Older blog entries for MichaelCrawford (starting at number 58)

Congratulations Canada, on getting a twenty-four hour clock.

My name is Michael, and I'm a caffeine addict

Bonita got the idea that it would be soothing to her jangled nerves if she started drinking decaf instead of regular coffee. Things were in fact more pleasant for her the very first day off caffeine.

In part to be supportive and in part out of convenience I started drinking decaf too. I cut out the caffeine cold turkey.

It happens that I have always had a powerful thirst. I always have a beverage at hand and I'm always drinking something. So if a pot of coffee is on I will drink it until it's gone. (Unquenchable thirst is a symptom of diabetes - I've been tested several times and don't have it. It just seems to be the way I am).

So it turns out that when we brew a pot, Bonita will have one cup of coffee and I will drink the whole rest of the pot. So I have been drinking about three pots of coffee a day for quite some time.

So yesterday around 5 pm I lay down for "a little nap". I just wanted to take a little break before setting into some difficult work.

Bonita tried to wake me but I was so exhausted I could not get up. I slept until 9 am this morning. So my little nap lasted 16 hours.

When I lay down for another little nap this afternoon Bonita got really concerned. After some discussion we decided that the decaf must be my problem.

We went out to the local bookstore cafe and I had a large coffee and then another with a shot of espresso added. Caffeinated.

When I got home I had the energy to work and in fact fixed a difficult problem I've been working on for a few days.

Bonita feels that she doesn't need to cut out all caffeine, just most of it, so she had me brew a pot of regular coffee to drink while I worked.

I find it disturbing though that skipping caffeine for a couple days could have had such a dramatic effect. I think I want to continue trying to cut down on my caffeine.

I just don't think I should try to do it cold turkey.

Ice Nine

Greetings from Sunny Nova Scotia.

Really, it was bright and clear driving up today - and about 25 below zero celsius with blowing wind. Bitter, bitter cold.

Someone told Bonita yesterday that this is the coldest winter in Maine in ten years. We believe it.

It snowed a couple weeks ago but hasn't warmed up enough for it to melt in the slightest, so the snow is still powdery. It was drifting across the road today like fine sand. Even though it was sunny the snowplows were out clearing the edges of the road.

I only got about two hours sleep last night because I was preparing for the trip. So I won't work tonight. But tomorrow I'm going to huddle in the motel room and work on my laptops.

I have to keep this brief because I'm dialed into my Maine ISP long distance.

I'm very close to having the passphrase application for FireWire Encrypt working on Mac OS 9. There is documentation and sample code for doing FireWire on OS 9, but the doc is very terse and the sample code is very complex, and doesn't quite apply to what I'm trying to do.

I have all the code written that I think should be necessary, but it is not working quite right.

I got the Windows driver development kit so I could learn to do FireWire on Windows. After I do Windows (which I expect to be my most difficult platform) I will do it on Linux. I run Slackware on a Pentium III box and Debian Woody on my Power Macintosh 8500, so I can support Linux for both x86 and PowerPC.

This will be WiebeTech's first product with explicit Linux support. It's happening mainly because I'm into Linux, and I reasoned with my client that Linux people are more security conscious and so disproportionately likely to be interested in the product.

While you can get free hard disk encryption with the GNU/Linux Crypto API, installation and configuration are somewhat daunting. I figure we'll make some Linux sales because our product is easier to use.

Bonita and I are going up to Nova Scotia for a few days. I hadn't expected to go, but Bonita was worried about driving by herself because our winter has been fierce at times and it's very, very cold right now.

So once I'm done with this diary entry I'm going to get both my laptops prepped to work on the road (I have a 450 MHz Pentium III Compaq Presario 1800T and a 700 Mhz OS X/OS 9 iBook.

The Compaq used to be my main development machine. I bought it just before I moved to Newfoundland, and found it very handy when I was traveling around so much. But Bonita needed a machine so I took all my whacky stuff off of it and configured it the way she likes it. I only get to use it when I travel nowadays.

mobius said:

I'd also forgotten how ugly the Advogato layout is. Yick.

That's funny, because I regularly point out Advogato to my friends as an example of particularly tasteful web design.

Someone emailed me just now to tell me that a google search for how to get ranked on internet turns up my article How to Promote Your Business on the Internet as the number one search hit, ahead of 551,000 other pages.

Me: Did you know that X-rays and gammar rays are just light? They're just higher frequency light.

Bonita: You say the sexiest things.

Happy News!

It seems that the firewire encryptor I wrote for WiebeTech is being enthusiastically received at the MacWorld Expo. There is every sign that my hard work and my client's investment will result in a commercial success.

Bonita and I are very excited about the news, as I imagine my client must be.

I issued my first press release ever, and have been faxing it to newspapers around Maine:

There is news coverage about FireWire Encrypt at MacObserver and MacCentral.

I think MacObserver was confused when James called the passphrase interface an "applet". In their article they call it a "Java applet". It's actually written in C++ and is a vanilla carbon application; we call it an applet because it so simple. I used ZooLib so I can make the UI for Windows and Linux from the same sourcebase.

7 Jan 2003 (updated 7 Jan 2003 at 01:44 UTC) »
Embedded Systems Development

So Nate Myers emailed me today to ask why I didn't just post a web page with the text of WiebeTech's press release about the product I developed for them instead of all these cryptic hints in my diary.

And I responded to Nate that his email was the first that I'd heard of WiebeTech announcing the product, and I didn't want to announce it before WiebeTech did.

(WiebeTech's press release is a Word document. Sorry. I'll ask them if it's OK that I post an HTML version.)

WiebeTech's FireWire Encrypt(TM) is an implementation of the Advanced Encryption Standard embedded in an Oxford 911 FireWire/IDE bridge. It encrypts each sector of the user's hard drive using the Rijndael block cipher.

It is designed to be portable and easy to use. Easy to use because the only software the user needs to install is a small applet to enter the passphrase. There is no complicated operating-system level software to install or configure. Portable because FireWire is a hot-pluggable technology for external devices.

A good use for the product would be to safely take confidential source code or business plans home from work on a hard drive, without fear that your secrets would be revealed if the hard drive were stolen.

WiebeTech will be demonstrating it on Mac OS X, but I plan to support it from Linux and Windows by the time the product is released to the public.

And yes, we're applying for a patent. But we're not applying for an algorithm patent. I disagree as much as anyone here with the abusive patents that the USPTO has been issuing the last few years, but I think this sort of thing is appropriate to patent.

Getting it to actually work was definitely novel and unobvious, and I believe that users will find it useful.


Someone emailed to ask me about what encryption mode FireWire Encrypt uses, and I thought I should post that here too.

It uses Cipher Block Chaining and Initialization Vectors.

Cipher block chaining is applied to each 16-byte block of a 512-byte disk sector. What you do is XOR the previous block's ciphertext over the next block's cleartext before encrypting subsequent blocks. This has the effect of making identical blocks of cleartext encrypt differently.

CBC can't be carried between disk sectors because the host can read or write each sector independently. To make identical sectors encrypt differently, I use an initialization vector.

What you do is XOR some value over the first block of cleartext in each sector before you encrypt it. The IV doesn't have the be kept secret. It doesn't even really matter what value you use, as long as each sector gets a unique IV. The simplest thing to do is to use the sector number as the IV.

I felt that was the best thing to do after reading about block cipher modes in Bruce Schneier's Applied Cryptography.

Initialization vectors work better than you might think because one of the characteristics of a strong encryption algorithm is that flipping a single bit in the plaintext will flip, on the average, half the bits in the ciphertext, with the bits that get flipped being apparently randomly distributed. So having only one bit of the IV being different from sector to sector will dramatically change the ciphertext.

I was also asked if the product checks that the user has entered the correct password. The version that will be demoed at MacWorld doesn't do that yet, but I think that verifying the password is very important for making the product accessible to regular users. I know a simple way I can do that, and plan to check passwords in the final released product.

Embedded Systems Development

Well I got my product ready for MacWorld. I delivered the show build at 9:30 am this morning. Fortunately my client didn't have to fly out to SFO until this afternoon, so he was able to install and test it. He said it worked well.

If you want to see what I've been working on, stop by WiebeTech booth #1651 and ask James to show you the "technology demonstration".

I pulled all nighters two nights in a row to make the show deadline, with only four hours sleep in the middle. That's starting to get hard on an old guy like me. (I'm 38. I wouldn't have thought that was too old to stay up all night but it's starting to feel that way).

I'm glad I delivered a test build last night for my client to try out before the final delivery, because he had some trouble and I had to figure out what was wrong. We were planning to stay up all night while I sent him diagnostic builds but fortunately it was just a couple simple problems that didn't take us long to figure out.

I was really worried though because what he tested wasn't really of good enough quality to demo at a trade show, and I was worried sick some awful bug would happen. But in the end everything went well. It took all night because there was a lot of work to do but there were no real problems encountered.

In the end I was able to just deliver the demo and go to bed, and my client was able to run it just fine.

Some work remains before the product can be made an end-user product, but I know how to do what needs to be done. One of the chief advantages of my product over competing products will be that it should be so easy for regular users to use. It's not quite there yet.

Now I wait anxiously to hear what the reaction from the press and the public will be.

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