Wednesday, August 30, 2006

Rocket Plane Racing !?

Flash Gordon is real.

While reading the new Tech Topics Ga Tech alumni magazine this morning I learned that there are companies like XCOR who are making commercial rocket planes! Yes, their intention is to use them for suborbital flights. And they also race them in the Rocket Racing League! Here's a cool video of a plane.

Tuesday, August 29, 2006

Holographic Poster from Terminator 2

Okay, this is just cool: a holographic poster from Terminator 2.

Google Revealed

Information Week has an interesting article, Google Revealed: The IT Strategy that makes it work. It includes interesting side bar articles as well.

Google has between 200,000 and 450,000 servers spread among up to 65 data centers, depending on how you define them and who's doing the counting. And those numbers continue to rise.

Google organizes its machines, which run Linux, into ‘cells,’ which DiBona describes as a kind of disk drive for Internet services. (Not to be confused with Gdrive, the long-rumored Google hosted storage service. ‘There is no Gdrive,’ a spokeswoman insists.) Software programs reside on racks of inexpensive computers, and programmers decide how much redundancy to give them. The cells take the place of commercial storage equipment; DiBona says Google's cells are cheaper to create and maintain, and he hints they can handle more data, too.

(The underline/bold is mine).

Top 500

The Top 500 is a web site and project that...

The TOP500 project was started in 1993 to provide a reliable basis for tracking and detecting trends in high-performance computing. Twice a year, a list of the sites operating the 500 most powerful computer systems is assembled and released. The best performance on the Linpack benchmark is used as performance measure for ranking the computer systems. The list contains a variety of information including the system specifications and its major application areas.
Here's The Current June 2006 List of top 500.

Sunday, August 27, 2006

Freenigma Encryption Plug-in for Gmail!

Here's a GPG-based encryption plugin for Gmail (and others) from Freenigma!

Equinix Co-Location Center Tour on Cnet

This is an interesting “tour” of a data center belonging to Equinix. The article and tour make it sound like all Internet companies use Equinix for their data storage, etc., but I don't believe that is true. What is probably true is that this is one of the data center co-location providers that many of them use.

The tour spends most of it's time focusing on power, and touches a tiny bit on cooling and security. It doesn't mention networking at all, etc.

Still, it's interesting if you aren't familiar with facilities like this, and entertaining if you are.

Friday, August 25, 2006

Amazon S3

I guess I'm behind or not paying enough attention. I didn't really know about Amazon S3 from Amazon Web Services. Actually I vaguely recall pointers and news notes, but didn't follow up on them.

So that makes one wonder, does Google plan to offer a similar form of web storage? It didn't take much searching to turn up rumors of GDrive:

Whoa! Amazon Elastic Compute Cloud (EC2)

Get a cluster of Linux servers from Amazon, on the fly, as needed. This is amazing! The cost is 10 cents per machine-instance hour!
You have complete control of your instances. You have root access to each one, and you can interact with them as you would any machine. Each instance predictably provides the equivalent of a system with a 1.7Ghz Xeon CPU, 1.75GB of RAM, 160GB of local disk, and 250Mb/s of network bandwidth.

Wednesday, August 23, 2006

Nice IBRIX Document

Since we are looking at the IBRIX file system for the new HPCC (high performance computing cluster), here's a nice document from HP on IBRIX.

Monday, August 14, 2006

OpenSSH Key Management

Here is a set of three articles which do a decent job of explaining OpenSSH and key management.

How Does SecureID Work?

Here's one explanation I found which seems adequate.

This was posted on Firewall Wizards, in the archive, by Vin McLellan (

Glad to help. All versions of the SecurID use RSA's patented
technology to synchronize the use of Current Time in a SecurID token and its remote authentication server, what RSA calls the ACE/Server. (Typically, as you know, the link between the token-holder and the ACE/Server is through an intermediary -- an ACE/Agent or RADIUS agent -- which intercepts an authentication call and relays it to the ACE/Server for processing.)

The classic SecurID, for 15 years, used a proprietary algorithm to hash a token-specific 64-bit seed and Current Time. The new SecurID -- introduced at the beginning of 2003 -- uses the AES block cipher, in standard ECB mode, to hash:

- a 128-bit token-specific true-random seed,
- a 64-bit standard ISO representation of Current Time
- a 32-bit token-specific salt (the serial number of the token), and
- another 32 bits of padding, which can be adapted for new functions or additional defensive layers in the future.

Conflated and hashed by the AES, these inputs generate the series of 6-8 digit (or alphanumeric) token-codes that are continuous displayed on the SecurID's LCD, rolling over every 60 seconds. (The standard mode of use, as you know, requires two-factor authentication: the token-holder is required to provide both a SecurID token-code and a user-memorized PIN to the remote ACE/Server.)

ECB mode in AES is executed on 128-bit blocks, of course, so it is obvious that RSA had to pad the standard 64-bit expression of Current Time with another 64 bits. Using a token-specific salt blocks any attempt to pre-calculate a library of possible token-codes for all 128-bit seeds. That means that any brute-force attack on the AES SecurIDs would have be focused on a particular token.

Friday, August 11, 2006


When someone asked me a question about udev the other day, I realized I didn't know much about it. I had recently finished the Linux kernel driver book so I thought I should have remembered something. Looking back at the book, I found that the book predates udev and so I really hadn't read anything about it (other than references at LWN and such).

So I went to the udev web site and read the OSL 2003 paper (pdf), which explains udev nicely. I strongly recommend reading it!

IBM PC Birthday

The IBM PC is 25 years old on 12 Aug 2006. Remember how the lowest-end models came with a cassette player interface (for saving programs onto tape) and booted directly into BASIC. You could get one or two 5.25-in floppy disk drives which, I'm sure, is how most models were sold.

Thursday, August 10, 2006

MP3s in my Car

Okay, it's probably a sign of age but walking around with permanent ear buds is something I just can't get into. Maybe I'll get there some day or maybe not.

I listen to music in mainly two environments: (1) at my desk (home and office) and (2) while driving. The first of those has been well taken care of for a long time. It's the second one that's the problem now. I'd really like to avoid carrying around CDs in the car, even copies of my CDs, so that's where I need an MP3 player.

Thus my real question is, why do I need a cassette adapter (which isn't an option since my car only has a CD player) or FM transmitter (which I haven't read anything good about)? Why can't I just adapt an MP3 player directly to my car system? All MP3 players have line-level outputs and I'm sure my car has line-level inputs. In fact my car has an auxiliary input for a CD changer and an AX (aux) button on the panel.

Well, I just came across this site,, which looks promising.

TV Interview with Mark Shuttleworth

Here's a TV interview with Mark Shuttleworth. Oh, he's the creator of Ubuntu.

What is Space?

Over the years I've observed that people are often confused about how space and astronomy are used as categories. Obviously they are related and pretty much overlap. However, in popular usage, they refer to fairly different things.

Space is a place you go. It describes an enviroment and is occupied by an industry, mostly government-based, that involves engineering, rockets, satellites, spacecraft, and such.

Astronomy is a science. It's the study of things above the earth's atmosphere (well, okay, things in space). Astronomy involves scientists, telescopes and observatories, theories, data and computer programs.

You could make a good case for the distinction being artificial, but it is real. Space and astronomy involve two very different cultures, in the same way that physics and astronomy are two different cultures, although most astronomy is physics.

James Van Allen

(Dr. William Pickering (director of JPL), Dr. James Van Allen, and Dr. Wernher von Braun holding up an Explorer 1 model, the first successful satellite launched by the US on 31 Jan 1958).

James Van Allen dies at age 91. One of the original space pioneers, his Van Allen Belts were big news about space when I was in elementary school.

I didn't realize his involvement in the International Geophysical Year (1957) which the NYT article says was “born in his living room in Silver Spring, Md,” in 1950.

Wednesday, August 02, 2006

Curt told me about this cool web site,, which links to and allows users to rate tech-type articles. The voting/rating system makes this a very interesting resource for reading.

They say
Digg is all about user powered content. Every article on digg is submitted and voted on by the digg community. Share, discover, bookmark, and promote the news that's important to you!
Fascinating idea!

Arizona Highways Photography

Wow!! Amazing photos are at Arizona Highways. I found this while reading this interesting article on digital camera resolution.

Blackjack! ...21 Years

I missed it! Yesterday was my anniversary of 21 years at Emory. I'm not sure what to think about that…

Hello Ubuntu, Good-bye Red Hat?

In his article, Why Red Hat will go bust because of Ubuntu, Tony Mobily predicts the demise of the Microsoft of Linux. Discussion is on Slashdot. His story tracks my own experience precisely.

Tuesday, August 01, 2006


According to Clark Howard the sweet spot for HDTVs will be 32-in LCD at $500 this Christmas. All technologies (Plasma, DLP) will be under $1000 by then. Expect 32-in LCDs to be around $200 by the following Christmas (2007).

He also advises not to by hi-def DVD players for at least another year.