Archive for 2012

Season's Greetings

Submitted by PurpleAlien on Fri, 12/28/2012 - 03:06

Tags: Other

It's that time of the year again, where it gets really cold and dark (at least in Finland it does) and you gather around with friends and family for food, drinks and fun! However, once in a while you need to take a little break and get some 'fresh' air. We had a really nice clear sky - so I took the picture below with my HDR-CX700 without tripod, and in -20 degrees Celcius. I think it came out nicely, although I did seem to have a bit of dirt on the lens or something... anyway, will try again with a proper tripod later.

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Back home

Submitted by PurpleAlien on Thu, 10/04/2012 - 16:21

Tags: Computer, Electronics

A couple of days ago I returned home from an extensive trip abroad. After getting some needed rest it was time to get back in the home office and start running some updates on my computers. I've got one older Sun Microsystems Ultra-20 workstation which I still use extensively. It's definitely not the fastest machine on the planet, but it gets the work done.

Ultra 20

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Kids these days...

Submitted by PurpleAlien on Thu, 08/30/2012 - 07:52

Tags: Embedded, Programming, School

Recently I've noticed an increasing amount of questions in several LinkedIn groups I joined regarding people new in the field asking questions which are easily found using a basic internet search. Furthermore, we have students and others ask questions with regard to degrees and experience in the field. After replying to dozens of posts like that, I thought it would be good to condense the information spread across several groups into one blog post as a reference for future questions.

While the groups in question are particularly focused on embedded engineering, operating systems and software engineering, I assume similar posts are present in other groups. Hopefully, some will find their way to this blog and find the information in this post useful. I'm sure this phenomenon isn't limited to LinkedIn groups either...

Men in Black Orange

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Dealing with Passwords

Submitted by PurpleAlien on Fri, 06/29/2012 - 05:57

Tags: Cryptography, Programming, Security

After the recent leaks of password hashes from LinkedIn and others, I thought it would be a good idea to write down some 'best practices' in how to properly deal with user passwords and sensitive data. This entry is by no means complete, nor is it the be all, end all there is to say about the topic. What it does try to do is give a decent starting point to eliminate basic mistakes which could lead to embarrasment later one. If you're developing a new website, or bringing another one up to date or are otherwise working with users and passwords, these tips might be of help. Let's start...

X-Ray Key

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LinkedIn leak

Submitted by PurpleAlien on Sat, 06/09/2012 - 20:37

Tags: Cryptography, Security

So LinkedIn had some security issues a couple of days ago: 6 million or so password hashes from their users were leaked on a Russian hacker site. There seems to be quite some confusion among people as to what the impact of this really is, with several websites claiming that the actual passwords were leaked, that the passwords can be 'decrypted' etc. Let's put some of these things straight, starting with some of the terminology.

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The Cloud...

Submitted by PurpleAlien on Fri, 05/25/2012 - 02:33

Tags: Cloud, Network

It seems like everyone and their dog is talking about The Cloud these days. For many, it appears to be some magical concept that will revolutionize the way we use computers, tablets and mobile phones. Everyone is in awe about something, but few people can actually describe what that cloud thing really is...

 Little Green Men

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Porting wpa_supplicant

Submitted by PurpleAlien on Thu, 03/29/2012 - 05:51

Tags: Network, Programming, Wireless

If you've ever tried porting wpa_supplicant to a different operating system, you probably have come across this link on the wpa_supplicant documentation page: Porting to different target boards and operating systems. While it gives a good heads up, the end section describes the C files needed to build an initial compiling version from where to start building the operating support.

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San Antonio Storm

Submitted by PurpleAlien on Thu, 03/22/2012 - 05:43

Tags: Lightning, San Antonio

We had a pretty decent storm here in San Antonio a couple of days ago. There was even a tornado warning for a while, and while it touched down 25 miles southwest of San Antonio on Monday evening, it did not hit the city itself. Some 50 homes were damaged in the surrounding area of Medina, Texas, and several people got injured.

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An Introduction to Elliptic Curve Cryptography

Submitted by PurpleAlien on Sun, 02/19/2012 - 10:51

Tags: Cryptography, Mathematics

Some of my research is focused on the implementation issues of Elliptic Curve Cryptography on embedded systems. Since I often have to explain what Elliptic Curve Cryptography exactly is, I decided to write this little introduction on the matter. Maybe this will get the attention of some of my students, and can perhaps get them more interested in the mathematical branch of finite fields in Algebra.

Crypto logo

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Transparent Caching Proxy with Squid and Just One Ethernet Port

Submitted by PurpleAlien on Sun, 02/19/2012 - 09:07

Tags: ARM, Efika, Linux, Network, Squid

Some time ago we had a project which needed a simple transparent caching proxy for use in classrooms in Latin America. The classroom desktops consisted of ten of our Efika's, and we thought why not use an extra one of those to act as the proxy. This is not the kind of high bandwidth environment of a typical installation, so the performance limitations were not really an obstacle. The goal was rather to use the limited internet connection available as efficiently as possible. The configuration of the system using Squid is detailed below.

Efika NetTop

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