GNUPG 

GNUPG

I've heard about PGP (Pretty Good Privacy) for a while. I never really bothered since I don't have a need nor paranoia to encrypt my files. Today however, is an exception, my colleague wanted me to find him an encryption software and since I'm an open source fan I opted against using winzip's encryption feature and searched an opensource alternative instead.

Googling for "encryption software" I stumbled upon GNUPG (GNU Privacy Guard). It's available on a number of platforms including Linux, Mac and Windows.

Downloaded the binary, followed instructions in a related online tutorial and voila! I got it working under 10 mins. I'm sure others will get it under 5 mins.

PGP works using a private/public key pair (aka asymmetric encryption). In a nutshell, one would use a public key to encrypt a message or file and use the private key from that pair to decrypt it. A practical example would be, say you want to send me a confidential message. You'd encrypt the message using my public key which as the name implies is publicly available (either I publish this on the web or sent or made it beforehand) and sent via email or any electronic means.

Upon receiving the message, I as the recipient will use my private key to decrypt it. The algorithm employed is quite clever in that the key pair works such that one can only use the private key to decrypt a message encrypted with a public key and not when using one key alone (i.e. you cannot use the public key to decrypt a message encrypted using that same public key, same goes for the private key). If you were able to, that would be called secret-key or symmetric key encryption which is quite different ;-)

I tried to paste my public key here but the blog engine isn't displaying properly :-(

GNUPG for Windows instructions can be found in:
http://www.glump.net/content/gpg_intro/html_onepage/gpg_intro.html

GNUPG can be downloaded from:

http://www.gnupg.org/(en)/download/