Mitsubishi Corp. introduced a new form of authentication system this week. Introduced at a concert of a Japanese band called Rip Slyme, the technology replaces ordinary admission tickets. Instead, a two-dimensional bar-code was sent to the mobile phone of those who had won free admission to the concert. Special bar-code readers were installed at the entrance of the live concert.

More information:
AsiaBizTech (english)
Mobile-Symbol.com (japanese)
Planet Multimedia (dutch)

This new technology raises a few questions with me: first, how hard can it be to copy a two-dimensional image on an LCD screen? I'm not sure whether there was one specific code sent to all phones, or if there was a different code for each participant. Both have downsides, though: If Mitsubishi uses one code, you only need one leak to have everyone be able to get passed those scanners. If you use multiple codes instead, the chance of guessing a code, using random generation, increases. I wonder, how many different combinations would be practically possible? What's the resolution of a I-pod screen, and at what resolution do those scanner scan without failures?

Anyway, it's still an interesting technique. I wonder if it's going to be implemented in other validation-systems (think train-tickets and the like) as well.