Thursday, September 19, 2013, by Christian Landreth
Excitement surrounding the September 20, 2013 release of the iPhone 5s has been somewhat tempered by privacy concerns related to Apple’s new Touch ID technology. Touch ID is a security feature that “uses a laser cut sapphire crystal, together with the capacitive touch sensor, to take a high-resolution image of your fingerprint,” allowing users to unlock their phones without entering a password. Images of fingerprints would remain stored in a chip within the iPhone.
Perhaps as a result of the NSA Surveillance Scandal, Americans seem to be especially worried about intrusions into their private lives. With a quarter of American cell phone users now owning an iPhone, Apple’s announcement was bound to spark controversy.
The NSA has already proved that it is able to hack into and collect information from almost any encrypted database, from medical records to banking systems. Opponents the NSA’s practices are wondering what, if anything, would prevent the agency from stealing fingerprints off of smartphones in the name of preventing terrorism. They argue that if such a practice were permitted, then a database full of fingerprints would become available to not only the NSA, but also a number of other federal law enforcement agencies.
Your prints could be used to unlock and reveal the contents of your phone, despite your objections, because prints are biometrics and would not require you to “reveal the contents of your mind.”
Others argue that such concerns are overblown because Touch ID uses a biometric template that lists features and positions on the fingerprint (rather than a full image) to verify the user, and thus would not be useful to law enforcement seeking to match prints to a crime scene.
Aside from the concern that the NSA may one day use Touch ID to create a nationwide fingerprint database, there looms a potentially greater risk that Touch ID may infringe upon citizens’ Fifth Amendment rights. The Fifth Amendment contains the privilege against self-incrimination, but for the privilege to apply, the government must try to compel an incriminating “testimonial” statement. The privilege is sacred in that not even a judge can force someone to testify in a way that would be incriminating. However, biometrics (such as DNA or fingerprints) are not protected under the privilege.
Testimonial statements “reveal the contents of your mind”. The Supreme Court of the United States has used an example that explains the difference between testimonial communication and biometrics. Being forced to turn over the key to a lockbox containing incriminating documents is not testimonial in that you did not have to reveal anything you know – you could physically hand over the key without saying anything. However, being asked to tell police the combination to a safe is testimonial, and thus protected under the Fifth Amendment.
This distinction has implications for iPhone 5s users in that a fingerprint could be likened to the lockbox key. Your prints could be used to unlock and reveal the contents of your phone, despite your objections, because prints are biometrics and would not require you to “reveal the contents of your mind.” Previous editions of the iPhone use PIN numbers as the unlocking mechanism. This method would be entitled to Fifth Amendment protection because it would be necessary for you to provide testimony against yourself to unlock the phone by revealing a PIN you had memorized – similar to the safe combination in the Supreme Court’s example.
For all the discussion of the grave implications of Touch ID, this seems to be a problem with a relatively simple solution, which Apple could likely implement easily. As Marcia Hoffman has suggested, giving users the option to unlock their phones with a fingerprint scan plus something else (such as a pin) would prevent fingerprints from unintentionally becoming the “key to the lockbox.”
Another option would be to let the user choose either to use their fingerprint as the unlocking mechanism or to have a pin. This would allow the user to avoid the hassle of using two authentication procedures, yet still having the ability to avail themselves to the protection of the Fifth Amendment, all while preventing the NSA from hacking their phone and stealing collecting their fingerprints.