Tag Archives: academicpapers

The Cost of Cybercrime

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2019/06/the_cost_of_cyb_1.html

Really interesting paper calculating the worldwide cost of cybercrime:

Abstract: In 2012 we presented the first systematic study of the costs of cybercrime. In this paper,we report what has changed in the seven years since. The period has seen major platform evolution, with the mobile phone replacing the PC and laptop as the consumer terminal of choice, with Android replacing Windows, and with many services moving to the cloud.The use of social networks has become extremely widespread. The executive summary is that about half of all property crime, by volume and by value, is now online. We hypothesised in 2012 that this might be so; it is now established by multiple victimisation studies.Many cybercrime patterns appear to be fairly stable, but there are some interesting changes.Payment fraud, for example, has more than doubled in value but has fallen slightly as a proportion of payment value; the payment system has simply become bigger, and slightly more efficient. Several new cybercrimes are significant enough to mention, including business email compromise and crimes involving cryptocurrencies. The move to the cloud means that system misconfiguration may now be responsible for as many breaches as phishing. Some companies have suffered large losses as a side-effect of denial-of-service worms released by state actors, such as NotPetya; we have to take a view on whether they count as cybercrime.The infrastructure supporting cybercrime, such as botnets, continues to evolve, and specific crimes such as premium-rate phone scams have evolved some interesting variants. The over-all picture is the same as in 2012: traditional offences that are now technically ‘computercrimes’ such as tax and welfare fraud cost the typical citizen in the low hundreds of Euros/dollars a year; payment frauds and similar offences, where the modus operandi has been completely changed by computers, cost in the tens; while the new computer crimes cost in the tens of cents. Defending against the platforms used to support the latter two types of crime cost citizens in the tens of dollars. Our conclusions remain broadly the same as in 2012:it would be economically rational to spend less in anticipation of cybercrime (on antivirus, firewalls, etc.) and more on response. We are particularly bad at prosecuting criminals who operate infrastructure that other wrongdoers exploit. Given the growing realisation among policymakers that crime hasn’t been falling over the past decade, merely moving online, we might reasonably hope for better funded and coordinated law-enforcement action.

Richard Clayton gave a presentation on this yesterday at WEIS. His final slide contained a summary.

  • Payment fraud is up, but credit card sales are up even more — so we’re winning.
  • Cryptocurrencies are enabling new scams, but the bit money is still being list in more traditional investment fraud.

  • Telcom fraud is down, basically because Skype is free.

  • Anti-virus fraud has almost disappeared, but tech support scams are growing very rapidly.

  • The big money is still in tax fraud, welfare fraud, VAT fraud, and so on.

  • We spend more money on cyber defense than we do on the actual losses.

  • Criminals largely act with impunity. They don’t believe they will get caught, and mostly that’s correct.

Bottom line: the technology has changed a lot since 2012, but the economic considerations remain unchanged.

Fraudulent Academic Papers

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2019/05/fraudulent_acad.html

The term “fake news” has lost much of its meaning, but it describes a real and dangerous Internet trend. Because it’s hard for many people to differentiate a real news site from a fraudulent one, they can be hoodwinked by fictitious news stories pretending to be real. The result is that otherwise reasonable people believe lies.

The trends fostering fake news are more general, though, and we need to start thinking about how it could affect different areas of our lives. In particular, I worry about how it will affect academia. In addition to fake news, I worry about fake research.

An example of this seems to have happened recently in the cryptography field. SIMON is a block cipher designed by the National Security Agency (NSA) and made public in 2013. It’s a general design optimized for hardware implementation, with a variety of block sizes and key lengths. Academic cryptanalysts have been trying to break the cipher since then, with some pretty good results, although the NSA’s specified parameters are still immune to attack. Last week, a paper appeared on the International Association for Cryptologic Research (IACR) ePrint archive purporting to demonstrate a much more effective break of SIMON, one that would affect actual implementations. The paper was sufficiently weird, the authors sufficiently unknown and the details of the attack sufficiently absent, that the editors took it down a few days later. No harm done in the end.

In recent years, there has been a push to speed up the process of disseminating research results. Instead of the laborious process of academic publication, researchers have turned to faster online publishing processes, preprint servers, and simply posting research results. The IACR ePrint archive is one of those alternatives. This has all sorts of benefits, but one of the casualties is the process of peer review. As flawed as that process is, it does help ensure the accuracy of results. (Of course, bad papers can still make it through the process. We’re still dealing with the aftermath of a flawed, and now retracted, Lancet paper linking vaccines with autism.)

Like the news business, academic publishing is subject to abuse. We can only speculate the motivations of the three people who are listed as authors on the SIMON paper, but you can easily imagine better-executed and more nefarious scenarios. In a world of competitive research, one group might publish a fake result to throw other researchers off the trail. It might be a company trying to gain an advantage over a potential competitor, or even a country trying to gain an advantage over another country.

Reverting to a slower and more accurate system isn’t the answer; the world is just moving too fast for that. We need to recognize that fictitious research results can now easily be injected into our academic publication system, and tune our skepticism meters accordingly.

This essay previously appeared on Lawfare.com.

Fingerprinting iPhones

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2019/05/fingerprinting_7.html

This clever attack allows someone to uniquely identify a phone when you visit a website, based on data from the accelerometer, gyroscope, and magnetometer sensors.

We have developed a new type of fingerprinting attack, the calibration fingerprinting attack. Our attack uses data gathered from the accelerometer, gyroscope and magnetometer sensors found in smartphones to construct a globally unique fingerprint. Overall, our attack has the following advantages:

  • The attack can be launched by any website you visit or any app you use on a vulnerable device without requiring any explicit confirmation or consent from you.
  • The attack takes less than one second to generate a fingerprint.
  • The attack can generate a globally unique fingerprint for iOS devices.
  • The calibration fingerprint never changes, even after a factory reset.
  • The attack provides an effective means to track you as you browse across the web and move between apps on your phone.

* Following our disclosure, Apple has patched this vulnerability in iOS 12.2.

Research paper.

The Concept of "Return on Data"

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2019/05/the_concept_of_.html

This law review article by Noam Kolt, titled “Return on Data,” proposes an interesting new way of thinking of privacy law.

Abstract: Consumers routinely supply personal data to technology companies in exchange for services. Yet, the relationship between the utility (U) consumers gain and the data (D) they supply — “return on data” (ROD) — remains largely unexplored. Expressed as a ratio, ROD = U / D. While lawmakers strongly advocate protecting consumer privacy, they tend to overlook ROD. Are the benefits of the services enjoyed by consumers, such as social networking and predictive search, commensurate with the value of the data extracted from them? How can consumers compare competing data-for-services deals? Currently, the legal frameworks regulating these transactions, including privacy law, aim primarily to protect personal data. They treat data protection as a standalone issue, distinct from the benefits which consumers receive. This article suggests that privacy concerns should not be viewed in isolation, but as part of ROD. Just as companies can quantify return on investment (ROI) to optimize investment decisions, consumers should be able to assess ROD in order to better spend and invest personal data. Making data-for-services transactions more transparent will enable consumers to evaluate the merits of these deals, negotiate their terms and make more informed decisions. Pivoting from the privacy paradigm to ROD will both incentivize data-driven service providers to offer consumers higher ROD, as well as create opportunities for new market entrants.

Cryptanalysis of SIMON-32/64

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2019/05/cryptanalysis_o_4.html

A weird paper was posted on the Cryptology ePrint Archive (working link is via the Wayback Machine), claiming an attack against the NSA-designed cipher SIMON. You can read some commentary about it here. Basically, the authors claimed an attack so devastating that they would only publish a zero-knowledge proof of their attack. Which they didn’t. Nor did they publish anything else of interest, near as I can tell.

The paper has since been deleted from the ePrint Archive, which feels like the correct decision on someone’s part.

Cryptanalyzing a Pair of Russian Encryption Algorithms

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2019/05/cryptanalyzing_.html

A pair of Russia-designed cryptographic algorithms — the Kuznyechik block cipher and the Streebog hash function — have the same flawed S-box that is almost certainly an intentional backdoor. It’s just not the kind of mistake you make by accident, not in 2014.

Defending Democracies Against Information Attacks

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2019/04/defending_democ.html

To better understand influence attacks, we proposed an approach that models democracy itself as an information system and explains how democracies are vulnerable to certain forms of information attacks that autocracies naturally resist. Our model combines ideas from both international security and computer security, avoiding the limitations of both in explaining how influence attacks may damage democracy as a whole.

Our initial account is necessarily limited. Building a truly comprehensive understanding of democracy as an information system will be a Herculean labor, involving the collective endeavors of political scientists and theorists, computer scientists, scholars of complexity, and others.

In this short paper, we undertake a more modest task: providing policy advice to improve the resilience of democracy against these attacks. Specifically, we can show how policy makers not only need to think about how to strengthen systems against attacks, but also need to consider how these efforts intersect with public beliefs­ — or common political knowledge­ — about these systems, since public beliefs may themselves be an important vector for attacks.

In democracies, many important political decisions are taken by ordinary citizens (typically, in electoral democracies, by voting for political representatives). This means that citizens need to have some shared understandings about their political system, and that the society needs some means of generating shared information regarding who their citizens are and what they want. We call this common political knowledge, and it is largely generated through mechanisms of social aggregation (and the institutions that implement them), such as voting, censuses, and the like. These are imperfect mechanisms, but essential to the proper functioning of democracy. They are often compromised or non-existent in autocratic regimes, since they are potentially threatening to the rulers.

In modern democracies, the most important such mechanism is voting, which aggregates citizens’ choices over competing parties and politicians to determine who is to control executive power for a limited period. Another important mechanism is the census process, which play an important role in the US and in other democracies, in providing broad information about the population, in shaping the electoral system (through the allocation of seats in the House of Representatives), and in policy making (through the allocation of government spending and resources). Of lesser import are public commenting processes, through which individuals and interest groups can comment on significant public policy and regulatory decisions.

All of these systems are vulnerable to attack. Elections are vulnerable to a variety of illegal manipulations, including vote rigging. However, many kinds of manipulation are currently legal in the US, including many forms of gerrymandering, gimmicking voting time, allocating polling booths and resources so as to advantage or disadvantage particular populations, imposing onerous registration and identity requirements, and so on.

Censuses may be manipulated through the provision of bogus information or, more plausibly, through the skewing of policy or resources so that some populations are undercounted. Many of the political battles over the census over the past few decades have been waged over whether the census should undertake statistical measures to counter undersampling bias for populations who are statistically less likely to return census forms, such as minorities and undocumented immigrants. Current efforts to include a question about immigration status may make it less likely that undocumented or recent immigrants will return completed forms.

Finally, public commenting systems too are vulnerable to attacks intended to misrepresent the support for or opposition to specific proposals, including the formation of astroturf (artificial grassroots) groups and the misuse of fake or stolen identities in large-scale mail, fax, email or online commenting systems.

All these attacks are relatively well understood, even if policy choices might be improved by a better understanding of their relationship to shared political knowledge. For example, some voting ID requirements are rationalized through appeals to security concerns about voter fraud. While political scientists have suggested that these concerns are largely unwarranted, we currently lack a framework for evaluating the trade-offs, if any. Computer security concepts such as confidentiality, integrity, and availability could be combined with findings from political science and political theory to provide such a framework.

Even so, the relationship between social aggregation institutions and public beliefs is far less well understood by policy makers. Even when social aggregation mechanisms and institutions are robust against direct attacks, they may be vulnerable to more indirect attacks aimed at destabilizing public beliefs about them.

Democratic societies are vulnerable to (at least) two kinds of knowledge attacks that autocratic societies are not. First are flooding attacks that create confusion among citizens about what other citizens believe, making it far more difficult for them to organize among themselves. Second are confidence attacks. These attempt to undermine public confidence in the institutions of social aggregation, so that their results are no longer broadly accepted as legitimate representations of the citizenry.

Most obviously, democracies will function poorly when citizens do not believe that voting is fair. This makes democracies vulnerable to attacks aimed at destabilizing public confidence in voting institutions. For example, some of Russia’s hacking efforts against the 2016 presidential election were designed to undermine citizens’ confidence in the result. Russian hacking attacks against Ukraine, which targeted the systems through which election results were reported out, were intended to create confusion among voters about what the outcome actually was. Similarly, the “Guccifer 2.0” hacking identity, which has been attributed to Russian military intelligence, sought to suggest that the US electoral system had been compromised by the Democrats in the days immediately before the presidential vote. If, as expected, Donald Trump had lost the election, these claims could have been combined with the actual evidence of hacking to create the appearance that the election was fundamentally compromised.

Similar attacks against the perception of fairness are likely to be employed against the 2020 US census. Should efforts to include a citizenship question fail, some political actors who are disadvantaged by demographic changes such as increases in foreign-born residents and population shift from rural to urban and suburban areas will mount an effort to delegitimize the census results. Again, the genuine problems with the census, which include not only the citizenship question controversy but also serious underfunding, may help to bolster these efforts.

Mechanisms that allow interested actors and ordinary members of the public to comment on proposed policies are similarly vulnerable. For example, the Federal Communication Commission (FCC) announced in 2017 that it was proposing to repeal its net neutrality ruling. Interest groups backing the FCC rollback correctly anticipated a widespread backlash from a politically active coalition of net neutrality supporters. The result was warfare through public commenting. More than 22 million comments were filed, most of which appeared to be either automatically generated or form letters. Millions of these comments were apparently fake, and attached unsuspecting people’s names and email addresses to comments supporting the FCC’s repeal efforts. The vast majority of comments that were not either form letters or automatically generated opposed the FCC’s proposed ruling. The furor around the commenting process was magnified by claims from inside the FCC (later discredited) that the commenting process had also been subjected to a cyberattack.

We do not yet know the identity and motives of the actors behind the flood of fake comments, although the New York State Attorney-General’s office has issued subpoenas for records from a variety of lobbying and advocacy organizations. However, by demonstrating that the commenting process was readily manipulated, the attack made it less likely that the apparently genuine comments of those opposing the FCC’s proposed ruling would be treated as useful evidence of what the public believed. The furor over purported cyberattacks, and the FCC’s unwillingness itself to investigate the attack, have further undermined confidence in an online commenting system that was intended to make the FCC more open to the US public.

We do not know nearly enough about how democracies function as information systems. Generating a better understanding is itself a major policy challenge, which will require substantial resources and, even more importantly, common understandings and shared efforts across a variety of fields of knowledge that currently don’t really engage with each other.

However, even this basic sketch of democracy’s informational aspects can provide policy makers with some key lessons. The most important is that it may be as important to bolster shared public beliefs about key institutions such as voting, public commenting, and census taking against attack, as to bolster the mechanisms and related institutions themselves.

Specifically, many efforts to mitigate attacks against democratic systems begin with spreading public awareness and alarm about their vulnerabilities. This has the benefit of increasing awareness about real problems, but it may ­ especially if exaggerated for effect ­ damage public confidence in the very social aggregation institutions it means to protect. This may mean, for example, that public awareness efforts about Russian hacking that are based on flawed analytic techniques may themselves damage democracy by exaggerating the consequences of attacks.

More generally, this poses important challenges for policy efforts to secure social aggregation institutions against attacks. How can one best secure the systems themselves without damaging public confidence in them? At a minimum, successful policy measures will not simply identify problems in existing systems, but provide practicable, publicly visible, and readily understandable solutions to mitigate them.

We have focused on the problem of confidence attacks in this short essay, because they are both more poorly understood and more profound than flooding attacks. Given historical experience, democracy can probably survive some amount of disinformation about citizens’ beliefs better than it can survive attacks aimed at its core institutions of aggregation. Policy makers need a better understanding of the relationship between political institutions and social beliefs: specifically, the importance of the social aggregation institutions that allow democracies to understand themselves.

There are some low-hanging fruit. Very often, hardening these institutions against attacks on their confidence will go hand in hand with hardening them against attacks more generally. Thus, for example, reforms to voting that require permanent paper ballots and random auditing would not only better secure voting against manipulation, but would have moderately beneficial consequences for public beliefs too.

There are likely broadly similar solutions for public commenting systems. Here, the informational trade-offs are less profound than for voting, since there is no need to balance the requirement for anonymity (so that no-one can tell who voted for who ex post) against other requirements (to ensure that no-one votes twice or more, no votes are changed and so on). Instead, the balance to be struck is between general ease of access and security, making it easier, for example, to leverage secondary sources to validate identity.

Both the robustness of and public confidence in the US census and the other statistical systems that guide the allocation of resources could be improved by insulating them better from political control. For example, a similar system could be used to appoint the director of the census to that for the US Comptroller-General, requiring bipartisan agreement for appointment, and making it hard to exert post-appointment pressure on the official.

Our arguments also illustrate how some well-intentioned efforts to combat social influence operations may have perverse consequences for general social beliefs. The perception of security is at least as important as the reality of security, and any defenses against information attacks need to address both.

However, we need far better developed intellectual tools if we are to properly understand the trade-offs, instead of proposing clearly beneficial policies, and avoiding straightforward mistakes. Forging such tools will require computer security specialists to start thinking systematically about public beliefs as an integral part of the systems that they seek to defend. It will mean that more military oriented cybersecurity specialists need to think deeply about the functioning of democracy and the capacity of internal as well as external actors to disrupt it, rather than reaching for their standard toolkit of state-level deterrence tools. Finally, specialists in the workings of democracy have to learn how to think about democracy and its trade-offs in specifically informational terms.

This essay was written with Henry Farrell, and has previously appeared on Defusing Disinfo.

Stealing Ethereum by Guessing Weak Private Keys

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2019/04/stealing_ethere.html

Someone is stealing millions of dollars worth of Ethereum by guessing users’ private keys. Normally this should be impossible, but lots of keys seem to be very weak. Researchers are unsure how those weak keys are being generated and used.

Their paper is here.

Vulnerabilities in the WPA3 Wi-Fi Security Protocol

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2019/04/vulnerabilities_7.html

Researchers have found several vulnerabilities in the WPA3 Wi-Fi security protocol:

The design flaws we discovered can be divided in two categories. The first category consists of downgrade attacks against WPA3-capable devices, and the second category consists of weaknesses in the Dragonfly handshake of WPA3, which in the Wi-Fi standard is better known as the Simultaneous Authentication of Equals (SAE) handshake. The discovered flaws can be abused to recover the password of the Wi-Fi network, launch resource consumption attacks, and force devices into using weaker security groups. All attacks are against home networks (i.e. WPA3-Personal), where one password is shared among all users.

News article. Research paper: “Dragonblood: A Security Analysis of WPA3’s SAE Handshake“:

Abstract: The WPA3 certification aims to secure Wi-Fi networks, and provides several advantages over its predecessor WPA2, such as protection against offline dictionary attacks and forward secrecy. Unfortunately, we show that WPA3 is affected by several design flaws,and analyze these flaws both theoretically and practically. Most prominently, we show that WPA3’s Simultaneous Authentication of Equals (SAE) handshake, commonly known as Dragonfly, is affected by password partitioning attacks. These attacks resemble dictionary attacks and allow an adversary to recover the password by abusing timing or cache-based side-channel leaks. Our side-channel attacks target the protocol’s password encoding method. For instance, our cache-based attack exploits SAE’s hash-to-curve algorithm. The resulting attacks are efficient and low cost: brute-forcing all 8-character lowercase password requires less than 125$in Amazon EC2 instances. In light of ongoing standardization efforts on hash-to-curve, Password-Authenticated Key Exchanges (PAKEs), and Dragonfly as a TLS handshake, our findings are also of more general interest. Finally, we discuss how to mitigate our attacks in a backwards-compatible manner, and explain how minor changes to the protocol could have prevented most of our attack

Maliciously Tampering with Medical Imagery

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2019/04/maliciously_tam.html

In what I am sure is only a first in many similar demonstrations, researchers are able to add or remove cancer signs from CT scans. The results easily fool radiologists.

I don’t think the medical device industry has thought at all about data integrity and authentication issues. In a world where sensor data of all kinds is undetectably manipulatable, they’re going to have to start.

Research paper. Slashdot thread.

Adversarial Machine Learning against Tesla’s Autopilot

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2019/04/adversarial_mac.html

Researchers have been able to fool Tesla’s autopilot in a variety of ways, including convincing it to drive into oncoming traffic. It requires the placement of stickers on the road.

Abstract: Keen Security Lab has maintained the security research work on Tesla vehicle and shared our research results on Black Hat USA 2017 and 2018 in a row. Based on the ROOT privilege of the APE (Tesla Autopilot ECU, software version 18.6.1), we did some further interesting research work on this module. We analyzed the CAN messaging functions of APE, and successfully got remote control of the steering system in a contact-less way. We used an improved optimization algorithm to generate adversarial examples of the features (autowipers and lane recognition) which make decisions purely based on camera data, and successfully achieved the adversarial example attack in the physical world. In addition, we also found a potential high-risk design weakness of the lane recognition when the vehicle is in Autosteer mode. The whole article is divided into four parts: first a brief introduction of Autopilot, after that we will introduce how to send control commands from APE to control the steering system when the car is driving. In the last two sections, we will introduce the implementation details of the autowipers and lane recognition features, as well as our adversarial example attacking methods in the physical world. In our research, we believe that we made three creative contributions:

  1. We proved that we can remotely gain the root privilege of APE and control the steering system.
  2. We proved that we can disturb the autowipers function by using adversarial examples in the physical world.
  3. We proved that we can mislead the Tesla car into the reverse lane with minor changes on the road.

You can see the stickers in this photo. They’re unobtrusive.

This is machine learning’s big problem, and I think solving it is a lot harder than many believe.

Recovering Smartphone Typing from Microphone Sounds

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2019/04/recovering_smar.html

Yet another side-channel attack on smartphones: “Hearing your touch: A new acoustic side channel on smartphones,” by Ilia Shumailov, Laurent Simon, Jeff Yan, and Ross Anderson.

Abstract: We present the first acoustic side-channel attack that recovers what users type on the virtual keyboard of their touch-screen smartphone or tablet. When a user taps the screen with a finger, the tap generates a sound wave that propagates on the screen surface and in the air. We found the device’s microphone(s) can recover this wave and “hear” the finger’s touch, and the wave’s distortions are characteristic of the tap’s location on the screen. Hence, by recording audio through the built-in microphone(s), a malicious app can infer text as the user enters it on their device. We evaluate the effectiveness of the attack with 45 participants in a real-world environment on an Android tablet and an Android smartphone. For the tablet, we recover 61% of 200 4-digit PIN-codes within 20 attempts, even if the model is not trained with the victim’s data. For the smartphone, we recover 9 words of size 7-13 letters with 50 attempts in a common side-channel attack benchmark. Our results suggest that it not always sufficient to rely on isolation mechanisms such as TrustZone to protect user input. We propose and discuss hardware, operating-system and application-level mechanisms to block this attack more effectively. Mobile devices may need a richer capability model, a more user-friendly notification system for sensor usage and a more thorough evaluation of the information leaked by the underlying hardware.

Blog post.

Friday Squid Blogging: New Research on Squid Camouflage

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2019/03/friday_squid_bl_669.html

From the New York Times:

Now, a paper published last week in Nature Communications suggests that their chromatophores, previously thought to be mainly pockets of pigment embedded in their skin, are also equipped with tiny reflectors made of proteins. These reflectors aid the squid to produce such a wide array of colors, including iridescent greens and blues, within a second of passing in front of a new background. The research reveals that by using tricks found in other parts of the animal kingdom — like shimmering butterflies and peacocks — squid are able to combine multiple approaches to produce their vivid camouflage.

Researchers studied Doryteuthis pealeii, or the longfin squid.

As usual, you can also use this squid post to talk about the security stories in the news that I haven’t covered.

Read my blog posting guidelines here.

I Was Cited in a Court Decision

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2019/03/i_was_cited_in_.html

An article I co-wrote — my first law journal article — was cited by the Massachusetts Supreme Judicial Court — the state supreme court — in a case on compelled decryption.

Here’s the first, in footnote 1:

We understand the word “password” to be synonymous with other terms that cell phone users may be familiar with, such as Personal Identification Number or “passcode.” Each term refers to the personalized combination of letters or digits that, when manually entered by the user, “unlocks” a cell phone. For simplicity, we use “password” throughout. See generally, Kerr & Schneier, Encryption Workarounds, 106 Geo. L.J. 989, 990, 994, 998 (2018).

And here’s the second, in footnote 5:

We recognize that ordinary cell phone users are likely unfamiliar with the complexities of encryption technology. For instance, although entering a password “unlocks” a cell phone, the password itself is not the “encryption key” that decrypts the cell phone’s contents. See Kerr & Schneier, supra at 995. Rather, “entering the [password] decrypts the [encryption] key, enabling the key to be processed and unlocking the phone. This two-stage process is invisible to the casual user.” Id. Because the technical details of encryption technology do not play a role in our analysis, they are not worth belaboring. Accordingly, we treat the entry of a password as effectively decrypting the contents of a cell phone. For a more detailed discussion of encryption technology, see generally Kerr & Schneier, supra.

Digital Signatures in PDFs Are Broken

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2019/03/digital_signatu.html

Researchers have demonstrated spoofing of digital signatures in PDF files.

This would matter more if PDF digital signatures were widely used. Still, the researchers have worked with the various companies that make PDF readers to close the vulnerabilities. You should update your software.

Details are here.

News article.

Friday Squid Blogging: A Tracking Device for Squid

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2019/02/friday_squid_bl_664.html

Really:

After years of “making do” with the available technology for his squid studies, Mooney created a versatile tag that allows him to research squid behavior. With the help of Kakani Katija, an engineer adapting the tag for jellyfish at California’s Monterey Bay Aquarium Research Institute (MBARI), Mooney’s team is creating a replicable system flexible enough to work across a range of soft-bodied marine animals. As Mooney and Katija refine the tags, they plan to produce an adaptable, open-source package that scientists researching other marine invertebrates can also use.

As usual, you can also use this squid post to talk about the security stories in the news that I haven’t covered.

Read my blog posting guidelines here.

Blockchain and Trust

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2019/02/blockchain_and_.html

In his 2008 white paper that first proposed bitcoin, the anonymous Satoshi Nakamoto concluded with: “We have proposed a system for electronic transactions without relying on trust.” He was referring to blockchain, the system behind bitcoin cryptocurrency. The circumvention of trust is a great promise, but it’s just not true. Yes, bitcoin eliminates certain trusted intermediaries that are inherent in other payment systems like credit cards. But you still have to trust bitcoin — and everything about it.

Much has been written about blockchains and how they displace, reshape, or eliminate trust. But when you analyze both blockchain and trust, you quickly realize that there is much more hype than value. Blockchain solutions are often much worse than what they replace.

First, a caveat. By blockchain, I mean something very specific: the data structures and protocols that make up a public blockchain. These have three essential elements. The first is a distributed (as in multiple copies) but centralized (as in there’s only one) ledger, which is a way of recording what happened and in what order. This ledger is public, meaning that anyone can read it, and immutable, meaning that no one can change what happened in the past.

The second element is the consensus algorithm, which is a way to ensure all the copies of the ledger are the same. This is generally called mining; a critical part of the system is that anyone can participate. It is also distributed, meaning that you don’t have to trust any particular node in the consensus network. It can also be extremely expensive, both in data storage and in the energy required to maintain it. Bitcoin has the most expensive consensus algorithm the world has ever seen, by far.

Finally, the third element is the currency. This is some sort of digital token that has value and is publicly traded. Currency is a necessary element of a blockchain to align the incentives of everyone involved. Transactions involving these tokens are stored on the ledger.

Private blockchains are completely uninteresting. (By this, I mean systems that use the blockchain data structure but don’t have the above three elements.) In general, they have some external limitation on who can interact with the blockchain and its features. These are not anything new; they’re distributed append-only data structures with a list of individuals authorized to add to it. Consensus protocols have been studied in distributed systems for more than 60 years. Append-only data structures have been similarly well covered. They’re blockchains in name only, and — as far as I can tell — the only reason to operate one is to ride on the blockchain hype.

All three elements of a public blockchain fit together as a single network that offers new security properties. The question is: Is it actually good for anything? It’s all a matter of trust.

Trust is essential to society. As a species, humans are wired to trust one another. Society can’t function without trust, and the fact that we mostly don’t even think about it is a measure of how well trust works.

The word “trust” is loaded with many meanings. There’s personal and intimate trust. When we say we trust a friend, we mean that we trust their intentions and know that those intentions will inform their actions. There’s also the less intimate, less personal trust — we might not know someone personally, or know their motivations, but we can trust their future actions. Blockchain enables this sort of trust: We don’t know any bitcoin miners, for example, but we trust that they will follow the mining protocol and make the whole system work.

Most blockchain enthusiasts have a unnaturally narrow definition of trust. They’re fond of catchphrases like “in code we trust,” “in math we trust,” and “in crypto we trust.” This is trust as verification. But verification isn’t the same as trust.

In 2012, I wrote a book about trust and security, Liars and Outliers. In it, I listed four very general systems our species uses to incentivize trustworthy behavior. The first two are morals and reputation. The problem is that they scale only to a certain population size. Primitive systems were good enough for small communities, but larger communities required delegation, and more formalism.

The third is institutions. Institutions have rules and laws that induce people to behave according to the group norm, imposing sanctions on those who do not. In a sense, laws formalize reputation. Finally, the fourth is security systems. These are the wide varieties of security technologies we employ: door locks and tall fences, alarm systems and guards, forensics and audit systems, and so on.

These four elements work together to enable trust. Take banking, for example. Financial institutions, merchants, and individuals are all concerned with their reputations, which prevents theft and fraud. The laws and regulations surrounding every aspect of banking keep everyone in line, including backstops that limit risks in the case of fraud. And there are lots of security systems in place, from anti-counterfeiting technologies to internet-security technologies.

In his 2018 book, Blockchain and the New Architecture of Trust, Kevin Werbach outlines four different “trust architectures.” The first is peer-to-peer trust. This basically corresponds to my morals and reputational systems: pairs of people who come to trust each other. His second is leviathan trust, which corresponds to institutional trust. You can see this working in our system of contracts, which allows parties that don’t trust each other to enter into an agreement because they both trust that a government system will help resolve disputes. His third is intermediary trust. A good example is the credit card system, which allows untrusting buyers and sellers to engage in commerce. His fourth trust architecture is distributed trust. This is emergent trust in the particular security system that is blockchain.

What blockchain does is shift some of the trust in people and institutions to trust in technology. You need to trust the cryptography, the protocols, the software, the computers and the network. And you need to trust them absolutely, because they’re often single points of failure.

When that trust turns out to be misplaced, there is no recourse. If your bitcoin exchange gets hacked, you lose all of your money. If your bitcoin wallet gets hacked, you lose all of your money. If you forget your login credentials, you lose all of your money. If there’s a bug in the code of your smart contract, you lose all of your money. If someone successfully hacks the blockchain security, you lose all of your money. In many ways, trusting technology is harder than trusting people. Would you rather trust a human legal system or the details of some computer code you don’t have the expertise to audit?

Blockchain enthusiasts point to more traditional forms of trust — bank processing fees, for example — as expensive. But blockchain trust is also costly; the cost is just hidden. For bitcoin, that’s the cost of the additional bitcoin mined, the transaction fees, and the enormous environmental waste.

Blockchain doesn’t eliminate the need to trust human institutions. There will always be a big gap that can’t be addressed by technology alone. People still need to be in charge, and there is always a need for governance outside the system. This is obvious in the ongoing debate about changing the bitcoin block size, or in fixing the DAO attack against Ethereum. There’s always a need to override the rules, and there’s always a need for the ability to make permanent rules changes. As long as hard forks are a possibility — that’s when the people in charge of a blockchain step outside the system to change it — people will need to be in charge.

Any blockchain system will have to coexist with other, more conventional systems. Modern banking, for example, is designed to be reversible. Bitcoin is not. That makes it hard to make the two compatible, and the result is often an insecurity. Steve Wozniak was scammed out of $70K in bitcoin because he forgot this.

Blockchain technology is often centralized. Bitcoin might theoretically be based on distributed trust, but in practice, that’s just not true. Just about everyone using bitcoin has to trust one of the few available wallets and use one of the few available exchanges. People have to trust the software and the operating systems and the computers everything is running on. And we’ve seen attacks against wallets and exchanges. We’ve seen Trojans and phishing and password guessing. Criminals have even used flaws in the system that people use to repair their cell phones to steal bitcoin.

Moreover, in any distributed trust system, there are backdoor methods for centralization to creep back in. With bitcoin, there are only a few miners of consequence. There’s one company that provides most of the mining hardware. There are only a few dominant exchanges. To the extent that most people interact with bitcoin, it is through these centralized systems. This also allows for attacks against blockchain-based systems.

These issues are not bugs in current blockchain applications, they’re inherent in how blockchain works. Any evaluation of the security of the system has to take the whole socio-technical system into account. Too many blockchain enthusiasts focus on the technology and ignore the rest.

To the extent that people don’t use bitcoin, it’s because they don’t trust bitcoin. That has nothing to do with the cryptography or the protocols. In fact, a system where you can lose your life savings if you forget your key or download a piece of malware is not particularly trustworthy. No amount of explaining how SHA-256 works to prevent double-spending will fix that.

Similarly, to the extent that people do use blockchains, it is because they trust them. People either own bitcoin or not based on reputation; that’s true even for speculators who own bitcoin simply because they think it will make them rich quickly. People choose a wallet for their cryptocurrency, and an exchange for their transactions, based on reputation. We even evaluate and trust the cryptography that underpins blockchains based on the algorithms’ reputation.

To see how this can fail, look at the various supply-chain security systems that are using blockchain. A blockchain isn’t a necessary feature of any of them. The reasons they’re successful is that everyone has a single software platform to enter their data in. Even though the blockchain systems are built on distributed trust, people don’t necessarily accept that. For example, some companies don’t trust the IBM/Maersk system because it’s not their blockchain.

Irrational? Maybe, but that’s how trust works. It can’t be replaced by algorithms and protocols. It’s much more social than that.

Still, the idea that blockchains can somehow eliminate the need for trust persists. Recently, I received an email from a company that implemented secure messaging using blockchain. It said, in part: “Using the blockchain, as we have done, has eliminated the need for Trust.” This sentiment suggests the writer misunderstands both what blockchain does and how trust works.

Do you need a public blockchain? The answer is almost certainly no. A blockchain probably doesn’t solve the security problems you think it solves. The security problems it solves are probably not the ones you have. (Manipulating audit data is probably not your major security risk.) A false trust in blockchain can itself be a security risk. The inefficiencies, especially in scaling, are probably not worth it. I have looked at many blockchain applications, and all of them could achieve the same security properties without using a blockchain­ — of course, then they wouldn’t have the cool name.

Honestly, cryptocurrencies are useless. They’re only used by speculators looking for quick riches, people who don’t like government-backed currencies, and criminals who want a black-market way to exchange money.

To answer the question of whether the blockchain is needed, ask yourself: Does the blockchain change the system of trust in any meaningful way, or just shift it around? Does it just try to replace trust with verification? Does it strengthen existing trust relationships, or try to go against them? How can trust be abused in the new system, and is this better or worse than the potential abuses in the old system? And lastly: What would your system look like if you didn’t use blockchain at all?

If you ask yourself those questions, it’s likely you’ll choose solutions that don’t use public blockchain. And that’ll be a good thing — especially when the hype dissipates.

This essay previously appeared on Wired.com.

EDITED TO ADD (2/11): Two commentaries on my essay.

I have wanted to write this essay for over a year. The impetus to finally do it came from an invite to speak at the Hyperledger Global Forum in December. This essay is a version of the talk I wrote for that event, made more accessible to a general audience.

It seems to be the season for blockchain takedowns. James Waldo has an excellent essay in Queue. And Nicholas Weaver gave a talk at the Enigma Conference, summarized here. It’s a shortened version of this talk.

EDITED TO ADD (2/17): Reddit thread.