Data encryption and Ubuntu, Part II

[Hamish Taylor]

In a continuing series of articles highlighting that GNU/Linux is a viable replacement operating system, today we're exploring how to encrypt local files using PGP in the popular Ubuntu distribution.

In the previous article of this series, I wrote about encrypting and securing files that you don't want anyone else to see by setting up a Private directory in your Home directory.

But sometimes you have to share files and you still don't want just anyone to be able to see them. For example, when I travel I have copies of my passport, travel insurance, drivers licence and other information. To protect myself against potential identity theft, I encrypt these files.

Maybe you are a medical researcher and have confidential patient information you need to protect, or a financial planner or mortgage broker wanting to protect client data, or a journalist or secret intelligence agent wanting to protect sources, or an engineer working on an upcoming technology that can't be exposed to the market just yet, or... There are lots of perfectly legitimate reasons why people want to encrypt and protect their data. Can you think of examples relevant to you?

I could put my travel files into that Private directory on my laptop and if I lost my laptop I'd be confident that no-one can access my files (unless they can guess my password). However, neither can I! So, I tend to share these files around as a backup.

When I encrypt the files, I am able to leave these files pretty much anywhere:
 - I can upload them to free storage sites on the Internet and know that I can retrieve them if I need to
 - I'm able to burn them to CD or copy them onto USB sticks and leave them on trains, in taxis or whatever and not have to worry
 - I can email them to a friend for safe keeping, knowing that if I need them, I can ask the friend to email them back
 - Or I can email them to myself on GMail, Yahoo! or Hotmail, knowing that I can access that from any Internet connection

Without the ability to decrypt these files, and as only I hold the key to do that, they are useless 1s and 0s to everyone else.

So, now we know why we encrypt files, how do we encrypt files?



Article Link at http://www.itwire.com/content/view/21939/1162/

[Lawrence D'Oliveiro]

Just worth noting that, while public keys are not confidential, people who are given a copy of your public key need some assurance that it really came from you, and not from somebody else. Otherwise confidential stuff they try to send to you could be readable by some unwanted third-party, and conversely confidential stuff purporting to come from you could in fact be coming from someone else.

Note on passwords: don't be afraid to write them down. Just be sure to guard that piece of paper carefully. Keep it with your credit cards, or your house keys, or something else that you're already accustomed to being careful with.

[Hamish Taylor]

Just worth noting that, while public keys are not confidential, people who are given a copy of your public key need some assurance that it really came from you, and not from somebody else. Otherwise confidential stuff they try to send to you could be readable by some unwanted third-party, and conversely confidential stuff purporting to come from you could in fact be coming from someone else.

Note on passwords: don't be afraid to write them down. Just be sure to guard that piece of paper carefully. Keep it with your credit cards, or your house keys, or something else that you're already accustomed to being careful with.

Hi Lawence

I am aware that giving too much information too quickly can lead to overload and is ultimately self-defeating. Encryption and security is such a massively huge topic that I am trying to break it up into bite-sized chunks! I will schedule another article about PKI trust and how to achieve that; probably after I go into S/MIME and X.509 as the the trust mechanisms are linked (kind of!). Thanks for pointing that out

Hamish

[redpox1st]

Top Quality article,
Pgp confused me as I didnt know how it worked with public and private keys but your article explained it perfectly for me and now it all makes sense!
Thank you for opening my eyes to something new
www.redpox1st.wordpress.com

[11vie]

cool thanks for sharing it..


assurance vie