note the order, output file first and then the file to decrypt. Now 
> the decrypted file will be called result.txt.
>
> I have been using Linux for many years now, but did not know about 
> symmetric encryption until last year.
>
> If everyone on the list knows all of this then I apologise for wasting 
> their time.
>
> Regards
>
> Neil
Hi Neil et al

Co-incidentally, I came across the following site with simple 
instructions on a similar/same topic.

http://www.thegeekstuff.com/2012/10/gnupg-basics/

Part of a series on cryptography apparently, which I will probably have 
a look through. But not right now.... Dashing off to work..! lol

Cheers roly :-)

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