Van's Hardware Journal

Software behemoth Microsoft recently published a paper proposing the tattooing of certain medical patients.  “We propose that access keys be written into patients’ skin using ultraviolet-ink micropigmentation (invisible tattoos),” the abstract reads.

The piece, authored by Microsoft’s Stuart Schechter, maintains that passwords providing wireless access to implanted medical devices like heart pacemakers shouldn’t be entrusted to patents who are unreliable and might be unconscious when device access is needed.

Schechter also shuns medical bracelets claiming they pose privacy risks.  Worse, Schecter believes demented “hackers” exist who might read bracelets’ passwords to hack into implanted devices for nefarious and perhaps even homicidal purposes.  However, easily constructed electromagnetic pulse devices could obtain the same deadly results without requiring security code knowledge.

We propose that a user-selected human-readable key be encoded directly onto patients using ultraviolet-ink micropigmentation, adjacent to the point of implantation. To increase reliability the encoding could be augmented
to include an error correcting code and/or be replicated in full on the base of the patient’s leftmost foot—at the
arch. All devices used to communicate with the IMD would be equipped with a small, reliable, and inexpensive
ultraviolet light emitting diode (UV LED) and an input mechanism for key entry (a keypad or touch-screen).
A single key would be sufficient for multiple devices and could be re-used when devices are replaced.

The key encodings could take the form of user chosen character strings (optimizing for user choice), random
character strings (optimizing for minimal size), or strings of hieroglyphic-like images chosen from a subset
deemed acceptable to the user. The first option gives the greatest control to reluctant patients, whereas latter
two options guarantee a minimum level of key entropy and can easily be augmented with error correcting codes.
Each patient would be allowed to request new random encodings until finding one he or she deemed acceptable.

Schechter recognizes the obvious parallels with Nazi Germany prison camps.

In the holocaust, identification tattoos reminded prisoners [they] no longer controlled their own bodies. Giving the patient a choice of whether or not to use micropigmentation, the type of encoding to use, and some control over the process that generates the encoding should help to address these concerns.