Schneier on Security: Blog Entries Tagged security engineering

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New iPhone OS May Include Device-Unlocking Security

iOS 12, the next release of Apple's iPhone operating system, may include features to prevent someone from unlocking your phone without your permission:

The feature essentially forces users to unlock the iPhone with the passcode when connecting it to a USB accessory everytime the phone has not been unlocked for one hour. That includes the iPhone unlocking devices that companies such as Cellebrite or GrayShift make, which police departments all over the world use to hack into seized iPhones.

"That pretty much kills [GrayShift's product] GrayKey and Cellebrite," Ryan Duff, a security researcher who has studied iPhone and is Director of Cyber Solutions at Point3 Security, told Motherboard in an online chat. "If it actually does what it says and doesn't let ANY type of data connection happen until it's unlocked, then yes. You can't exploit the device if you can't communicate with it."

This is part of a bunch of security enhancements in iOS 12:

Other enhancements include tools for generating strong passwords, storing them in the iCloud keychain, and automatically entering them into Safari and iOS apps across all of a user's devices. Previously, standalone apps such as 1Password have done much the same thing. Now, Apple is integrating the functions directly into macOS and iOS. Apple also debuted new programming interfaces that allow users to more easily access passwords stored in third-party password managers directly from the QuickType bar. The company also announced a new feature that will flag reused passwords, an interface that autofills one-time passwords provided by authentication apps, and a mechanism for sharing passwords among nearby iOS devices, Macs, and Apple TVs.

A separate privacy enhancement is designed to prevent websites from tracking people when using Safari. It's specifically designed to prevent share buttons and comment code on webpages from tracking people's movements across the Web without permission or from collecting a device's unique settings such as fonts, in an attempt to fingerprint the device.

The last additions of note are new permission dialogues macOS Mojave will display before allowing apps to access a user's camera or microphone. The permissions are designed to thwart malicious software that surreptitiously turns on these devices in an attempt to spy on users. The new protections will largely mimic those previously available only through standalone apps such as one called Oversight, developed by security researcher Patrick Wardle. Apple said similar dialog permissions will protect the file system, mail database, message history, and backups.

Posted on June 12, 2018 at 6:23 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

Securing Elections

Elections serve two purposes. The first, and obvious, purpose is to accurately choose the winner. But the second is equally important: to convince the loser. To the extent that an election system is not transparently and auditably accurate, it fails in that second purpose. Our election systems are failing, and we need to fix them.

Today, we conduct our elections on computers. Our registration lists are in computer databases. We vote on computerized voting machines. And our tabulation and reporting is done on computers. We do this for a lot of good reasons, but a side effect is that elections now have all the insecurities inherent in computers. The only way to reliably protect elections from both malice and accident is to use something that is not hackable or unreliable at scale; the best way to do that is to back up as much of the system as possible with paper.

Recently, there have been two graphic demonstrations of how bad our computerized voting system is. In 2007, the states of California and Ohio conducted audits of their electronic voting machines. Expert review teams found exploitable vulnerabilities in almost every component they examined. The researchers were able to undetectably alter vote tallies, erase audit logs, and load malware on to the systems. Some of their attacks could be implemented by a single individual with no greater access than a normal poll worker; others could be done remotely.

Last year, the Defcon hackers' conference sponsored a Voting Village. Organizers collected 25 pieces of voting equipment, including voting machines and electronic poll books. By the end of the weekend, conference attendees had found ways to compromise every piece of test equipment: to load malicious software, compromise vote tallies and audit logs, or cause equipment to fail.

It's important to understand that these were not well-funded nation-state attackers. These were not even academics who had been studying the problem for weeks. These were bored hackers, with no experience with voting machines, playing around between parties one weekend.

It shouldn't be any surprise that voting equipment, including voting machines, voter registration databases, and vote tabulation systems, are that hackable. They're computers -- often ancient computers running operating systems no longer supported by the manufacturers -- and they don't have any magical security technology that the rest of the industry isn't privy to. If anything, they're less secure than the computers we generally use, because their manufacturers hide any flaws behind the proprietary nature of their equipment.

We're not just worried about altering the vote. Sometimes causing widespread failures, or even just sowing mistrust in the system, is enough. And an election whose results are not trusted or believed is a failed election.

Voting systems have another requirement that makes security even harder to achieve: the requirement for a secret ballot. Because we have to securely separate the election-roll system that determines who can vote from the system that collects and tabulates the votes, we can't use the security systems available to banking and other high-value applications.

We can securely bank online, but can't securely vote online. If we could do away with anonymity -- if everyone could check that their vote was counted correctly -- then it would be easy to secure the vote. But that would lead to other problems. Before the US had the secret ballot, voter coercion and vote-buying were widespread.

We can't, so we need to accept that our voting systems are insecure. We need an election system that is resilient to the threats. And for many parts of the system, that means paper.

Let's start with the voter rolls. We know they've already been targeted. In 2016, someone changed the party affiliation of hundreds of voters before the Republican primary. That's just one possibility. A well-executed attack that deletes, for example, one in five voters at random -- or changes their addresses -- would cause chaos on election day.

Yes, we need to shore up the security of these systems. We need better computer, network, and database security for the various state voter organizations. We also need to better secure the voter registration websites, with better design and better internet security. We need better security for the companies that build and sell all this equipment.

Multiple, unchangeable backups are essential. A record of every addition, deletion, and change needs to be stored on a separate system, on write-only media like a DVD. Copies of that DVD, or -- even better -- a paper printout of the voter rolls, should be available at every polling place on election day. We need to be ready for anything.

Next, the voting machines themselves. Security researchers agree that the gold standard is a voter-verified paper ballot. The easiest (and cheapest) way to achieve this is through optical-scan voting. Voters mark paper ballots by hand; they are fed into a machine and counted automatically. That paper ballot is saved, and serves as a final true record in a recount in case of problems. Touch-screen machines that print a paper ballot to drop in a ballot box can also work for voters with disabilities, as long as the ballot can be easily read and verified by the voter.

Finally, the tabulation and reporting systems. Here again we need more security in the process, but we must always use those paper ballots as checks on the computers. A manual, post-election, risk-limiting audit varies the number of ballots examined according to the margin of victory. Conducting this audit after every election, before the results are certified, gives us confidence that the election outcome is correct, even if the voting machines and tabulation computers have been tampered with. Additionally, we need better coordination and communications when incidents occur.

It's vital to agree on these procedures and policies before an election. Before the fact, when anyone can win and no one knows whose votes might be changed, it's easy to agree on strong security. But after the vote, someone is the presumptive winner -- and then everything changes. Half of the country wants the result to stand, and half wants it reversed. At that point, it's too late to agree on anything.

The politicians running in the election shouldn't have to argue their challenges in court. Getting elections right is in the interest of all citizens. Many countries have independent election commissions that are charged with conducting elections and ensuring their security. We don't do that in the US.

Instead, we have representatives from each of our two parties in the room, keeping an eye on each other. That provided acceptable security against 20th-century threats, but is totally inadequate to secure our elections in the 21st century. And the belief that the diversity of voting systems in the US provides a measure of security is a dangerous myth, because a few districts can be decisive and there are so few voting-machine vendors.

We can do better. In 2017, the Department of Homeland Security declared elections to be critical infrastructure, allowing the department to focus on securing them. On 23 March, Congress allocated $380m to states to upgrade election security.

These are good starts, but don't go nearly far enough. The constitution delegates elections to the states but allows Congress to "make or alter such Regulations". In 1845, Congress set a nationwide election day. Today, we need it to set uniform and strict election standards.

This essay originally appeared in the Guardian.

Posted on April 20, 2018 at 6:44 AMView Comments

Artificial Intelligence and the Attack/Defense Balance

Artificial intelligence technologies have the potential to upend the longstanding advantage that attack has over defense on the Internet. This has to do with the relative strengths and weaknesses of people and computers, how those all interplay in Internet security, and where AI technologies might change things.

You can divide Internet security tasks into two sets: what humans do well and what computers do well. Traditionally, computers excel at speed, scale, and scope. They can launch attacks in milliseconds and infect millions of computers. They can scan computer code to look for particular kinds of vulnerabilities, and data packets to identify particular kinds of attacks.

Humans, conversely, excel at thinking and reasoning. They can look at the data and distinguish a real attack from a false alarm, understand the attack as it's happening, and respond to it. They can find new sorts of vulnerabilities in systems. Humans are creative and adaptive, and can understand context.

Computers -- so far, at least -- are bad at what humans do well. They're not creative or adaptive. They don't understand context. They can behave irrationally because of those things.

Humans are slow, and get bored at repetitive tasks. They're terrible at big data analysis. They use cognitive shortcuts, and can only keep a few data points in their head at a time. They can also behave irrationally because of those things.

AI will allow computers to take over Internet security tasks from humans, and then do them faster and at scale. Here are possible AI capabilities:

  • Discovering new vulnerabilities­ -- and, more importantly, new types of vulnerabilities­ in systems, both by the offense to exploit and by the defense to patch, and then automatically exploiting or patching them.
  • Reacting and adapting to an adversary's actions, again both on the offense and defense sides. This includes reasoning about those actions and what they mean in the context of the attack and the environment.
  • Abstracting lessons from individual incidents, generalizing them across systems and networks, and applying those lessons to increase attack and defense effectiveness elsewhere.
  • Identifying strategic and tactical trends from large datasets and using those trends to adapt attack and defense tactics.

That's an incomplete list. I don't think anyone can predict what AI technologies will be capable of. But it's not unreasonable to look at what humans do today and imagine a future where AIs are doing the same things, only at computer speeds, scale, and scope.

Both attack and defense will benefit from AI technologies, but I believe that AI has the capability to tip the scales more toward defense. There will be better offensive and defensive AI techniques. But here's the thing: defense is currently in a worse position than offense precisely because of the human components. Present-day attacks pit the relative advantages of computers and humans against the relative weaknesses of computers and humans. Computers moving into what are traditionally human areas will rebalance that equation.

Roy Amara famously said that we overestimate the short-term effects of new technologies, but underestimate their long-term effects. AI is notoriously hard to predict, so many of the details I speculate about are likely to be wrong­ -- and AI is likely to introduce new asymmetries that we can't foresee. But AI is the most promising technology I've seen for bringing defense up to par with offense. For Internet security, that will change everything.

This essay previously appeared in the March/April 2018 issue of IEEE Security & Privacy.

Posted on March 15, 2018 at 6:16 AMView Comments

Can Consumers' Online Data Be Protected?

Everything online is hackable. This is true for Equifax's data and the federal Office of Personal Management's data, which was hacked in 2015. If information is on a computer connected to the Internet, it is vulnerable.

But just because everything is hackable doesn't mean everything will be hacked. The difference between the two is complex, and filled with defensive technologies, security best practices, consumer awareness, the motivation and skill of the hacker and the desirability of the data. The risks will be different if an attacker is a criminal who just wants credit card details ­ and doesn't care where he gets them from ­ or the Chinese military looking for specific data from a specific place.

The proper question isn't whether it's possible to protect consumer data, but whether a particular site protects our data well enough for the benefits provided by that site. And here, again, there are complications.

In most cases, it's impossible for consumers to make informed decisions about whether their data is protected. We have no idea what sorts of security measures Google uses to protect our highly intimate Web search data or our personal e-mails. We have no idea what sorts of security measures Facebook uses to protect our posts and conversations.

We have a feeling that these big companies do better than smaller ones. But we're also surprised when a lone individual publishes personal data hacked from the infidelity site, or when the North Korean government does the same with personal information in Sony's network.

Think about all the companies collecting personal data about you ­ the websites you visit, your smartphone and its apps, your Internet-connected car -- and how little you know about their security practices. Even worse, credit bureaus and data brokers like Equifax collect your personal information without your knowledge or consent.

So while it might be possible for companies to do a better job of protecting our data, you as a consumer are in no position to demand such protection.

Government policy is the missing ingredient. We need standards and a method for enforcement. We need liabilities and the ability to sue companies that poorly secure our data. The biggest reason companies don't protect our data online is that it's cheaper not to. Government policy is how we change that.

This essay appeared as half of a point/counterpoint with Priscilla Regan, in a CQ Researcher report titled "Privacy and the Internet."

Posted on February 14, 2018 at 6:43 AMView Comments

Daniel Miessler on My Writings about IoT Security

Daniel Miessler criticizes my writings about IoT security:

I know it's super cool to scream about how IoT is insecure, how it's dumb to hook up everyday objects like houses and cars and locks to the internet, how bad things can get, and I know it's fun to be invited to talk about how everything is doom and gloom.

I absolutely respect Bruce Schneier a lot for what he's contributed to InfoSec, which makes me that much more disappointed with this kind of position from him.

InfoSec is full of those people, and it's beneath people like Bruce to add their voices to theirs. Everyone paying attention already knows it's going to be a soup sandwich -- a carnival of horrors -- a tragedy of mistakes and abuses of trust.

It's obvious. Not interesting. Not novel. Obvious. But obvious or not, all these things are still going to happen.

I actually agree with everything in his essay. "We should obviously try to minimize the risks, but we don't do that by trying to shout down the entire enterprise." Yes, definitely.

I don't think the IoT must be stopped. I do think that the risks are considerable, and will increase as these systems become more pervasive and susceptible to class breaks. And I'm trying to write a book that will help navigate this. I don't think I'm the prophet of doom, and don't want to come across that way. I'll give the manuscript another read with that in mind.

Posted on January 9, 2018 at 3:26 PMView Comments

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Schneier on Security is a personal website. Opinions expressed are not necessarily those of IBM Resilient.