A few weeks ago I installed DenyHosts, a small deamon (can also be run as a cron job) that runs on my server to block IP’s that make brute force SSH login attempts. The script has worked great, blocking over 500 hosts on the first day I used it (including myself a few times…). One of the features of the script is the ability to send an email each time it blocks a host. Although getting a few hundred emails at first was very annoying, setting up a few rules in gmail prevented me seeing them in my inbox (they go directly to a folder). I did, however, start to look at the times when the various hosts get denyed. They seem to come in large groups, so that there will be 50 or so hosts blocked in a rather short length of time, around 10 minutes or less. The IP’s of the computers also come from all over the world, but most seem to come from Asia, South America, and Russia. I think it would be interesting to do a more complete statistical analysis of the data in regards to the time and location of where the login attempts are coming from. Maybe I’ll write something to do this later.
December 27, 2008
A project that a friend of mine wants to complete is to build a small clock type device that can connect to the internet and show something like +/- 10% for the stock market (or a specific stock). The preliminary concept involves 2 physical devices and a program on the computer. The program on the computer will obatin the information on the stock performance from the internet, and format it into a percentage to be sent to the actual clock. The program will send the data to the first device, which will take the data from the program and send it wirelessly to the stock clock via a ZigBee controller. The second device, which is the clock itself, will then recieve the data and adjust the clock accordingly. The plan for the clock is to use a PIC microcontrollor to take the data from the ZigBee reciever and use the information to determine how to move the clock. The look we are going for is an analog needle type clock, so a stepper motor will be used to control the position of the needle.
Since we have just started working on this, not all the details have been worked out. My friend will be writing the computer software and the ZigBee transmitter; I will be building and programming the clock itself.
The choice of using ZigBee is to evetually allow multiple stock clocks to recieve data from the computer without needing to dramatically increase the complexity of the network. Plus, its a good excuse to use the ZigBee controllors that we already have.
I just purchased one of the PIC development kits that I have used before at a previous job, so once that comes in next week, I will be able to get started programming the microcontroller. I will eventually design a PCB and have one built for the final device. Updates will be posted once work actually starts.