Wednesday, February 21, 2018

Law Enforcement vs. Security and Privacy

A recent report quoted the Director of the FBI as complaining that he had more than 7000 mobiles for which he has established probable cause to believe contain evidence of a crime, but that their security is so good that he cannot be sure.  Well, perhaps his emphasis was different than mine but you get the gist.

Of course, a decade ago he did not have any.  The modern mobile has given him a rich source of evidence that he has never had before.  Instead of saying ”thank you,” he complains that the source is not even richer than it is.  He neglects to say how many mobiles that he has opened while finding the few that he cannot. He neglects to address what percentage of those contained useful, much less admissable, evidence of crimes, a number that might give us some idea of any probative value of the contents of the 7000.

What he is really complaining about is that the default security of these devices raises his cost of investigation. He does not even speak to the resistance to crimes against the tens of millions of legitimate devices, users applications, data, and information that that security provides. Therefore, he cannot even get to the idea that in the absence of such security, there would be fewer devices, users, and applications, much less that his rich source of evidence might not even exist.

He argues that, in order to reduce his cost, the default security of the devices should be reduced.  In spite of all the testimony against this proposition, and the absence of any in its favor, he argues that the purveyors of the mobiles can reduce his cost while maintaining the security against all others.  Without specifying what would satisfy him, he argues that this is simply a small technical problem that the industry can solve any time it wants to.

While the Director talks in terrms of  ”capability,” that he does not have, I talk in terms of  ”cost.”  I assert that if one has a cryptogram, the method, and the key, all of which are on the mobile device, then, at some price, one can recover the clear text. Depending upon the design of the device, the cost may be high but it is finite.  The Bureau demonstrated this for us in the San Bernardino case. After asserting that Apple could, but that they could not, they turned to the Israelis, who for a  million dollars, recovered the data.  Incidentally it proved to be worth considerably less; it provided neither evidence nor intelligence. On the other hand, on a wholesate basis, the cost per device would be significantly less.

One problem is that, whatever the cost, the Bureau prefers to transfer it to the purveyor and the user than to just pay it. It hopes to do this by sowing enough fear, uncertainty, and doubt that a law and order Congress will pass coercive legislation forcing the uninvolved and unwilling to become arms of law enforcement.  If the purveyor is coerced into reducing the security, i.e., a value, of his product, he will lose sales and profit. Remaining users will lose security and privacy, experience costly breaches, and incur costs for compensating controls. 

The net is that, while the Director may not be able to read every mobile for which he has a warrant, he can read most of them.  While he knows what he cannot read, he bears the burden of proof that reading it would yield evidence or intelligence; he has the data, he must share.  We are not talking about cryptography in general but only about the security of mobile devices.  We are not talking about capabitlity but cost.  Not so much about how much as about who will pay; will we pay by taxation on all or coercion of a few?  The Director may have a case, but he has not made it yet.

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