March 30, 2017

Questions for the FBI on Encryption Mandates

I wrote on Monday about how to analyze a proposal to mandate access to encrypted data. FBI Director James Comey, at the University of Texas last week, talked about encryption policy and his hope that some kind of exceptional access for law enforcement will become available. (Here’s a video.)  Let’s look at what Director Comey said about how a mandate might work.

Here is an extended quote from Director Comey’s answer to an audience question (starting at 51:02 in the video, emphasis added):

The technical thing, look, I really do think we haven’t given this the shot it deserves. President Obama commissioned some work at the end of his Administration because he’d heard a lot from people on device encryption, [that] it’s too hard.  [No], it’s not too hard. It’s not too hard. It requires a change in business model but it is, according to experts inside the U.S. government and a lot of people who will meet with us privately in the private sector, no one actually wants to be seen with us but we meet them out behind the 7/11, they tell us, look, it’s a business model decision.

Take the FBI’s business model. We equip our agents with mobile devices that I think are great mobile devices and we’ve worked hard to make them secure. We have designed it so that we have the ability to access the content. And so I don’t think we have a fatally flawed mobile system in the FBI, and I think nearly every enterprise that is represented here probably has the same. You retain the ability to access the content. So look, one of the worlds I could imagine, I don’t know whether this makes sense, one of the worlds I could imagine is a requirement that if you’re going to sell a device or market a device in the United States, you must be able to comply with judicial process. You figure out how to do it.

And maybe that doesn’t make sense, absent an international component to it, but I just don’t think we, and look, I get it, the makers of devices and the makers of fabulous apps that are riding on top of our devices, on top of our networks, really don’t have an incentive to deal with, to internalize the public safety harm. And I get that. My job is to worry about public safety. Their job is to worry about innovating and selling more units, I totally get that. Somehow we have to bring together, and see if we can’t optimize those two things. And really, given my role, I should not be the one to say, here’s what the technology should look like, nor should they say, no I don’t really care about that public safety aspect.

And what I don’t want to have happen, and I know you agree with me no matter what you think about this, now I think you’re going to agree with what I’m about to say, is we can’t have this conversation after something really bad happens. And look, I don’t want to be a pessimist, but bad things are going to happen. And even I, the Director of the FBI, do not believe that we can have thoughtful conversations about optimizing things we care about in the wake of a serious, serious attack of any kind.

The bolded text is the closest Director Comey came to describing how he imagines a mandate working. He doesn’t suggest that it’s anything like a complete proposal–and anyway that would be too much to ask from an off-the-cuff answer to an audience question. But let’s look at what would be required to turn it into a proposal that can be analyzed. In other words, let’s extrapolate from Director Comey’s answer and try to figure out how he and his team might try to build out a specific proposal based on what he suggested.

The notional mandate would apply at least to retailers (“if you’re going to sell … or market a device”) who sell smartphones to the public “in the United States.” That would include Apple (for sales in Apple Stores), big box retailers like Best Buy, mobile phone carriers’ shops, online retailers like Amazon, and the smaller convenience stores and kiosks that sell cheap smartphones.

Retailers would be required “comply with judicial process.” At a minimum, that would presumably mean that if presented with a smartphone that they had sold, they could extract from it any data encrypted by the user. Which data, and under what circumstances? That would have to be specified, but it’s worth noting that there is a limited amount the retailer can do to control how a user encrypts data on the device. So unless we require retailers to prevent the installation of new software onto the device (and thereby put app stores, and most app sellers, out of business), there would need to be major carve-outs to limit the mandate’s reach to include only cases where the retailer had some control. For example, the mandate might apply only to data encrypted by the software present on the device at the time of sale. That could create an easy loophole for users who wanted to prevent extraction of their encrypted data (by installing encryption software post-sale), but at least it would avoid imposing an impossible requirement on the retailer. (Veterans of the 1990s crypto wars will remember how U.S. software products often shipped without strong crypto, to comply with export controls, but post-sale plug-ins adding crypto were widely available.)

Other classes of devices, such as laptops, tablets, smart devices, and server computers, would either have to be covered, with careful consideration of how they are sold and configured, or they would be excluded, limiting the coverage of the rule. There would need to be rules about devices brought into the United States by their user-owners, or if those devices were not covered, then some law enforcement value would be lost. And the treatment of used devices would have to be specified, including both devices made before the mandate took effect (which would probably need to be exempted, creating another loophole) and post-mandate devices re-sold by a user of merchant: would the original seller or the re-seller be responsible, and what if the reseller is an individual?

Notice that we had to make all of these decisions, and face the attendant unpleasant tradeoffs, before we even reached the question of how to design the technical mechanism to implement key escrow, and how that would affect the security and privacy interests of law-abiding users. The crypto policy discussion often gets hung up on this one issue–the security implications of key escrow–but it is far from the only challenge that needs to be addressed, and the security implications of a key escrow mechanism are far from the only potential drawbacks to be considered.

Director Comey didn’t go to Austin to present an encryption mandate proposal.  But if he or others do decide to push seriously for a mandate, they ought to be able to lay out the details of how they would do it.



How to Analyze An Encryption Access Proposal

It looks like the idea of requiring law enforcement access to encrypted data is back in the news, with the UK government apparently pushing for access in the wake of the recent London attack. With that in mind, let’s talk about how one can go about analyzing a proposed access mandate.

The first thing to recognize is that although law enforcement is often clear about what result they want–getting access to encrypted data–they are often far from clear about how they propose to get that result. There is no magic wand that can give encrypted data to law enforcement and nobody else, while leaving everything else about the world unchanged. If a mandate were to be imposed, this would happen via regulation of companies’ products or behavior.

The operation of a mandate would necessarily be a three stage process: the government imposes specific mandate language, which induces changes in product design and behavior by companies and users, thereby leading to consequences that affect the public good.

Expanding this a bit, we can lay out some questions that a mandate proposal should be prepared to answer:

  1. mandate language: What requirements are imposed, and on whom? Which types of devices and products are covered and which are not? What specifically is required of a device maker? Of an operating system developer? Of a network provider? Of a retailer selling devices? Of an importer of devices? Of a user?
  2. changes in product design and behavior:  How will companies and users react to the mandate? For example, how will companies change the design of their products to comply with the mandate while maintaining their competitive position and serving their customers? How will criminals and terrorists change their behavior? How will law-abiding users adapt? What might foreign governments do to take advantage of these changes?
  3. consequences: What consequences will result from the design and behavioral changes that are predicted? How will the changes affect public safety? Cybersecurity? Personal privacy? The competitiveness of domestic companies? Human rights and free expression?

These questions are important because they expose the kinds of tradeoffs that would have to be made in imposing a mandate. As an example, covering a broad range of devices might allow recovery of more encrypted data (with a warrant), but it might be difficult to write requirements that make sense across a broad spectrum of different device types. As another example, all of the company types that you might regulate come with challenges: some are mostly located outside your national borders, others lack technical sophistication, others touch only a subset of the devices of interest, and so on. Difficult choices abound–and if you haven’t thought about how you would make those choices, then you aren’t in a position to assert that the benefits of a mandate are worth the downsides.

To date, the FBI has not put forward any specific approach. Nor has the UK government, to my knowledge. All they have offered in their public statements are vague assertions that a good approach must exist.

If our law enforcement agencies want to have a grown-up conversation about encryption mandates, they can start by offering a specific proposal, at least for purposes of discussion. Then the serious policy discussion can begin.



How the Politics of Encryption Affects Government Adoption

I wrote yesterday about reports that people in the White House are using encrypted communication apps more often, and why that might be. Today I want to follow up by talking about how the politics of encryption might affect government agencies’ choices about how to secure their information.  I’ll do this by telling the stories of the CIOs of three hypothetical Federal agencies.

Alice is CIO of Agency A. Her agency’s leader has said in speeches that encryption is a tool of criminals and terrorists, and that encryption is used mostly to hide bad or embarrassing acts. Alice knows that if she adopts encryption for the agency, her boss could face criticism for hypocrisy, for using the very technology that he criticizes. Even if there is evidence that encryption will make Agency A more secure, there is a natural tendency for Alice to look for other places to try to improve security instead.

Bob is CIO of Agency B. His agency’s leader has taken a more balanced view, painting encryption as a tool with broad value for honest people, and which happens to be used by bad people as well. Bob will be in a better position than Alice to adopt encryption if he thinks it will improve his agency’s security. But he might hesitate a bit to do so if Agencies A and B need to work together on other issues, or if the two agency heads are friends–especially if encryption seems more important to the head of Agency A than it does to the head of Bob’s own agency.

Charlie is CIO of Agency C. His agency’s leader hasn’t taken a public position on encryption, but the leader is known to be impulsive, thin-skinned, and resistant to advice from domain experts. Charlie worries that if he starts deploying encryption in his agency, and then the leader impulsively takes a strong position against encryption without consulting his team, the resulting accusations of hypocrisy could anger the leader. That might cost Charlie his job, or seriously undermine the authority he needs to properly manage agency IT. The safe thing for Charlie to do is to avoid deploying encryption–not only to preserve his job but also to protect the rest of the agency’s IT agenda. If Charlie doesn’t change the agency’s practice, then criticism of the practice can be deflected onto the previous leader–and of course we’ll be upgrading to the better practice soon. Here the uncertainty created by the leader’s management style deters Charlie from changing encryption practice.

Let’s recap. Alice, Bob, and Charlie are operating in different environments, but in all three cases, the politics of encryption are deterring them, at least a little, from deploying encryption. Their decision to deploy it or not will depend not only on their best judgment as to whether it will improve the agency’s security, but also on political factors that raise the cost of adopting encryption. And so their agencies may not make enough use of encryption.

This is yet another reason we need a serious and specific discussion about encryption policy.