(and not the pacman kind…) Ghosts in the Machine (and not the pacman kind…)

The Computer Knows More…

The Modern Equivalent?

Digital Information is Not Analog Information When things are converted to digital, they are converted to bits and bits behave differently than real-world things Take the redacted text Highlighting the text does not remove it It makes it harder to see visually, just like in the olden days But unlike the olden days, digital highlighting is easy to remove and the text is still there, perfectly…

Switching to Digital – What is Gained? It is easier to search digital information It is easier to store digital information It is easier to send digital information

Switching to Digital – What is Lost? Bits cannot perfectly encode real-world information For example, if you record a symphony, small nuances of the music are lost

Data Leaks The pervasive storage of data means that it can be easily stolen It also means that features we use can haunt us Criminals can be convicted based on texts or instant messages they send Leaving Microsoft Word’s Track Changes features on can completely shatter your hopes of suing someone Sensitive data about your CIA agents (like their name) can be extracted because you just highlighted over them rather than erasing the name

Bit Models Bits model reality enough to fool the eye… But if you were to take apart the hard drive and peel away the abstractions, the bits do not resemble what they represent Analog is a better representation of reality In the old days, voices were carried over telephone wires and the electricity on the wire accurately represented the voice inflection of the speaker Now, its just bits, we can send voice information faster, but its not entirely accurate

Metadata Files often include metadata which is just information about the file itself like How big it is When it was created When it was last modified Which part of the file contains which piece of information

Just Binary But Many Things The same string of 8 bits can be many things: Text Audio Images Formatting Information in Word One way that computers (at least windows computers) know what the bits are is through file extensions This method has the drawback of the document becoming nonsense if you change the extension

Changing Reality Bits can be easily altered Time and date stamps can be changed, authorship information can be modified Photos can be changed or created from nothing Evidence can be forged Child pornography can be created There are methods that can be used to establish that a photo has not been changed, but they are subject to the limitations of all other digital things

Pictures = Pixels So what are digital pictures really… Remember RGB? Each picture is divided up into tiny, tiny squares known as a pixel and each pixel has a RGB value When you take a picture with you camera, the camera has thousands of tiny receptors that interpret the light hitting your camera That receptor converts the light into an RGB value and a pixel is born Note: the receptors in modern cameras sometimes generate more than one pixel per receptor