Paper Reading #9: The IR Ring: Authenticating Users’ Touches on a Multi-Touch Display

Comment 1: http://gspotblogspotblogspotblogspotblogspot.blogspot.com/2011/02/paper-reading-10-tag-expression-tagging.html
Comment 2: http://chi-jacob.blogspot.com/2011/02/paper-reading-9-ir-ring-authenticating.html

The IR Ring: Authenticating Users’ Touches on a Multi-Touch Display
Volker Roth, Philipp Schmidt, Benjamin Guldenring
User Interface Software and Technology

This article discussed the ideas and implications of being able to identify multiple and different users on a multi touch display through the use of infrared rings. The idea here is that, multiple users might be able to use the same multi touch surface and instead of having a complicated log in system the users would each be able to simple wear a ring and use that as their way to "log in". This also allows for an easy way to deal with security as users would only be able to modify files that are tied to their IR ring ID. They started by looking at the state of art which is to use the XWand which is an infrared pointer that works with two cameras in the room to help the user determine location. Essentially with this, systems can be set up to allow the user to turn off the lights with the XWand. They then discuss more implications of the security that can be provided by their system and the hardware components that would be needed to accomplish this. The infrared device itself works by sending a stream of psuedo-random bits to the screen, this is done through a process called a Manchester coding algorithm. The code not only sends the message of what the user is pointing at but also the users ID and the location of where they are touching and the different points of their action. This then gets sent to a swtich which determines if the signal is an input or a form of identification. It sends this data to a decoder that figures out the sequence of bits using the Manchester decoding algorithm and then sends this to a matcher which matches the users pattern to a series of known actions and determines what the user is trying to do. They then discuss the "poor mans" model of this that they have built and have been testing. While it is not as large of a scale as they want and they were not able to get the bit rate that they wanted they did consider this to be a rather good test. They did notice some unintended constraints such as the ring must be pointed towards the table or else the transmission rate would decrease greatly or not be able to transmit at all.

I think this is a really neat system but I don't understand its need right now and the article was overly technical for what it needed to be. Nearly a third of the article was discussing the specs of the hardware and it didn't really give a lot of ideas as to how it would be used or practical examples of what this kind of technology would be used for. I understand that this is likely a dissertation paper and needs to be written in a manner but I had a rather hard time understanding a lot of it. The idea of having a ring that a user can wear to help in authentication and security on a multi touch display is a really cool idea. If this could be expanded and we could simply have a user log into any computer system by having it scan their ring or a chip inside the person it would make authentication a lot more safe and much more efficient. I wonder what they plan to do to get the data transmission rate of the ring to go up. They compared it to the Wii mote and talked about how it was much faster and transmitted a lot more. I think that if this kind of system could take off we could add really cool personalized features to multi touch displays and it might help to increase distribution of multi touch devices on larger scales.