Public Key Authenication

I’m a sucker for simple explanations. I mean sure, all those fancy words might make people seem more intelligent, but when it comes to my understanding-ness, the simpler — the better, especially when starting out.

I admire people who can bolt themselves down and wrap their brains over one concise/precise paragraph riddled with tech jargon and make it to breakfast the next morning. Its a gift I guess, looking from it from my point of view, as I can never - and could never - do that. My best performance when faced with tech explanations (hello man pages) is mugging it up. Can’t understand it? No problem, mug that sucker up good.

This is a fundamentally flawed method of education. Unfortunately, my schooling is partly to blame for encouraging such behavior. And old habits are extremely difficult to unlearn.

However, new ones are sometimes not-so-difficult to grasp. And in my ever looping quest for gaining new knowledge, one thing I’ve realized to be friend is good old simple English language. Structured just precisely enough to make it layman-proof, yet not overdone to the point of boring him/her.

So today, I chanced upon a wonderful write up for what a public/private encryption actually is! Here are some possible dilemmas for newbies who want to learn about it.

  1. Google it - Sometimes those pageranked pages dont cut it for what you’re after.
  2. Read a book about it - I just want to know one concept, do I really have to read an entire book to understand it? Further, do I really want to?
  3. Ask a friend - Hard if both your understandings are on different levels.

Sometimes you will just trip over the most wonderfully written piece of relevant literature; out of pure dumb luck.

Without further fuss, I present to you what delighted my day.

===

Public key authentication is an alternative means of identifying yourself to a login server, instead of typing a password. It is more secure and more flexible, but more difficult to set up.

In conventional password authentication, you prove you are who you claim to be by proving that you know the correct password. The only way to prove you know the password is to tell the server what you think the password is. This means that if the server has been hacked, or spoofed (see section 2.2), an attacker can learn your password.

Public key authentication solves this problem. You generate a key pair, consisting of a public key (which everybody is allowed to know) and a private key (which you keep secret and do not give to anybody). The private key is able to generate signatures. A signature created using your private key cannot be forged by anybody who does not have that key; but anybody who has your public key can verify that a particular signature is genuine.

So you generate a key pair on your own computer, and you copy the public key to the server. Then, when the server asks you to prove who you are, PuTTY can generate a signature using your private key. The server can verify that signature (since it has your public key) and allow you to log in. Now if the server is hacked or spoofed, the attacker does not gain your private key or password; they only gain one signature. And signatures cannot be re-used, so they have gained nothing.

===

And where did I find this? In the freaking manual of the software I was using. With this basic explanation out of the way, all the other stuff that I had learnt that was built ON TOP of the supposition that I had understood this, all start falling into place.

Cheers.

Installing Natty Narwhal on Thinkpad T410

I had this sudden urge to try out the latest Ubuntu while fiddling around on Win7. By try out I mean wipe my hard drive and do a clean installation (as has been the ritual for most Ubuntu releases). That and I’m really craving to go back to 64-bit computing as my Thinkpad came installed with Win7 32 bit (which I found to be a bit slow for my needs), and my plan to upgrade to 8 gigs was foiled by this numerical aberration. (educational link)

The backup process took longer as I took a couple of liberties to allow for facilitating this viscous cycle of re-installments easier. Like tar-ing directories with lots of files on them so that they transfer faster as one huge file than a thousand tiny files.

Needless to say, this took a big chunk of my time, and finally when all was done, and the disk was burnt, I couldn’t hold back my enthusiasm when I put it in and restarted my laptop.

Straight off the bat, I was glad to know my wireless worked. I have almost always spent an additional 4-10 hours trying to get the wireless up after a new Ubuntu/*nix install. The live demo worked wonderfully and I was looking forward to burn it down onto my HDD!

I also liked how at the beginning of the installation process it gives us a choice to install those closed-source codecs like the ones for mp3 and adobe flash. Way to make it easier guys! :D

Unfortunately, the ride was not so smooth after all. Towards the end of the installation, I got a kernel panic and everything froze up on me. This was when I tried the live cd and chose to install after that.

One reboot later, I chose to install without going through trying out the demo. The kernel panic happened at the same time as before, but this time, my screen was replaced with a terminal full of cryptic messages! Worst part is since this occured AFTER the HDD format step, I didn’t have good ol Win7 to help me out of this.

Luckily I had a copy of Ubuntu 9.04 (its been two years already!), I think its Lucid Lynx, and I pop that in to see if it works, and joy oh joy, it does. And it installs fine as well!

So after that installed, I was obviously not pleased so decided to see if I’d get an upgrade option with 11.04 in the cd-drive. Which it didn’t, and the only options I had was to a) stick with 9.04 b) back to Win7 32, c) Give 11.04 one more try, third time lucky.

I went with option c, and quite glad I did. This time round however, I flicked the wifi switch on my Thinkpad off. I’d caught something about the wifi when the installer crashed second time around, and on a superstitious hunch, turned it off.

It installed without a hitch!

I googled for this problem, but didn’t hit any results, so I decided to whip up a summary/blog post to hopefully help someone else who has been in my dilemma.

Cheers and enjoy your Natty. (This name reminds me of the worst beer ever. Hopefully the release is better :)).

The Apple of my I

I’m a fan of a lot of things Apple, especially when it comes to UX and usability and nifty little why-didn’t-anyone-else-think-of-that features (like the physical phone vibrate button on iphone) or great software integration between native iOS apps (iLife).

But…

Somewhere in all this wonderland there is a black goat rampaging about that kinda gets me really annoyed.

Enter, iTunes…

Scenario:

I have an iPod Touch. I want to put songs on it. I run Windows 7.

Problem:

There is no straight way in hell that I can just use it like any other portable device I own. Sure, there are ‘hacks’ to get winamp to recognize the device and ‘talk’ to it correctly (which i did try but in vain), but no. Someone in Mr. Job’s department (or maybe Steve himself) decides that their fragile iPod cannot be handled by anything else except their homegrown software.

Which in itself is The ‘Kalank’ in Apple’s name.

Solution:

Install iTunes……. reluctantly. Just so I can transfer ONE album to the iPod.

iTunes slyly installs QuickTime along with it which, honestly Ive never had to use. Ever. And the nerve of the programmer who decided that quicktime needs its own little helper program to run EVERY TIME THE COMPUTER STARTS.

My goal of transferring that album to my ipod is still unnattained, but hey, I can try to view my videos in quicktime which will try and tell me I’m stupid and have to buy their pro version.

So I fire up iTunes….. again very reluctantly, keeping an eye on my resource monitor. There goes my ram. Given Windows manages memory with dynamic allocation, it still is a shitload of Ram if it allocates 40% to iTunes alone (compared to 3% for WinAmp). Mother of apple eating worms, I can’t imagine any way this stupid app is going to increase my anger any more.

Until I wait for it to read my 60GB library, then click on my iPod name, only to be warned that my existing collection on the iPod will be wiped if i sync (cuz i used another computer to carefully handpick my songs from there onto the iPod).

And if iTunes was even a half decent jukebox I wouldn’t mind using it and tweaking around so that I could save my current songs from iTunes AND upload new ones. All it is is Apple’s storefront. Its not even a jukebox! Its a SHOP disguised to look as a jukebox.

So I ended up NOT transferring that album, uninstalling iTunes and QuickTime, cussing Apple a thousand times in between, and writing this rant :)

Thanks for reading. Please send the hate-mail to idontcare@gmail.com

1 2 3