Encryption for Arduino with Spritz

Hackaday.io user [Abderraouf] has written an implementation of the new(ish) Spritz cipher and hash for Arduino. While we’re not big enough crypto-nerds to assess the security of the code, it looks like it’s going to be pretty handy.

Spritz itself is a neat cipher. Instead of taking in fixed blocks of data and operating on them, it allows you to process it in (almost) whatever chunks it comes in naturally, and then extract out the encrypted results piecewise. It works both as a two-way cipher and as a one-way hash function. It looks like Spritz is a one-stop-shop for all of your encryption needs, and now you can run it on your Arduino.

In case you are afraid of new implementations of new ciphers (and you should be), Spritz’s pedigree should help to put you at ease: it was developed by [Ron Rivest] to be a successor to his RC4 algorithm, and it incorporates a lot of the lessons learned about that algorithm over the past. This doesn’t exclude subtle flaws in the implementation of the library (no offence, [Abderraouf]!) or your work downstream, but at least the underlying algorithm seems to be the real deal.

[Abderraouf] links it in his writeup, but just for completeness, here’s the Spritz paper (PDF). What crypto libraries do you currently use for Arduino or microcontroller projects? We’ve been fans of XXTEA for ages, but more because it’s simple and small than because it’s secure. Spritz may be simple enough to implement easily, and still more secure. Sweet.

Gritz: An Open Source Speed Reading Tool

Here’s a hack to help you increase your reading speed. Gritz¬†is an open source text file reader, which reduces the need to look around the screen. Words pop up one at a time, but at a configurable pace.

[Peter Feuerer] got the idea for Gritz from Spritz, a commercial product for speed reading. The creators of Spritz took three years to develop their software, and recently released a demo. They claim people can read at 1000 WPM using this technology. Spritz is taking applications for access to their APIs, which will allow developers to integrate the software into their own applications. However, a fully open source version with no restrictions would be even better.

Using Gritz, [Peter] claims to have read a book with a 75% improvement in his reading speed. He admits it’s not perfect, and there’s still much development to do. Gritz is written in Perl, uses Gtk2 for its GUI, and comes with instructions for running on Linux, OS X, and Windows. It’s released under the GPL, so you can clone the Github repo and start playing around with accelerated reading.

Potentially explosive spritz cookies

Do you recognize the shapes of these spritz cookies? Theoretical physicists and nuclear engineers might. They are representative of a hydrogen atom in several different states. Oh, and they’re delicious. [Windell] over at Evil Mad Scientist Labs cut his own spritz cookie discs in order to bake the hydrogen look-a-likes.

To bring you up to speed: spritz cookies are not rolled out and cut with a cookie cutter Рalthough you could print your own cutters in these shapes if you wanted to. Instead, a cookie press is used to squeeze out dough onto a baking sheet. The press looks like a very wide syringe. The dry dough is packed into a cylinder, and a ratcheting ram presses it toward the business end. A disc with wisely placed slits lets the dough squeeze out into the final shape.

We made some shamrocks for St. Patrick’s Day, but now we’re wondering if we can make our own Hackaday logo cookies. [Windell] grabbed some melamine dinner plates to use as raw material for his custom discs (remember to use food safe material). He then designed the cutouts in Inkscape and headed over to the laser cutter to fabricate the disc. We don’t have a laser cutter but we’d bet you can do a similar, but slower, job with a drill and a lot of filing/sanding.

[via Dangerous Prototypes]