This is scary. I would hope that as caselaw becomes more extensive and complete they split this into two parts. I have no qualms about allowing police to compel finger prints of any degree of fidelity. It is already standard practice to photograph and finger print every arrested person, so this is little change from decades worth of standard practice. However, I think they should split this when it comes to the step of fabricating a fake finger (or compelling the defendant to use their own finger) to unlock any secure data store (phone, computer, network file server(that is a scary hole in the security system itself!), safe, etc. If they have gone to the effort of securing access with a finger print then the information inside is clealry not 'public domain'. It should be as secure as their own testimony. It should be illegal for them to 'force' entry with a fake finger, and they should not be able to use any data inside, nor any further leads developed from data learned by that process. However, I am not confident that the world will be that reasonable.

A second weakness in my argument is that on TV, they routinely hack into someone's encrypted files and disks. If they can actually use anything that they can hack out of your computer, then faking a finger print to gain access is just a partially physical method of doing the same encryption hacking.

If this turns out to be the case, or becomes the case, then there would be no safe way to store any information digitally. And since having a passphrase to unlock a large encryption key is no more secure than the passphrase and encryption key storage program, I begin to wonder about encrypting entire disks with a 2048 bit key that IS the passphrase! Now we just need to learn how to do passphrases with 2048 bits of significant data. ugh! Upper and lowercase letters, digits, punctuation only give about 6 1/2 bits per character. That would need a 315 character pass phrase to remember and type in each time to get maximum security. And don't even think about writing it down somewhere! :)

Mike
 
The Smartphone versus the Fifth Amendment," Berkeley Technology Law Journal, 21 Dec 2014[3]
in the aftermath of Virginia v. Baust, many smartphone users may soon reconsider their reliance on fingerprint ID technology.

In October [2014], a Virginia trial judge ruled [in Virginia v. Baust] that unlike a passcode, the production of one's fingerprint is not "testimonial communication", and therefore, the Fifth Amendment privilege against self-incrimination cannot be invoked. Rather, the government may properly compel the production of a smartphone user's fingerprint to unlock the user's device. This force compulsion would ostensibly extend to any applications within a device that can be opened via fingerprint.

However,

As a trial court, the ruling in Virginia v. Baust is not mandatory law. However, as with any early caselaw in a novel and undeveloped area of the law, this opinion will likely be cited as a persuasive authority.

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"Creativity is intelligence having fun." — Albert Einstein