[Peter] thought of a creative, way to generate random entropy for under $100.
The USB Hourglass combines a sand timer with a rotating mechanism and an optical beam through the center of the timer to observe the falling sand. The amount of light reaching a detector is digitized at frequent intervals and processed by a microcontroller to determine when to rotate the hourglass. The digitized light levels are also sent by USB to a host PC where they can be used as a source of random entropy. Power is supplied over the USB cable.
With the USB Hourglass, the user can look at the sand falling through the center of the hourglass and monitor the randomness in the USB output data. And one can read the code line-by-line, compile it, and upload it to the microcontroller using only open-source and widely supported tools.
[MS3FGX] has done an interesting study about using Bluetooth adapters as a source for Pseudorandom Number Generation (PRNG). As it turns out, the Bluez package has a function that calls a remote Bluetooth adapter to return a random number. He picked up 10 compatible adapters for about $30 from DealExtreme and set about assembling some numbers to see how this compares to an OS-based PRNG.
Because millions of samples are needed for an accurate comparison, time became a problem. The adapters are a little bit slow responding to a request, sending just 4800 numbers in the first 30-second test. This can be overcome with multiple adapters being accessed by multiple computers for hours at a time. What can this be used for? Your guess is as good as ours, but [MS3FGX] has done a great job of writing up his tests. He’s also made a set of 20.7 million randomly generated values available if you want to generate your own statistical analysis.
[Scott] runs gamesbyemail.com. One of his biggest hurdles was producing real random numbers for the games. He had tried various methods like math.random and random.org, but kept getting complaints about the quality of the random numbers. His solution was to build an automatic dice roller. His initial attempts were made from Legos and were never quite reliable enough to be put into the system. The Dice-O-Matic however has proven to be a random number generating monster. It is 7 feet tall and capable of 1.3 million dice rolls per day. Wow.
[aballen] wanted to light the jack-o’-lantern this year with something that didn’t actually require fire. After searching for a project that was cheap and yielded decent results, he ended up just making his own. This project utilizes an ATtiny13 and two LEDs, red and orange. The overall build is quick and simple with some very basic code for the flickering. If you really want it more enclosed, there is this similar project using a cheap electric candle. Of course, not everyone has the time or desire to make one that is this realistic. You could always just go the easy way, no microcontroller required.
Why limit it to just lighting up your pumpkin though? Lets take a stroll through Evil Mad Scientist Laboratories hallways and see the Snap O Lantern or the dark detecting pumpkin and the Cyclonolantern.
What is it about pseudo random flashing LEDs that make us go gaga? We don’t know, but there’s definitely something there. [seligtobiason] has this obsession too. After seeing several more complicated projects, he created this elegant, simple, and cheap piece of art. The entire thing is pretty much just some flashing LEDs, some resistors, and a power supply. It really isn’t anything groundbreaking, but the effort and cost involved are tiny compared to some other similar projects. sure, it doesn’t synchronize over time based on input like the firefly project. But for a quick cheap project, the results are quite nice.
We would put one in our home, right next to the node blinky.
AppleInsider is reporting that iPhone Software v2.0 will add a secure wipe feature. The screenshot above shows the text “This will take about an hour.” added to the normal erase feature. This time is used to overwrite data to the disk multiple times. The need for secure phone erasure came to light after a researcher was able to recover personal information from a refurbished iPhone using forensic tools. Since then, a few people have published techniques for obliterating personal data using either the GUI or the more thorough command line method. Remote wipe has also been added to the new firmware in case the phone is stolen. We’re happy to see security being made easily accessible to nontechnical users and expect that remote wipe will become standard on laptops in the future.