DIY Punch Card System Despite Hanging Chads

Sometimes you just have parts lying around and want to make something out of them. [Tymkrs] had a robot paper cutter, so naturally they made punch cards. But then, of course, they needed a punch card reader, so they made one of those too. All with stuff lying around the shop.

The Silhouette Portrait paper cutter is meant for scrapbooking, but what evokes memories of the past more than punchcards? To cut out their data, rather than cute kittens or flowers, they wrote some custom code to turn ASCII characters into rows of dots. And the cards are done — you just have to clean up the holes that didn’t completely cut. These are infamously known as hanging chads.

The reader is made up of a block of wood, with a gap for the cards and perpendicular holes drilled for LEDs and photoresistors. This is cabled to a Propeller dev board with some simple firmware. We would have used photodiodes or phototransistors, because that’s what’s in our junk box (and because they have faster reaction time), but when you’ve got lemons, make lemonade.

OK, now that you’ve got a punch card reader and writer, what do you do with it? Password storage comes to mind.

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A better way to hack iClass RFID readers

iClass is an RFID standard that is aimed at better security through encryption and authentication. While it is more secure than some other RFID implementations, it is still possible to hack the system. But initial iClass exploits were quite invasive. [Brad Antoniewicz] published a post which talks about early attacks on the system, and then demonstrates a better way to exploit iClass readers.

We remember seeing the talk on iClass from 27C3 about a year and a half ago. While the technique was interesting, it was incredibly invasive. An attacker needed multiple iClass readers at his disposal as the method involved overwriting part of the firmware in order to get a partial dump, then patching those image pieces back together. [Brad] makes the point that this is fine with an off-the-shelf system, but high-security installations will be using custom images. This means you would need to get multiple readers off the wall of the building you’re trying to sneak into.

But his method is different. He managed to get a dump of the EEPROM from a reader using an FTDI cable and external power source. If you wan to see how he’s circumventing the PIC read protection you’ll have to dig into the source code linked in his article.

2708 EPROM dumper

[Andrea “Mancausoft” Milazzo] has been restoring old equipment which often contain EPROM chips. He thought he was all set with an EPROM reader which easily dumped the data from 2716 chips and a few others. But he found that the hardware was unable to read 2708 and 2704 chips. His solution was to build a PIC-based EPROM dumper.

You may remember from some of our recent features that these chips are something of a ticking clock. They store program code and other information vital to the functioning of old hardware. Since they’re erased with UV light, years of exposure to ambient light can zap some of the data.

The specs needed to read a chip of this type are rather rudimentary. There are ten address pins and eight data pins. [Andrea] also needed a way to get data from the microcontroller to a computer for backup. He uses two more pins for this purpose, bringing the I/O count to 20. He went with  PIC 18F4610 and built the rest of the reader around it.

RFID reader gets user inputs and smart card write capability

[Navic] added a slew of abilities to his RFID reader. It’s now a full-featured RFID reader and smart card writer with extras. When we looked at it last time the unit was just an RFID and smart card reader in a project enclosure. You could see the RFID code of a tag displayed on the LCD screen, but there wasn’t a lot more to it than that.

The upgrade uses the same project enclosure but he’s added four buttons below the display. These allow him to access the different features that he’s implemented. The first one, which is shown in the video after the break, allows him to store up to six tags in the EEPROM of the Basic Stamp which drives the unit. He can dump these tag codes to a smart card (pictured above), but also has the option of interfacing with a PC to read from and write to that card.

We don’t think you can directly write RFID tags with the device, but we could be wrong.

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Keep your kids in line with a time clock

When the cat’s away the mice will play, but a least you’ll know when they came home if you use this time clock. It’s called the Kid-e-log and [John Boxall] developed it to help a friend who wanted to keep track of their teenage children’s after school activities while they were still at work. He figured having them punch a time clock would at least let you know if they came straight home as they were supposed to. An RFID tag was issued to each (no, they didn’t implant the tags) and used to record the time. To keep fraud to a minimum the hardware has a battery back-up for its real-time clock, and the tag read events are stored to EEPROM for retention between power cycles. This doesn’t prevent common tricks like taking the reader with you, or sending your tag with a sibling, but it’s a start. See it in action after the break.

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Cheap(er) biometric gun safe

[Greg] sent in his biometric pistol safe lock. He keeps his guide light on details so not every Joe can crack the system (there is a thread to sift through if you really wanted to), but the idea runs fairly simple anyway. [Greg] took an old garage door opening fingerprint scanner and wired it into a half broken keypad based pistol safe. While he did have some issues finding a signal that only fired when the correct fingerprint is scanned, a little magic with a CMOS HEX inverter fixed that problem quick.

This does bring one question to our minds, are fingerprint scanners as easy to crack as fingerprint readers?

RFID readers, writers, and spoofers

[Carl] has done a lot of work developing a collection of RFID hardware. The two cards you see above are spoofers that can be programmed in the field using the keypad on the left, or the rather intimidating banks of DIP switches on the right. We also enjoyed his look at the Atmel T5557 and ATA5567 on-card chips used for the tags themselves. He shared the schematics for his designs but unfortunately he’s not distributing the firmware. None-the-less, if you’re interested in learning more about RFID this is a wonderful resource as it covers readers, writers, spoofer, and tags.