Entries Tagged "key escrow"

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G7 Comes Out in Favor of Encryption Backdoors

From a G7 meeting of interior ministers in Paris this month, an “outcome document“:

Encourage Internet companies to establish lawful access solutions for their products and services, including data that is encrypted, for law enforcement and competent authorities to access digital evidence, when it is removed or hosted on IT servers located abroad or encrypted, without imposing any particular technology and while ensuring that assistance requested from internet companies is underpinned by the rule law and due process protection. Some G7 countries highlight the importance of not prohibiting, limiting, or weakening encryption;

There is a weird belief amongst policy makers that hacking an encryption system’s key management system is fundamentally different than hacking the system’s encryption algorithm. The difference is only technical; the effect is the same. Both are ways of weakening encryption.

Posted on April 23, 2019 at 9:14 AMView Comments

IEEE Statement on Strong Encryption vs. Backdoors

The IEEE came out in favor of strong encryption:

IEEE supports the use of unfettered strong encryption to protect confidentiality and integrity of data and communications. We oppose efforts by governments to restrict the use of strong encryption and/or to mandate exceptional access mechanisms such as “backdoors” or “key escrow schemes” in order to facilitate government access to encrypted data. Governments have legitimate law enforcement and national security interests. IEEE believes that mandating the intentional creation of backdoors or escrow schemes — no matter how well intentioned — does not serve those interests well and will lead to the creation of vulnerabilities that would result in unforeseen effects as well as some predictable negative consequences

The full statement is here.

Posted on June 27, 2018 at 6:44 AMView Comments

Ray Ozzie's Encryption Backdoor

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. Several cryptographers have already explained 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 Times story — “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.

Finally, Matthew Green:

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.

EDITED TO ADD (5/14): An analysis of the proposal.

Posted on May 7, 2018 at 9:32 AMView Comments

More on the Going Dark Debate

Lawfare is turning out to be the go-to blog for policy wonks about various government debates on cybersecurity. There are two good posts this week on the Going Dark debate.

The first is from those of us who wrote the “Keys Under Doormats” paper last year, criticizing the concept of backdoors and key escrow. We were responding to a half-baked proposal on how to give the government access without causing widespread insecurity, and we pointed out where almost of all of these sorts of proposals fall short:

1. Watch for systems that rely on a single powerful key or a small set of them.

2. Watch for systems using high-value keys over and over and still claiming not to increase risk.

3. Watch for the claim that the abstract algorithm alone is the measure of system security.

4. Watch for the assumption that scaling anything on the global Internet is easy.

5. Watch for the assumption that national borders are not a factor.

6. Watch for the assumption that human rights and the rule of law prevail throughout the world.

The second is by Susan Landau, and is a response to the ODNI’s response to the “Don’t Panic” report. Our original report said basically that the FBI wasn’t going dark and that surveillance information is everywhere. At a Senate hearing, Sen. Wyden requested that the Office of the Director of National Intelligence respond to the report. It did — not very well, honestly — and Landau responded to that response. She pointed out that there really wasn’t much disagreement: that the points it claimed to have issue with were actually points we made and agreed with.

In the end, the ODNI’s response to our report leaves me somewhat confused. The reality is that the only strong disagreement seems to be with an exaggerated view of one finding. It almost appears as if ODNI is using the Harvard report as an opportunity to say, “Widespread use of encryption will make our work life more difficult.” Of course it will. Widespread use of encryption will also help prevent some of the cybersecurity exploits and attacks we have been experiencing over the last decade. The ODNI letter ignored that issue.

EDITED TO ADD: Related is this article where James Comey defends spending $1M+ on that iPhone vulnerability. There’s some good discussion of the vulnerabilities equities process, and the FBI’s technical lack of sophistication.

Posted on May 13, 2016 at 6:55 AMView Comments

Companies Handing Source Code Over to Governments

ZDNet has an article on US government pressure on software companies to hand over copies of their source code. There’s no details because no one is talking on the record, but I also believe that this is happening.

When asked, a spokesperson for the Justice Dept. acknowledged that the department has demanded source code and private encryption keys before.

These orders would probably come from the FISA Court:

These orders are so highly classified that simply acknowledging an order’s existence is illegal, even a company’s chief executive or members of the board may not be told. Only those who are necessary to execute the order would know, and would be subject to the same secrecy provisions.

Given that Federighi heads the division, it would be almost impossible to keep from him the existence of a FISA order demanding the company’s source code.

It would not be the first time that the US government has reportedly used proprietary code and technology from American companies to further its surveillance efforts.

Top secret NSA documents leaked by whistleblower Edward Snowden, reported in German magazine Der Spiegel in late-2013, have suggested some hardware and software makers were compelled to hand over source code to assist in government surveillance.

The NSA’s catalog of implants and software backdoors suggest that some companies, including Dell, Huawei, and Juniper — which was publicly linked to an “unauthorized” backdoor — had their servers and firewall products targeted and attacked through various exploits. Other exploits were able to infiltrate firmware of hard drives manufactured by Western Digital, Seagate, Maxtor, and Samsung.

Last year, antivirus maker and security firm Kaspersky later found evidence that the NSA had obtained source code from a number of prominent hard drive makers — a claim the NSA denied — to quietly install software used to eavesdrop on the majority of the world’s computers.

“There is zero chance that someone could rewrite the [hard drive] operating system using public information,” said one of the researchers.

The problem is, of course, is that any company forced by the US to hand over their source code would also be forbidden from talking about it.

It’s the sort of thing China does:

For most computing and networking equipment, the chart says, source code must be turned over to Chinese officials. But many foreign companies would be unwilling to disclose code because of concerns about intellectual property, security and, in some cases, United States export law.

The chart also calls for companies that want to sell to banks to set up research and development centers in China, obtain permits for workers servicing technology equipment and build “ports” to allow Chinese officials to manage and monitor data processed by their hardware.

The draft antiterrorism law pushes even further, calling for companies to store all data related to Chinese users on servers in China, create methods for monitoring content for terror threats and provide keys to encryption to public security authorities.

Slashdot thread.

Posted on March 18, 2016 at 11:27 AMView Comments

New NIST Encryption Guidelines

NIST has published a draft of their new standard for encryption use: “NIST Special Publication 800-175B, Guideline for Using Cryptographic Standards in the Federal Government: Cryptographic Mechanisms.” In it, the Escrowed Encryption Standard from the 1990s, FIPS-185, is no longer certified. And Skipjack, NSA’s symmetric algorithm from the same period, will no longer be certified.

I see nothing sinister about decertifying Skipjack. In a world of faster computers and post-quantum thinking, an 80-bit key and 64-bit block no longer cut it.

ETA: My essays from 1998 on Skipjack and KEA.

Posted on March 17, 2016 at 9:54 AMView Comments

Judge Demands that Apple Backdoor an iPhone

A judge has ordered that Apple bypass iPhone security in order for the FBI to attempt a brute-force password attack on an iPhone 5c used by one of the San Bernardino killers. Apple is refusing.

The order is pretty specific technically. This implies to me that what the FBI is asking for is technically possible, and even that Apple assisted in the wording so that the case could be about the legal issues and not the technical ones.

From Apple’s statement about its refusal:

Some would argue that building a backdoor for just one iPhone is a simple, clean-cut solution. But it ignores both the basics of digital security and the significance of what the government is demanding in this case.

In today’s digital world, the “key” to an encrypted system is a piece of information that unlocks the data, and it is only as secure as the protections around it. Once the information is known, or a way to bypass the code is revealed, the encryption can be defeated by anyone with that knowledge.

The government suggests this tool could only be used once, on one phone. But that’s simply not true. Once created, the technique could be used over and over again, on any number of devices. In the physical world, it would be the equivalent of a master key, capable of opening hundreds of millions of locks ­ from restaurants and banks to stores and homes. No reasonable person would find that acceptable.

The government is asking Apple to hack our own users and undermine decades of security advancements that protect our customers ­ including tens of millions of American citizens ­ from sophisticated hackers and cybercriminals. The same engineers who built strong encryption into the iPhone to protect our users would, ironically, be ordered to weaken those protections and make our users less safe.

We can find no precedent for an American company being forced to expose its customers to a greater risk of attack. For years, cryptologists and national security experts have been warning against weakening encryption. Doing so would hurt only the well-meaning and law-abiding citizens who rely on companies like Apple to protect their data. Criminals and bad actors will still encrypt, using tools that are readily available to them.

Congressman Ted Lieu comments.

Here’s an interesting essay about why Tim Cook and Apple are such champions for encryption and privacy.

Today I walked by a television showing CNN. The sound was off, but I saw an aerial scene which I presume was from San Bernardino, and the words “Apple privacy vs. national security.” If that’s the framing, we lose. I would have preferred to see “National security vs. FBI access.”

Slashdot thread.

EDITED TO ADD (2/18): Good analysis of Apple’s case. Interesting debate. Nicholas Weaver’s comments. And commentary from some other planet.

EDITED TO ADD (2/19): Ben Adida comments:

What’s probably happening is that the FBI is using this as a test case for the general principle that they should be able to compel tech companies to assist in police investigations. And that’s pretty smart, because it’s a pretty good test case: Apple obviously wants to help prevent terrorist attacks, so they’re left to argue the slippery slope argument in the face of an FBI investigation of a known terrorist. Well done, FBI, well done.

And Julian Sanchez’s comments. His conclusion:

These, then, are the high stakes of Apple’s resistance to the FBI’s order: not whether the federal government can read one dead terrorism suspect’s phone, but whether technology companies can be conscripted to undermine global trust in our computing devices. That’s a staggeringly high price to pay for any investigation.

A New York Times editorial.

Also, two questions: One, what do we know about Apple’s assistance in the past, and why this one is different? Two, has anyone speculated on how much this will cost Apple? The FBI is demanding that Apple give them free engineering work. What’s the value of that work?

EDITED TO ADD (2/20): Jonathan Zdziarski writes on the differences between the FBI compelling someone to provide a service versus build a tool, and why the latter will 1) be difficult and expensive, 2) will get out into the wild, and 3) set a dangerous precedent.

This answers my first question, above:

For years, the government could come to Apple with a subpoena and a phone, and have the manufacturer provide a disk image of the device. This largely worked because Apple didn’t have to hack into their phones to do this. Up until iOS 8, the encryption Apple chose to use in their design was easily reversible when you had code execution on the phone (which Apple does). So all through iOS 7, Apple only needed to insert the key into the safe and provide FBI with a copy of the data.

EFF wrote a good technical explainer on the case. My only complaint is with the last section. I have heard directly from Apple that this technique still works on current model phones using the current iOS version.

I am still stunned by how good a case the FBI chose to push this. They have all the sympathy in the media that they could hope for.

EDITED TO ADD (2/20): Tim Cook as privacy advocate. How the back door works on modern iPhones. Why the average American should care. The grugq on what this all means.

EDITED TO ADD (2/22): I wrote an op ed for the Washington Post.

Posted on February 17, 2016 at 2:15 PMView Comments

Security vs. Surveillance

Both the “going dark” metaphor of FBI Director James Comey and the contrasting “golden age of surveillance” metaphor of privacy law professor Peter Swire focus on the value of data to law enforcement. As framed in the media, encryption debates are about whether law enforcement should have surreptitious access to data, or whether companies should be allowed to provide strong encryption to their customers.

It’s a myopic framing that focuses only on one threat — criminals, including domestic terrorists — and the demands of law enforcement and national intelligence. This obscures the most important aspects of the encryption issue: the security it provides against a much wider variety of threats.

Encryption secures our data and communications against eavesdroppers like criminals, foreign governments, and terrorists. We use it every day to hide our cell phone conversations from eavesdroppers, and to hide our Internet purchasing from credit card thieves. Dissidents in China and many other countries use it to avoid arrest. It’s a vital tool for journalists to communicate with their sources, for NGOs to protect their work in repressive countries, and for attorneys to communicate with their clients.

Many technological security failures of today can be traced to failures of encryption. In 2014 and 2015, unnamed hackers — probably the Chinese government — stole 21.5 million personal files of U.S. government employees and others. They wouldn’t have obtained this data if it had been encrypted. Many large-scale criminal data thefts were made either easier or more damaging because data wasn’t encrypted: Target, TJ Maxx, Heartland Payment Systems, and so on. Many countries are eavesdropping on the unencrypted communications of their own citizens, looking for dissidents and other voices they want to silence.

Adding backdoors will only exacerbate the risks. As technologists, we can’t build an access system that only works for people of a certain citizenship, or with a particular morality, or only in the presence of a specified legal document. If the FBI can eavesdrop on your text messages or get at your computer’s hard drive, so can other governments. So can criminals. So can terrorists. This is not theoretical; again and again, backdoor accesses built for one purpose have been surreptitiously used for another. Vodafone built backdoor access into Greece’s cell phone network for the Greek government; it was used against the Greek government in 2004-2005. Google kept a database of backdoor accesses provided to the U.S. government under CALEA; the Chinese breached that database in 2009.

We’re not being asked to choose between security and privacy. We’re being asked to choose between less security and more security.

This trade-off isn’t new. In the mid-1990s, cryptographers argued that escrowing encryption keys with central authorities would weaken security. In 2013, cybersecurity researcher Susan Landau published her excellent book Surveillance or Security?, which deftly parsed the details of this trade-off and concluded that security is far more important.

Ubiquitous encryption protects us much more from bulk surveillance than from targeted surveillance. For a variety of technical reasons, computer security is extraordinarily weak. If a sufficiently skilled, funded, and motivated attacker wants in to your computer, they’re in. If they’re not, it’s because you’re not high enough on their priority list to bother with. Widespread encryption forces the listener — whether a foreign government, criminal, or terrorist — to target. And this hurts repressive governments much more than it hurts terrorists and criminals.

Of course, criminals and terrorists have used, are using, and will use encryption to hide their planning from the authorities, just as they will use many aspects of society’s capabilities and infrastructure: cars, restaurants, telecommunications. In general, we recognize that such things can be used by both honest and dishonest people. Society thrives nonetheless because the honest so outnumber the dishonest. Compare this with the tactic of secretly poisoning all the food at a restaurant. Yes, we might get lucky and poison a terrorist before he strikes, but we’ll harm all the innocent customers in the process. Weakening encryption for everyone is harmful in exactly the same way.

This essay previously appeared as part of the paper “Don’t Panic: Making Progress on the ‘Going Dark’ Debate.” It was reprinted on Lawfare. A modified version was reprinted by the MIT Technology Review.

Posted on February 3, 2016 at 6:09 AMView Comments

UK Government Promoting Backdoor-Enabled Voice Encryption Protocol

The UK government is pushing something called the MIKEY-SAKKE protocol to secure voice. Basically, it’s an identity-based system that necessarily requires a trusted key-distribution center. So key escrow is inherently built in, and there’s no perfect forward secrecy. The only reasonable explanation for designing a protocol with these properties is third-party eavesdropping.

Steven Murdoch has explained the details. The upshot:

The design of MIKEY-SAKKE is motivated by the desire to allow undetectable and unauditable mass surveillance, which may be a requirement in exceptional scenarios such as within government departments processing classified information. However, in the vast majority of cases the properties that MIKEY-SAKKE offers are actively harmful for security. It creates a vulnerable single point of failure, which would require huge effort, skill and cost to secure ­ requiring resource beyond the capability of most companies. Better options for voice encryption exist today, though they are not perfect either. In particular, more work is needed on providing scalable and usable protection against man-in-the-middle attacks, and protection of metadata for contact discovery and calls. More broadly, designers of protocols and systems need to appreciate the ethical consequences of their actions in terms of the political and power structures which naturally follow from their use. MIKEY-SAKKE is the latest example to raise questions over the policy of many governments, including the UK, to put intelligence agencies in charge of protecting companies and individuals from spying, given the conflict of interest it creates.

And GCHQ previously rejected a more secure standard, MIKEY-IBAKE, because it didn’t allow undetectable spying.

Both the NSA and GCHQ repeatedly choose surveillance over security. We need to reject that decision.

Posted on January 22, 2016 at 2:23 PMView Comments

Sidebar photo of Bruce Schneier by Joe MacInnis.