Quinn DuPont writes in with "A cracking challenge to cryptanalyse a William Gibson poem ('Agrippa', written in 1992). The winner will receive a copy of every William Gibson book published. Project is academic (non-commercial)."
Gibson's poem is a beautiful work, and it came on a floppy disk that erased itself after displaying the poem's text a single time. Of course, it was cracked almost immediately (..f. all DRM, ever) but that wasn't really the point. The challenge site includes a System 7 emulator, an image of the floppy, some of the sourcecode for the app (which was apparently written in Lisp?!), and more.
Based on the pioneering work of Alan Liu and his team at The Agrippa Files, working in collaboration with Matthew Kirschenbaum at the Maryland Institute for Technology in the Humanities and the Digital Forensics Lab, a a bit-for-bit copy of this application has been recovered, along with numerous archival documents.
The first person to successfully crack the code will win a copy of every William Gibson book ever published (except Agrippa). Every runner-up will have their name (if provided) posted on this website. To win you must submit a technical description of your cryptanalysis below, under Creative Commons usage rights (the results of which will be used to further research on Agrippa). The technical description should explain what kind of encryption is used (if any), how it functions, and how it was reversed or cracked (and what the key is, if there is one). Should there be no encryption at all (a possibility), or should the application merely “scramble” or “destroy” the data, this must be technically demonstrated or proved. Since the plain text is known, the cryptanalysis is purely for fun and academic curiosity, and thus the description should provide technical details.