Abstract: Payment card fraud results in billions of dollars in losses annually. Adversaries increasingly acquire card data using skimmers, which are attached to legitimate payment devices including point of sale terminals, gas pumps, and ATMs. Detecting such devices can be difficult, and while many experts offer advice in doing so, there exists no large-scale characterization of skimmer technology to support such defenses. In this paper, we perform the first such study based on skimmers recovered by the NYPD's Financial Crimes Task Force over a 16 month period. After systematizing these devices, we develop the Skim Reaper, a detector which takes advantage of the physical properties and constraints necessary for many skimmers to steal card data. Our analysis shows the Skim Reaper effectively detects 100% of devices supplied by the NYPD. In so doing, we provide the first robust and portable mechanism for detecting card skimmers.
Earlier this month, I wrote about a statement by the Five Eyes countries about encryption and back doors. (Short summary: they like them.) One of the weird things about the statement is that it was clearly written from a law-enforcement perspective, though we normally think of the Five Eyes as a consortium of intelligence agencies.
Susan Landau examines the details of the statement, explains what's going on, and why the statement is a lot less than what it might seem.
Some of us -- myself included -- have proposed lawful government hacking as an alternative to backdoors. A new report from the Center of Internet and Society looks at the security risks of allowing government hacking. They include:
Disincentive for vulnerability disclosure
Cultivation of a market for surveillance tools
Attackers co-opt hacking tools over which governments have lost control
Attackers learn of vulnerabilities through government use of malware
Government incentives to push for less-secure software and standards
Government malware affects innocent users.
These risks are real, but I think they're much less than mandating backdoors for everyone. From the report's conclusion:
Government hacking is often lauded as a solution to the "going dark" problem. It is too dangerous to mandate encryption backdoors, but targeted hacking of endpoints could ensure investigators access to same or similar necessary data with less risk. Vulnerabilities will never affect everyone, contingent as they are on software, network configuration, and patch management. Backdoors, however, mean everybody is vulnerable and a security failure fails catastrophically. In addition, backdoors are often secret, while eventually, vulnerabilities will typically be disclosed and patched.
The key to minimizing the risks is to ensure that law enforcement (or whoever) report all vulnerabilities discovered through the normal process, and use them for lawful hacking during the period between reporting and patching. Yes, that's a big ask, but the alternatives are worse.
According to a new CSIS report, "going dark" is not the most pressing problem facing law enforcement in the age of digital data:
Over the past year, we conducted a series of interviews with federal, state, and local law enforcement officials, attorneys, service providers, and civil society groups. We also commissioned a survey of law enforcement officers from across the country to better understand the full range of difficulties they are facing in accessing and using digital evidence in their cases. Survey results indicate that accessing data from service providers -- much of which is not encrypted -- is the biggest problem that law enforcement currently faces in leveraging digital evidence.
This is a problem that has not received adequate attention or resources to date. An array of federal and state training centers, crime labs, and other efforts have arisen to help fill the gaps, but they are able to fill only a fraction of the need. And there is no central entity responsible for monitoring these efforts, taking stock of the demand, and providing the assistance needed. The key federal entity with an explicit mission to assist state and local law enforcement with their digital evidence needs -- the National Domestic Communications Assistance Center (NDCAC)has a budget of $11.4 million, spread among several different programs designed to distribute knowledge about service providers' policies and products, develop and share technical tools, and train law enforcement on new services and technologies, among other initiatives.
In addition to bemoaning the lack of guidance and help from tech companies -- a quarter of survey respondents said their top issue was convincing companies to hand over suspects' data -- law enforcement officials also reported receiving barely any digital evidence training. Local police said they'd received only 10 hours of training in the past 12 months; state police received 13 and federal officials received 16. A plurality of respondents said they only received annual training. Only 16 percent said their organizations scheduled training sessions at least twice per year.
This is a point that Susan Landau has repeatedly made, and also one I make in my new book. The FBI needs technical expertise, not backdoors.
The New York Times is reporting about a company called Securus Technologies that gives police the ability to track cell phone locations without a warrant:
The service can find the whereabouts of almost any cellphone in the country within seconds. It does this by going through a system typically used by marketers and other companies to get location data from major cellphone carriers, including AT&T, Sprint, T-Mobile and Verizon, documents show.
Last month, Wired published a long article about Ray Ozzie and his supposed new scheme for adding a backdoor in encrypted devices. It's a weird article. It paints Ozzie's proposal as something that "attains the impossible" and "satisfies both law enforcement and privacy purists," when (1) it's barely a proposal, and (2) it's essentially the same key escrow scheme we've been hearing about for decades.
Basically, each device has a unique public/private key pair and a secure processor. The public key goes into the processor and the device, and is used to encrypt whatever user key encrypts the data. The private key is stored in a secure database, available to law enforcement on demand. The only other trick is that for law enforcement to use that key, they have to put the device in some sort of irreversible recovery mode, which means it can never be used again. That's basically it.
I have no idea why anyone is talking as if this were anything new. Severalcryptographershavealreadyexplained why this key escrow scheme is no better than any other key escrow scheme. The short answer is (1) we won't be able to secure that database of backdoor keys, (2) we don't know how to build the secure coprocessor the scheme requires, and (3) it solves none of the policy problems around the whole system. This is the typical mistake non-cryptographers make when they approach this problem: they think that the hard part is the cryptography to create the backdoor. That's actually the easy part. The hard part is ensuring that it's only used by the good guys, and there's nothing in Ozzie's proposal that addresses any of that.
I worry that this kind of thing is damaging in the long run. There should be some rule that any backdoor or key escrow proposal be a fully specified proposal, not just some cryptography and hand-waving notions about how it will be used in practice. And before it is analyzed and debated, it should have to satisfy some sort of basic security analysis. Otherwise, we'll be swatting pseudo-proposals like this one, while those on the other side of this debate become increasingly convinced that it's possible to design one of these things securely.
Already people are using the National Academies report on backdoors for law enforcement as evidence that engineers are developing workable and secure backdoors. Writing in Lawfare, Alan Z. Rozenshtein claims that the report -- and a related New York Timesstory -- "undermine the argument that secure third-party access systems are so implausible that it's not even worth trying to develop them." Susan Landau effectively corrects this misconception, but the damage is done.
Here's the thing: it's not hard to design and build a backdoor. What's hard is building the systems -- both technical and procedural -- around them. Here's Rob Graham:
He's only solving the part we already know how to solve. He's deliberately ignoring the stuff we don't know how to solve. We know how to make backdoors, we just don't know how to secure them.
A bunch of us cryptographers have already explained why we don't think this sort of thing will work in the foreseeable future. We write:
Exceptional access would force Internet system developers to reverse "forward secrecy" design practices that seek to minimize the impact on user privacy when systems are breached. The complexity of today's Internet environment, with millions of apps and globally connected services, means that new law enforcement requirements are likely to introduce unanticipated, hard to detect security flaws. Beyond these and other technical vulnerabilities, the prospect of globally deployed exceptional access systems raises difficult problems about how such an environment would be governed and how to ensure that such systems would respect human rights and the rule of law.
The reason so few of us are willing to bet on massive-scale key escrow systems is that we've thought about it and we don't think it will work. We've looked at the threat model, the usage model, and the quality of hardware and software that exists today. Our informed opinion is that there's no detection system for key theft, there's no renewability system, HSMs are terrifically vulnerable (and the companies largely staffed with ex-intelligence employees), and insiders can be suborned. We're not going to put the data of a few billion people on the line an environment where we believe with high probability that the system will fail.
Some details about the iPhone unlocker from the US company Greyshift, with photos.
Little is known about Grayshift or its sales model at this point. We don't know whether sales are limited to US law enforcement, or if it is also selling in other parts of the world. Regardless of that, it's highly likely that these devices will ultimately end up in the hands of agents of an oppressive regime, whether directly from Grayshift or indirectly through the black market.
It's also entirely possible, based on the history of the IP-Box, that Grayshift devices will end up being available to anyone who wants them and can find a way to purchase them, perhaps by being reverse-engineered and reproduced by an enterprising hacker, then sold for a couple hundred bucks on eBay.
For over a decade, civil libertarians have been fighting government mass surveillance of innocent Americans over the Internet. We've just lost an important battle. On January 18, President Trumpsigned the renewal of Section 702, domestic mass surveillance became effectively a permanent part of US law.
Section 702 was initially passed in 2008, as an amendment to the Foreign Intelligence Surveillance Act of 1978. As the title of that law says, it was billed as a way for the NSA to spy on non-Americans located outside the United States. It was supposed to be an efficiency and cost-saving measure: the NSA was already permitted to tap communications cables located outside the country, and it was already permitted to tap communications cables from one foreign country to another that passed through the United States. Section 702 allowed it to tap those cables from inside the United States, where it was easier. It also allowed the NSA to request surveillance data directly from Internet companies under a program called PRISM.
The problem is that this authority also gave the NSA the ability to collect foreign communications and data in a way that inherently and intentionally also swept up Americans' communications as well, without a warrant. Other law enforcement agencies are allowed to ask the NSA to search those communications, give their contents to the FBI and other agencies and then lie about their origins in court.
In 1978, after Watergate had revealed the Nixon administration's abuses of power, we erected a wall between intelligence and law enforcement that prevented precisely this kind of sharing of surveillance data under any authority less restrictive than the Fourth Amendment. Weakening that wall is incredibly dangerous, and the NSA should never have been given this authority in the first place.
Arguably, it never was. The NSA had been doing this type of surveillance illegally for years, something that was first made public in 2006. Section 702 was secretly used as a way to paper over that illegal collection, but nothing in the text of the later amendment gives the NSA this authority. We didn't know that the NSA was using this law as the statutory basis for this surveillance until Edward Snowden showed us in 2013.
Civil libertarians have been battling this law in both Congress and the courts ever since it was proposed, and the NSA's domestic surveillance activities even longer. What this most recent vote tells me is that we've lost that fight.
Section 702 was passed under George W. Bush in 2008, reauthorized under Barack Obama in 2012, and now reauthorized again under Trump. In all three cases, congressional support was bipartisan. It has survived multiple lawsuits by the Electronic Frontier Foundation, the ACLU, and others. It has survived the revelations by Snowden that it was being used far more extensively than Congress or the public believed, and numerous public reports of violations of the law. It has even survived Trump's belief that he was being personally spied on by the intelligence community, as well as any congressional fears that Trump could abuse the authority in the coming years. And though this extension lasts only six years, it's inconceivable to me that it will ever be repealed at this point.
So what do we do? If we can't fight this particular statutory authority, where's the new front on surveillance? There are, it turns out, reasonable modifications that target surveillance more generally, and not in terms of any particular statutory authority. We need to look at US surveillance law more generally.
First, we need to strengthen the minimization procedures to limit incidental collection. Since the Internet was developed, all the world's communications travel around in a single global network. It's impossible to collect only foreign communications, because they're invariably mixed in with domestic communications. This is called "incidental" collection, but that's a misleading name. It's collected knowingly, and searched regularly. The intelligence community needs much stronger restrictions on which American communications channels it can access without a court order, and rules that require they delete the data if they inadvertently collect it. More importantly, "collection" is defined as the point the NSA takes a copy of the communications, and not later when they search their databases.
Second, we need to limit how other law enforcement agencies can use incidentally collected information. Today, those agencies can query a database of incidental collection on Americans. The NSA can legally pass information to those other agencies. This has to stop. Data collected by the NSA under its foreign surveillance authority should not be used as a vehicle for domestic surveillance.
The most recent reauthorization modified this lightly, forcing the FBI to obtain a court order when querying the 702 data for a criminal investigation. There are still exceptions and loopholes, though.
Third, we need to end what's called "parallel construction." Today, when a law enforcement agency uses evidence found in this NSA database to arrest someone, it doesn't have to disclose that fact in court. It can reconstruct the evidence in some other manner once it knows about it, and then pretend it learned of it that way. This right to lie to the judge and the defense is corrosive to liberty, and it must end.
Pressure to reform the NSA will probably first come from Europe. Already, European Union courts have pointed to warrantless NSA surveillance as a reason to keep Europeans' data out of US hands. Right now, there is a fragile agreement between the EU and the United States -- called "Privacy Shield" -- that requires Americans to maintain certain safeguards for international data flows. NSA surveillance goes against that, and it's only a matter of time before EU courts start ruling this way. That'll have significant effects on both government and corporate surveillance of Europeans and, by extension, the entire world.
Further pressure will come from the increased surveillance coming from the Internet of Things. When your home, car, and body are awash in sensors, privacy from both governments and corporations will become increasingly important. Sooner or later, society will reach a tipping point where it's all too much. When that happens, we're going to see significant pushback against surveillance of all kinds. That's when we'll get new laws that revise all government authorities in this area: a clean sweep for a new world, one with new norms and new fears.
It's possible that a federal court will rule on Section 702. Although there have been many lawsuits challenging the legality of what the NSA is doing and the constitutionality of the 702 program, no court has ever ruled on those questions. The Bush and Obama administrations successfully argued that defendants don't have legal standing to sue. That is, they have no right to sue because they don't know they're being targeted. If any of the lawsuits can get past that, things might change dramatically.
Meanwhile, much of this is the responsibility of the tech sector. This problem exists primarily because Internet companies collect and retain so much personal data and allow it to be sent across the network with minimal security. Since the government has abdicated its responsibility to protect our privacy and security, these companies need to step up: Minimize data collection. Don't save data longer than absolutely necessary. Encrypt what has to be saved. Well-designed Internet services will safeguard users, regardless of government surveillance authority.
For the rest of us concerned about this, it's important not to give up hope. Everything we do to keep the issue in the public eye -- and not just when the authority comes up for reauthorization again in 2024 -- hastens the day when we will reaffirm our rights to privacy in the digital age.