Tag Archives: Privacy

San Francisco Police Illegally Spying on Protesters

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2022/01/san-francisco-police-illegally-spying-on-protesters.html

Last summer, the San Francisco police illegally used surveillance cameras at the George Floyd protests. The EFF is suing the police:

This surveillance invaded the privacy of protesters, targeted people of color, and chills and deters participation and organizing for future protests. The SFPD also violated San Francisco’s new Surveillance Technology Ordinance. It prohibits city agencies like the SFPD from acquiring, borrowing, or using surveillance technology, without prior approval from the city’s Board of Supervisors, following an open process that includes public participation. Here, the SFPD went through no such process before spying on protesters with this network of surveillance cameras.

It’s feels like a pretty easy case. There’s a law, and the SF police didn’t follow it.

Tech billionaire Chris Larsen is on the side of the police. He thinks that the surveillance is a good thing, and wrote an op-ed defending it.

I wouldn’t be writing about this at all except that Chris is a board member of EPIC, and used his EPIC affiliation in the op-ed to bolster his own credentials. (Bizarrely, he linked to an EPIC page that directly contradicts his position.) In his op-ed, he mischaracterized the EFF’s actions and the facts of the lawsuit. It’s a mess.

The plaintiffs in the lawsuit wrote a good rebuttal to Larsen’s piece. And this week, EPIC published what is effectively its own rebuttal:

One of the fundamental principles that underlies EPIC’s work (and the work of many other groups) on surveillance oversight is that individuals should have the power to decide whether surveillance tools are used in their communities and to impose limits on their use. We have fought for years to shed light on the development, procurement, and deployment of such technologies and have worked to ensure that they are subject to independent oversight through hearings, legal challenges, petitions, and other public forums. The CCOPS model, which was developed by ACLU affiliates and other coalition partners in California and implemented through the San Francisco ordinance, is a powerful mechanism to enable public oversight of dangerous surveillance tools. The access, retention, and use policies put in place by the neighborhood business associations operating these networks provide necessary, but not sufficient, protections against abuse. Strict oversight is essential to promote both privacy and community safety, which includes freedom from arbitrary police action and the freedom to assemble.

So far, EPIC has not done anything about Larsen still being on its board. (Others have criticized them for keeping him on.) I don’t know if I have an opinion on this. Larsen has done good work on financial privacy regulations, which is a good thing. But he seems to be funding all these surveillance cameras in San Francisco, which is really bad.

UK Government to Launch PR Campaign Undermining End-to-End Encryption

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2022/01/uk-government-to-launch-pr-campaign-undermining-end-to-end-encryption.html

Rolling Stone is reporting that the UK government has hired the M&C Saatchi advertising agency to launch an anti-encryption advertising campaign. Presumably they’ll lean heavily on the “think of the children!” rhetoric we’re seeing in this current wave of the crypto wars. The technical eavesdropping mechanisms have shifted to client-side scanning, which won’t actually help — but since that’s not really the point, it’s not argued on its merits.

Using Foreign Nationals to Bypass US Surveillance Restrictions

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2022/01/using-foreign-nationals-to-bypass-us-surveillance-restrictions.html

Remember when the US and Australian police surreptitiously owned and operated the encrypted cell phone app ANOM? They arrested 800 people in 2021 based on that operation.

New documents received by Motherboard show that over 100 of those phones were shipped to users in the US, far more than previously believed.

What’s most interesting to me about this new information is how the US used the Australians to get around domestic spying laws:

For legal reasons, the FBI did not monitor outgoing messages from Anom devices determined to be inside the U.S. Instead, the Australian Federal Police (AFP) monitored them on behalf of the FBI, according to previously published court records. In those court records unsealed shortly before the announcement of the Anom operation, FBI Special Agent Nicholas Cheviron wrote that the FBI received Anom user data three times a week, which contained the messages of all of the users of Anom with some exceptions, including “the messages of approximately 15 Anom users in the U.S. sent to any other Anom device.”

[…]

Stewart Baker, partner at Steptoe & Johnson LLP, and Bryce Klehm, associate editor of Lawfare, previously wrote that “The ‘threat to life; standard echoes the provision of U.S. law that allows communications providers to share user data with law enforcement without legal process under 18 U.S.C. § 2702. Whether the AFP was relying on this provision of U.S. law or a more general moral imperative to take action to prevent imminent threats is not clear.” That section of law discusses the voluntary disclosure of customer communications or records.

When asked about the practice of Australian law enforcement monitoring devices inside the U.S. on behalf of the FBI, Senator Ron Wyden told Motherboard in a statement “Multiple intelligence community officials have confirmed to me, in writing, that intelligence agencies cannot ask foreign partners to conduct surveillance that the U.S. would be legally prohibited from doing itself. The FBI should follow this same standard. Allegations that the FBI outsourced warrantless surveillance of Americans to a foreign government raise troubling questions about the Justice Department’s oversight of these practices.”

I and others have long suspected that the NSA uses foreign nationals to get around restrictions that prevent it from spying on Americans. It is interesting to see the FBI using the same trick.

2021 AWS security-focused workshops

Post Syndicated from Temi Adebambo original https://aws.amazon.com/blogs/security/2021-aws-security-focused-workshops/

Every year, Amazon Web Services (AWS) looks to help our customers gain more experience and knowledge of our services through hands-on workshops. In 2021, we unfortunately couldn’t connect with you in person as much as we would have liked, so we wanted to create and share new ways to learn and build on AWS. We built and published several security-focused workshops that help you learn how to use or configure new services and features securely. Workshops are hands-on learning modules designed to teach or introduce practical skills, techniques, or concepts you can use to solve business problems.

In this blog post, we highlight the newest AWS security-focused workshops below. There are also several other workshops that were developed before 2021; you can find them on AWS Workshops, AWS Security Workshops, and AWS Samples. Here’s the list:

Data Protection and Privacy

Workshop Title

Abstract

Data discovery and classification with Amazon Macie

In this workshop, get familiar with Amazon Macie and learn to scan and classify data in your Amazon Simple Storage Service (Amazon S3) buckets. Work with Macie (data classification) and AWS Security Hub (centralized security view) to see how data in your environment is stored, and to understand any changes in S3 bucket policies that may affect your security posture. Learn to create a custom data identifier and to create and scope data discovery and classification jobs in Macie. Finally, use Macie to filter and investigate the results from the scans you create.

Scaling your encryption at rest capabilities with AWS KMS

AWS makes it easy to protect your data with encryption. This hands-on workshop provides an opportunity to dive deep into encryption at rest options with AWS. Learn AWS server-side encryption with AWS Key Management Service (AWS KMS) for services such as Amazon S3, Amazon Elastic Block Store (Amazon EBS), and Amazon Relational Database Service (Amazon RDS). Also, learn best practices for using AWS KMS across multiple accounts and Regions and how to scale while optimizing for performance.

Store, retrieve, and manage sensitive credentials in AWS Secrets Manager

In this workshop, learn how to integrate AWS Secrets Manager in your development platform, backed by serverless applications. Work through a sample application, and use Secrets Manager to retrieve credentials as well as work with attribute-based access control using tags. Also, learn how to monitor the compliance of secrets and implement incident response workflows that will rotate the secret, restore the resource policy, alert the SOC, and deny access to the offender.

Building and operating a Private Certificate Authority on AWS

This workshop covers private certificate management on AWS, employing the concepts of least privilege, separation of duties, monitoring, and automation. Participants learn operational aspects of creating a complete certificate authority (CA) hierarchy, building a simple web application, and issuing private certificates. It also covers how job functions—including CA administrators, application developers, and security administrators—can follow the principle of least privilege to perform various functions associated with certificate management. Finally, learn about IoT certificates, code-signing, and certificate templates to enable all your use cases.

Amazon S3 security and access settings and controls

Amazon S3 provides many security and access settings to help you secure your data, controls that ensure that those settings remain in place, and features to help you audit those settings and controls. This workshop walks you through these Amazon S3 capabilities and scenarios, to help you apply them for different security requirements.

Redact data as needed using Amazon S3 Object Lambda

Amazon S3 Object Lambda works with your existing applications, and allows you to add your own code using AWS Lambda functions to automatically process and transform data from Amazon S3 before returning it to an application. This enables different views of the same object depending on user identity, such as restricting access to confidential information, or disallowing access to personally identifiable information (PII) data. In this workshop, learn how to use Amazon S3 Object Lambda to modify objects during GET requests, so you no longer need to store multiple views of the same document.

Using AWS Nitro Enclaves to process highly sensitive data

In this hands-on workshop, learn how to use AWS Nitro Enclaves to isolate highly-sensitive data from your users, applications, and third-party libraries on your Amazon Elastic Compute Cloud (Amazon EC2) instances. Explore AWS Nitro Enclaves, discuss common use cases, and build and run your own enclave. During this workshop, learn about enclave isolation, cryptographic attestation, enclave image files, local Vsock communication channels, common debugging scenarios, and the enclave lifecycle.

Ransomware prevention strategies in Amazon S3

Learn how to use the protective, detective and monitoring controls in AWS to protect your data in S3 from ransomware threats. Set up Amazon GuardDuty for S3 and AWS Identity and Access Management (IAM) Access Analyzer, and learn to read and respond to findings and create IAM invariants. Create a tiered storage approach to backup and recovery, and learn to use Amazon S3 Object Lock, versioning, and replication to provide immutable storage and protect against accidental or malicious deletion.

Governance, Risk, and Compliance

Operating securely in a multi-account environment

Operating multiple AWS accounts under an organization is how many users consume AWS Cloud services. In this workshop, learn how to build foundational security monitoring in multi-account environments. Walk through an initial setup of AWS Security Hub for centralized aggregation of findings across your AWS Organizations organization. Additionally, learn how to centralize Amazon GuardDuty findings, Amazon Detective functions, AWS Identity and Access Management (IAM) Access Analyzer findings (if available), AWS Config rule evaluations, and AWS CloudTrail logs into the central security monitoring account (security tools account). Finally, implement a service control policy (SCP) that denies the ability to disable these security controls.

Building remediation workflows to simplify compliance

Automation and simplification are key to managing compliance at scale. Remediation is one of the essential elements of simplifying and managing risk. In this workshop, see how to build a remediation workflow using AWS Config and AWS Systems Manager automation. Learn how this workflow can be deployed at scale and monitored with AWS Security Hub to oversee the entire organization and how to use AWS Audit Manager to easily access evidence of risk management.

Identity and Access Management

Integrating IAM Access Analyzer into a CI/CD pipeline

Want to analyze Identity and Access Management (IAM) policies at scale? Want to help your developers write secure IAM policies? This workshop provides you the hands-on opportunity to run IAM Access Analyzer policy validation on your AWS CloudFormation templates in a continuous integration/continuous deployment (CI/CD) pipeline.

Data perimeter workshop

In this workshop, learn how to create a data perimeter by building controls that allow access to data only from expected network locations and by trusted identities. The workshop consists of five modules, each designed to illustrate a different Identity and Access Management (IAM) or network control. Learn where and how to implement the appropriate controls based on different risk scenarios. Discover how to implement these controls as service control policies, identity- and resource-based policies, and Amazon Virtual Private Cloud (Amazon VPC) endpoint policies.

Network and Infrastructure Security

Build a Zero Trust architecture for service-to-service workloads on AWS

In this workshop, get hands-on experience implementing a Zero Trust architecture for service-to-service workloads on AWS. Learn how to use services such as Amazon API Gateway and Virtual Private Cloud (Amazon VPC) endpoints to integrate network and identity controls while using Amazon GuardDuty, Lambda, and Amazon DynamoDB to take advantage of native service controls. Learn how these services allow you to authorize specific flows between components to reduce lateral network mobility risk and improve the overall security posture of your workload.

Securing deployment of third-party ML models

Enterprise users adopting machine learning (ML) on AWS often look for prescriptive guidance on implementing security best practices, establishing governance, securing their ML models, and meeting compliance standards. Building a repeatable solution provides users with standardization and governance over what gets provisioned in their AWS account. In this workshop, learn steps you can take to secure third-party ML model deployments. We provide cloud infrastructure-as-code templates to automate the setup of a hardened Amazon SageMaker environment. These templates include private networking, VPC endpoints, end-to-end encryption, logging and monitoring, and enhanced governance and access controls through AWS Service Catalog.

Building Prowler into a QuickSight-powered AWS security dashboard

In this workshop, get hands-on experience with Prowler, AWS Security Hub, and Amazon QuickSight by building a custom security dashboard for the AWS environment. Using a multi-account deployment of Prowler integrated into Security Hub, learn to identify and analyze Prowler findings and integrate QuickSight to visualize the information. Discover how to get the most from QuickSight and Prowler with automatically created datasets.

Threat Detection and Incident Response

Integration, prioritization, and response with AWS Security Hub

This workshop is designed to get you familiar with AWS Security Hub, so you can better understand how to use it in your own AWS environment. This workshop has two sections. The first section demonstrates the features and functions of AWS Security Hub. The second section shows you how to use AWS Security Hub to import findings from different data sources, analyze findings so you can prioritize response work, and implement responses to findings to help improve your security posture.

Building an AWS incident response plan using Jupyter notebooks

This workshop guides you through building an incident response plan for your AWS environment using Jupyter notebooks. Walk through an easy-to-follow sample incident, using building blocks as a ready-to-use playbook in a Jupyter notebook. Then, follow simple steps to add additional programmatic and documented steps to your incident response plan.

Scaling threat detection and response on AWS

In this hands-on workshop, learn about several AWS services involved in threat detection and response as you walk through real-world threat scenarios. Learn about the threat detection capabilities of Amazon GuardDuty, Amazon Macie, and AWS Security Hub and the available response options. For each hands-on scenario, review methods to detect and respond to threats using the following services: AWS CloudTrail, Virtual Private Cloud (Amazon VPC) Flow Logs, Amazon CloudWatch Events, AWS Lambda, Amazon Inspector, Amazon GuardDuty, and AWS Security Hub.

Building incident response playbooks for AWS

In this workshop, learn how to develop incident response playbooks. Explore the incident response lifecycle, including preparation, detection and analysis, containment, eradication and recovery, and post-incident activity. To get the most out of this workshop, you should have advanced experience with AWS services and responsibilities aligned with incident response frameworks such as NIST SP 800-61 R2.

This list is representative of the security workshops created in 2021 to help customers on their journey in AWS. If you’d like to find more workshops, please go to AWS Workshops and select Security in the top navigation bar, or you can also check out AWS Security Workshops for a subset of workshops curated by AWS Security Specialists. We hope you enjoy these workshops!

 
If you have feedback about this post, submit comments in the Comments section below.

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Author

Temi Adebambo

Temi leads the Security and Network Solutions Architecture team at AWS. His team is focused on working with customers on cloud migration and modernization, cybersecurity strategy, architecture best practices, and innovation in the cloud. Before AWS, he spent over 14 years as a consultant, advising CISOs and security leaders.

People Are Increasingly Choosing Private Web Search

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2022/01/people-are-increasingly-choosing-private-web-search.html

DuckDuckGo has had a banner year:

And yet, DuckDuckGo. The privacy-oriented search engine netted more than 35 billion search queries in 2021, a 46.4% jump over 2020 (23.6 billion). That’s big. Even so, the company, which bills itself as the “Internet privacy company,” offering a search engine and other products designed to “empower you to seamlessly take control of your personal information online without any tradeoffs,” remains a rounding error compared to Google in search.

I use it. It’s not as a good a search engine as Google. Or, at least, Google often gets me what I want faster than DuckDuckGo does. To solve that, I use use the feature that allows me to use Google’s search engine through DuckDuckGo: prepend “!Google” to searches. Basically, DuckDuckGo launders my search.

EDITED TO ADD (1/12): I was wrong. DuckDuckGo does not provide privacy protections when searching using Google.

Apple AirTags Are Being Used to Track People and Cars

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2021/12/apple-airtags-are-being-used-to-track-people-and-cars.html

This development suprises no one who has been paying attention:

Researchers now believe AirTags, which are equipped with Bluetooth technology, could be revealing a more widespread problem of tech-enabled tracking. They emit a digital signal that can be detected by devices running Apple’s mobile operating system. Those devices then report where an AirTag has last been seen. Unlike similar tracking products from competitors such as Tile, Apple added features to prevent abuse, including notifications like the one Ms. Estrada received and automatic beeping. (Tile plans to release a feature to prevent the tracking of people next year, a spokeswoman for that company said.)

[…]

A person who doesn’t own an iPhone might have a harder time detecting an unwanted AirTag. AirTags aren’t compatible with Android smartphones. Earlier this month, Apple released an Android app that can scan for AirTags — but you have to be vigilant enough to download it and proactively use it.

Apple declined to say if it was working with Google on technology that would allow Android phones to automatically detect its trackers.

People who said they have been tracked have called Apple’s safeguards insufficient. Ms. Estrada said she was notified four hours after her phone first noticed the rogue gadget. Others said it took days before they were made aware of an unknown AirTag. According to Apple, the timing of the alerts can vary depending on the iPhone’s operating system and location settings.

Updates to Cloudflare Security and Privacy Certifications and Reports

Post Syndicated from Ling Wu original https://blog.cloudflare.com/updates-to-cloudflare-security-and-privacy-certifications-and-reports/

Updates to Cloudflare Security and Privacy Certifications and Reports

Updates to Cloudflare Security and Privacy Certifications and Reports

Cloudflare’s products and services are protecting more customers than ever with significant expansion over the past year. Earlier this week, we launched Cloudflare Security Center so customers can map their attack surface, review potential security risks and threats to their organization, and have generally fast tracked many offerings to meet the needs of customers.

This rapid expansion has meant ensuring our security, privacy, and risk posture grew accordingly. Customer confidence in our ability to handle their sensitive information in an ever-changing regulatory landscape has to be as solid as our offerings, so we have expanded the scope of our previously-existing compliance validations; not only that, we’ve also managed to obtain a couple of new ones.

What’s New

We’ve had a busy year and focused on our commitment to privacy as well as complying to one of the most rigorous security standards in the industry. We are excited about the following achievements in 2021:

Updates to Cloudflare Security and Privacy Certifications and Reports

FedRAMP In Process – Cloudflare hit a major milestone by being listed on the FedRAMP Marketplace as ‘In Process’ for receiving an agency authorization at a moderate baseline. Once an Authorization to Operate (ATO) is granted, it will allow agencies and other cloud service providers to leverage our product and services in a public sector capacity.

Updates to Cloudflare Security and Privacy Certifications and Reports

ISO 27701:2019 (International Standards Organization) – Cloudflare is one of the first companies in the industry to achieve ISO 27701 certification as both a data processor and controller. The certification provides assurance to our customers that we have a formal privacy program that is aligned to GDPR.

Updates to Cloudflare Security and Privacy Certifications and Reports

Self-Serve Compliance Documentation – Pro, Business, and Enterprise customers now have the ability to obtain a copy of Cloudflare’s certifications, reports, and overview through the Cloudflare Dashboard.

Security Certifications & Reports

Cloudflare understands the importance of maintaining compliance to industry standards, certifications, and reports. Our customers rely on the certifications we have to ensure secure and private handling of their data. Each year, the security team expands the scope of these validations to ensure that all of our applicable products and services are included.  Cloudflare has met the requirements of the following standards:

Updates to Cloudflare Security and Privacy Certifications and Reports

SOC-2 Type II / SOC 3 (Service Organizations Controls) – Cloudflare maintains SOC reports that include the security, confidentiality, and availability trust principles. The SOC-2 report provides assurance that our products and underlying infrastructure are secure and highly available while protecting the confidentiality of our customer’s data. We engage with our third-party assessors on an annual basis, and the report provided to our customers covers a period of one full year.

Updates to Cloudflare Security and Privacy Certifications and Reports

ISO 27001:2013 (International Standards Organization) – Cloudflare’s ISO certification covers our entire platform. Customers can be assured that Cloudflare has a formal information security management program that adheres to a globally recognized standard.

Updates to Cloudflare Security and Privacy Certifications and Reports

PCI Data Security Standard (DSS) – Cloudflare engages with a QSA (Qualified Security Assessor) on an annual basis to evaluate us as a Level 1 Merchant and a Service Provider. This way, we can assure our customers that we meet the requirements to transmit their payment data securely. As a service provider, our customers can trust Cloudflare’s products to meet requirements of the DSS and transmit cardholder data securely through our services.

Updates to Cloudflare Security and Privacy Certifications and Reports

HIPAA/HITECH Act (Health Insurance Portability and Accountability Act/Health Information Technology for Economic and Clinical Health – Covered healthcare entities that are leveraging our enterprise version of our security products to protect their application layer can be assured that Cloudflare can sign Business Associates Agreements (BAA).

Updates to Cloudflare Security and Privacy Certifications and Reports

1.1.1.1 Public DNS Resolver Privacy Examination – Cloudflare conducted a first-of-its-kind privacy examination by a leading accounting firm to determine whether the 1.1.1.1 resolver was effectively configured to meet Cloudflare’s privacy commitments. A public summary of the assessment can be found here.

What’s on our Roadmap?

As a global company, Cloudflare partners with industry experts and regional leaders around the world to determine the best ways to build customer trust. Our infoshare events with existing customers and participation in standards organizations guide our methods to continuously improve the security and privacy posture of our products and services. Part of that improvement is obtaining additional third party validations. At this time, we are evaluating ISO 27018 to give customers additional assurance that we meet industry standards for handling personal data in our cloud platform. We will continue to move forward in our FedRAMP journey. And of course, we are continuously evaluating a range of other region-specific certifications. For the latest information about our certifications and reports, please visit our trust hub.

If you are an existing customer and want to give us feedback about a validation, please contact your Account Executive and let them know! We will continue to pursue validations that support our customers’ needs and make the internet safer and more secure.

Privacy video: Innovating securely

Post Syndicated from Chad Woolf original https://aws.amazon.com/blogs/security/privacy-video-innovating-securely/

I’m pleased to share a video of a conversation about privacy I had with my colleague Laura Dawson, the North American Lead at the AWS Institute. Privacy is becoming more of a strategic issue for our customers, similar to how security is today. We discussed how, while the two topics are similar in some ways, they also have important differences. We also talked about the importance of building a strong privacy program, and how AWS helps customers safeguard privacy while still taking advantage of digital modernization opportunities.

The differences between security and privacy aren’t fully understood in some industries. Security principles are better known in the industry – security involves considering the confidentiality, integrity, and availability of information. It’s about keeping unauthorized parties away from your data, and about making sure access to your systems and data is appropriate. Similarly, privacy is about control of data through its entire lifecycle, specifically personal identifiable information (PII). That includes the collection, use, transmission, and deletion of that data. Properly managing the privacy of PII is like security when you consider the “access control” aspect, but privacy is about making sure you always have granular control of what is happening to that PII from formation/gathering through to deletion.

Unlike security, which is now commonly recognized as a core business function, privacy practices and principles are still in the early stages of being widely accepted. This is why AWS advocates for organizations to follow the principles of Privacy by Design, to ensure that privacy processes and controls are baked into everything you do.

I also discussed with Laura some of the privacy trends I see happening in the tech industry right now, such as homomorphic encryption, anonymization, and PII discovery tools. The privacy challenges organizations face today, however, aren’t just technology challenges; they’re also business challenges, of how to get value from the data you control, in a way that meets privacy best practices and accounts for your customers’ interests.

For more about these and other privacy topics, check out the video of my conversation with Laura. To learn more about privacy at AWS, check out the Data Privacy Center and Data Protection at AWS.

Author

Chad Woolf

Chad joined Amazon in 2010 and built the AWS compliance functions from the ground up, including audit and certifications, privacy, contract compliance, control automation engineering and security process monitoring. Chad’s work also includes enabling public sector and regulated industry adoption of the AWS cloud and leads the AWS trade and product compliance team.

New German Government is Pro-Encryption and Anti-Backdoors

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2021/12/new-german-government-is-pro-encryption-and-anti-backdoors.html

I hope this is true:

According to Jens Zimmermann, the German coalition negotiations had made it “quite clear” that the incoming government of the Social Democrats (SPD), the Greens and the business-friendly liberal FDP would reject “the weakening of encryption, which is being attempted under the guise of the fight against child abuse” by the coalition partners.

Such regulations, which are already enshrined in the interim solution of the ePrivacy Regulation, for example, “diametrically contradict the character of the coalition agreement” because secure end-to-end encryption is guaranteed there, Zimmermann said.

Introducing backdoors would undermine this goal of the coalition agreement, he added.

I have written about this.

Introducing the Customer Metadata Boundary

Post Syndicated from Jon Levine original https://blog.cloudflare.com/introducing-the-customer-metadata-boundary/

Introducing the Customer Metadata Boundary

Introducing the Customer Metadata Boundary

Data localisation has gotten a lot of attention in recent years because a number of countries see it as a way of controlling or protecting their citizens’ data. Countries such as Australia, China, India, Brazil, and South Korea have or are currently considering regulations that assert legal sovereignty over their citizens’ personal data in some fashion — health care data must be stored locally; public institutions may only contract with local service providers, etc.

In the EU, the recent “Schrems II” decision resulted in additional requirements for companies that transfer personal data outside the EU. And a number of highly regulated industries require that specific types of personal data stay within the EU’s borders.

Cloudflare is committed to helping our customers keep personal data in the EU. Last year, we introduced the Data Localisation Suite, which gives customers control over where their data is inspected and stored.

Today, we’re excited to introduce the Customer Metadata Boundary, which expands the Data Localisation Suite to ensure that a customer’s end user traffic metadata stays in the EU.

Metadata: a primer

“Metadata” can be a scary term, but it’s a simple concept — it just means “data about data.” In other words, it’s a description of activity that happened on our network. Every service on the Internet collects metadata in some form, and it’s vital to user safety and network availability.

At Cloudflare, we collect metadata about the usage of our products for several purposes:

  • Serving analytics via our dashboards and APIs
  • Sharing logs with customers
  • Stopping security threats such as bot or DDoS attacks
  • Improving the performance of our network
  • Maintaining the reliability and resiliency of our network

What does that collection look like in practice at Cloudflare? Our network consists of dozens of services: our Firewall, Cache, DNS Resolver, DDoS protection systems, Workers runtime, and more. Each service emits structured log messages, which contain fields like timestamps, URLs, usage of Cloudflare features, and the identifier of the customer’s account and zone.

These messages do not contain the contents of customer traffic, and so they do not contain things like usernames, passwords, personal information, and other private details of customers’ end users. However, these logs may contain end-user IP addresses, which is considered personal data in the EU.

Data Localisation in the EU

The EU’s General Data Protection Regulation, or GDPR, is one of the world’s most comprehensive (and well known) data privacy laws. The GDPR does not, however, insist that personal data must stay in Europe. Instead, it provides a number of legal mechanisms to ensure that GDPR-level protections are available for EU personal data if it is transferred outside the EU to a third country like the United States. Data transfers from the EU to the US were, until recently, permitted under an agreement called the EU-U.S. Privacy Shield Framework.

Shortly after the GDPR went into effect, a privacy activist named Max Schrems filed suit against Facebook for their data collection practices. In July 2020, the Court of Justice of the EU issued the “Schrems II” ruling — which, among other things, invalidated the Privacy Shield framework. However, the court upheld other valid transfer mechanisms that ensure EU personal data won’t be accessed by U.S. government authorities in a way that violates the GDPR.

Since the Schrems II decision, many customers have asked us how we’re protecting EU citizens’ data. Fortunately, Cloudflare has had data protection safeguards in place since well before the Schrems II case, such as our industry-leading commitments on government data requests. In response to Schrems II in particular, we updated our customer Data Processing Addendum (DPA). We incorporated the latest Standard Contractual Clauses, which are legal agreements approved by the EU Commission that enable data transfer. We also added additional safeguards as outlined in the EDPB’s June 2021 Recommendations on Supplementary Measures. Finally, Cloudflare’s services are certified under the ISO 27701 standard, which maps to the GDPR’s requirements.

In light of these measures, we believe that our EU customers can use Cloudflare’s services in a manner consistent with GDPR and the Schrems II decision. Still, we recognize that many of our customers want their EU personal data to stay in the EU. For example, some of our customers in industries like healthcare, law, and finance may have additional requirements.  For that reason, we have developed an optional suite of services to address those requirements. We call this our Data Localisation Suite.

How the Data Localisation Suite helps today

Data Localisation is challenging for customers because of the volume and variety of data they handle. When it comes to their Cloudflare traffic, we’ve found that customers are primarily concerned about three areas:

  1. How do I ensure my encryption keys stay in the EU?
  2. How can I ensure that services like caching and WAF only run in the EU?
  3. How can ensure that metadata is never transferred outside the EU?

To address the first concern, Cloudflare has long offered Keyless SSL and Geo Key Manager, which ensure that private SSL/TLS key material never leaves the EU. Keyless SSL ensures that Cloudflare never has possession of the private key material at all; Geo Key Manager uses Keyless SSL under the hood to ensure the keys never leave the specified region.

Last year we addressed the second concern with Regional Services, which ensures that Cloudflare will only be able to decrypt and inspect the content of HTTP traffic inside the EU. In other words, SSL connections will only be terminated in Europe, and all of our layer 7 security and performance services will only run in our EU data centers.

Today, we’re enabling customers to address the third and final concern, and keep metadata local as well.

How the Metadata Boundary Works

The Customer Metadata Boundary ensures, simply, that end user traffic metadata that can identify a customer stays in the EU. This includes all the logs and analytics that a customer sees.

How are we able to do this? All the metadata that can identify a customer flows through a single service at our edge, before being forwarded to one of our core data centers.

When the Metadata Boundary is enabled for a customer, our edge ensures that any log message that identifies that customer (that is, contains that customer’s Account ID) is not sent outside the EU. It will only be sent to our core data center in the EU, and not our core data center in the US.

Introducing the Customer Metadata Boundary

What’s next

Today our Data Localisation Suite is focused on helping our customers in the EU localise data for their inbound HTTP traffic. This includes our Cache, Firewall, DDoS protection, and Bot Management products.

We’ve heard from customers that they want data localisation for more products and more regions. This means making all of our Data Localisation Products, including Geo Key Manager and Regional Services, work globally. We’re also working on expanding the Metadata Boundary to include our Zero Trust products like Cloudflare for Teams. Stay tuned!

Someone Is Running Lots of Tor Relays

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2021/12/someone-is-running-lots-of-tor-relays.html

Since 2017, someone is running about a thousand — 10% of the total — Tor servers in an attempt to deanonymize the network:

Grouping these servers under the KAX17 umbrella, Nusenu says this threat actor has constantly added servers with no contact details to the Tor network in industrial quantities, operating servers in the realm of hundreds at any given point.

The actor’s servers are typically located in data centers spread all over the world and are typically configured as entry and middle points primarily, although KAX17 also operates a small number of exit points.

Nusenu said this is strange as most threat actors operating malicious Tor relays tend to focus on running exit points, which allows them to modify the user’s traffic. For example, a threat actor that Nusenu has been tracking as BTCMITM20 ran thousands of malicious Tor exit nodes in order to replace Bitcoin wallet addresses inside web traffic and hijack user payments.

KAX17’s focus on Tor entry and middle relays led Nusenu to believe that the group, which he described as “non-amateur level and persistent,” is trying to collect information on users connecting to the Tor network and attempting to map their routes inside it.

In research published this week and shared with The Record, Nusenu said that at one point, there was a 16% chance that a Tor user would connect to the Tor network through one of KAX17’s servers, a 35% chance they would pass through one of its middle relays, and up to 5% chance to exit through one.

Slashdot thread.

Is Microsoft Stealing People’s Bookmarks?

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2021/11/is-microsoft-stealing-peoples-bookmarks.html

I received email from two people who told me that Microsoft Edge enabled synching without warning or consent, which means that Microsoft sucked up all of their bookmarks. Of course they can turn synching off, but it’s too late.

Has this happened to anyone else, or was this user error of some sort? If this is real, can some reporter write about it?

(Not that “user error” is a good justification. Any system where making a simple mistake means that you’ve forever lost your privacy isn’t a good one. We see this same situation with sharing contact lists with apps on smartphones. Apps will repeatedly ask, and only need you to accidentally click “okay” once.)

EDITED TO ADD: It’s actually worse than I thought. Edge urges users to store passwords, ID numbers, and even passport numbers, all of which get uploaded to Microsoft by default when synch is enabled.

Using Machine Learning to Guess PINs from Video

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2021/10/using-machine-learning-to-guess-pins-from-video.html

Researchers trained a machine-learning system on videos of people typing their PINs into ATMs:

By using three tries, which is typically the maximum allowed number of attempts before the card is withheld, the researchers reconstructed the correct sequence for 5-digit PINs 30% of the time, and reached 41% for 4-digit PINs.

This works even if the person is covering the pad with their hands.

The article doesn’t contain a link to the original research. If someone knows it, please put it in the comments.

Slashdot thread.

Recovering Real Faces from Face-Generation ML System

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2021/10/recovering-real-faces-from-face-generation-ml-system.html

New paper: “This Person (Probably) Exists. Identity Membership Attacks Against GAN Generated Faces.

Abstract: Recently, generative adversarial networks (GANs) have achieved stunning realism, fooling even human observers. Indeed, the popular tongue-in-cheek website http://thispersondoesnotexist.com, taunts users with GAN generated images that seem too real to believe. On the other hand, GANs do leak information about their training data, as evidenced by membership attacks recently demonstrated in the literature. In this work, we challenge the assumption that GAN faces really are novel creations, by constructing a successful membership attack of a new kind. Unlike previous works, our attack can accurately discern samples sharing the same identity as training samples without being the same samples. We demonstrate the interest of our attack across several popular face datasets and GAN training procedures. Notably, we show that even in the presence of significant dataset diversity, an over represented person can pose a privacy concern.

News article. Slashdot post.

Coalescing Connections to Improve Network Privacy and Performance

Post Syndicated from Talha Paracha original https://blog.cloudflare.com/connection-coalescing-experiments/

Coalescing Connections to Improve Network Privacy and Performance

Coalescing Connections to Improve Network Privacy and Performance

Web pages typically have a large number of embedded subresources (e.g., JavaScript, CSS, image files, ads, beacons) that are fetched by a browser on page loads. Requests for these subresources can prompt browsers to perform further DNS lookups, TCP connections, and TLS handshakes, which can have a significant impact on how long it takes for the user to see the content and interact with the page. Further, each additional request exposes metadata (such as plaintext DNS queries, or unencrypted SNI in TLS handshake) which can have potential privacy implications for the user. With these factors in mind, we carried out a measurement study to understand how we can leverage Connection Coalescing (aka Connection Reuse) to address such concerns, and study its feasibility.

Background

The web has come a long way and initially consisted of very simple protocols. One of them was HTTP/1.0, which required browsers to make a separate connection for every subresource on the page. This design was quickly recognized as having significant performance bottlenecks and was extended with HTTP pipelining and persistent connections in HTTP/1.1 revision, which allowed HTTP requests to reuse the same TCP connection. But, yet again, this was no silver bullet: while multiple requests could share the same connection, they still had to be serialized one after the other, so a client and server could only execute a single request/response exchange at any given time for each connection. As time passed, websites became more complex in structure and dynamic in nature, and HTTP/1.1 was identified as a major bottleneck. The only way to gain concurrency at the network layer was to use multiple TCP connections to the same origin in parallel, but this meant losing most benefits of persistent connections and ended up overloading the origin servers which were unable to meet the concurrency demand.

To address these performance limitations, the SPDY protocol was introduced over a decade later. SPDY supported stream multiplexing, where requests to and responses from the server used a single interleaved TCP connection, and allowed browsers to prioritize requests for critical subresources first — that were blocking page rendering. A modified variant of SPDY was standardized by the IETF as HTTP/2 in 2012 and published as RFC 7540 in 2015.

HTTP/2 and onwards retained this new standard for connection reuse. More specifically, all subresources on the same domain were able to reuse the same TCP/TLS (or UDP/QUIC) connection without any head-of-line blocking (at least on the application layer). This resulted in a single connection for all the subresources — reducing extraneous requests on page loads — potentially speeding up some websites and applications.

Interestingly, the protocol has a lesser-known feature to also enable subresources at different hostnames to be fetched over the same connection. We studied the real-world feasibility and benefits of this technique as an effort to improve users’ experience for websites across our network.

Coalescing Connections to Improve Network Privacy and Performance
Connection Coalescing allows reusing a TLS connection across different domains

Connection Coalescing

The technique is often referred to as Connection Coalescing and, to put it simply, is a way to access resources from different hostnames that are accessible from the same web server.

There are several reasons for why a single server could handle requests for different hosts, ranging from low-cost virtual hosting to the usage of CDNs and cloud providers (including Cloudflare, that acts as a reverse proxy for approximately 25 million Internet properties). Before going into the technical conditions required to enable connection coalescing, we should take a look at some benefits such a strategy can provide.

  • Privacy. When resources at different hostnames are loaded via separate TLS connections, those connections expose metadata to ISPs and other observers via the Server Name Indicator (SNI) field about the destinations that are being contacted (i.e., in the absence of encrypted SNI). This set of exposed SNI’s can allow an on-path adversary to fingerprint traffic and possibly determine user interactions on the webpage. On the other hand, coalesced requests for more than one hostname on a single connection exposes only one destination, and helps avoid such threats.
  • Performance. Additional TLS handshakes and TCP connections can incur significant costs in terms of cpu, memory and other resources. Thus, coalescing requests to use the same connection can optimize resource utilization.
  • Resource Prioritization. Multiplexing requests on a single connection means that applications have better visibility and more direct control over how related resources are prioritized and scheduled. In the absence of coalescing, the network properties (for example, route congestion) can interfere with the intended order of delivery for resources. This reliability gained through connection coalescing opens up new optimization opportunities to improve web page load times, among other things.

However, along with all these potential benefits, connection coalescing also has some associated risk factors that need to be considered in practice. First, TCP incorporates “fair” congestion control mechanisms — if there are ten connections on the same route, each gets approximately 1/10th of the total bandwidth. So with a route congested and bandwidth restricted, a client relying on multiple connections might be better off (for example, if they have five of the ten connections, their total share of bandwidth would be half). Second, browsers will use different parallelization routines for scheduling requests on multiple connections versus the same connection — it is not immediately clear whether the former or latter would perform better. Third, multiple connections exhibit an inherent form of load balancing for TLS-termination processes. That’s because multiple requests on the same connection must be answered by the same TLS-termination process that holds the session keys (often on the same physical server). So, it is important to study connection coalescing carefully before rolling it out widely.

With this context in mind, we studied the feasibility of connection coalescing on real-world traffic. More specifically, the two questions we wanted to answer were
(a) can we empirically demonstrate and quantify the theoretical benefits of connection coalescing?, and (b) could coalescing cause unintended side effects, such as performance degradation, due to the risks highlighted above?

In order to answer these questions, we first made the observation that a large number of Cloudflare customers request subresources from cdnjs — which is also powered by Cloudflare. For context, cdnjs has public JavaScript and CSS libraries (like jQuery), and is used by more than 12% of all websites on the Internet. One popular way these websites include resources from cdnjs is by using <script src="https://cdnjs.cloudflare.com/..." ></script> HTML tags. But there are other ways as well, such as the usage of XMLHttpRequest or Fetch APIs. Regardless of the way these resources are included, browsers will need to fetch them for completely loading a website.

We then identified a list of approximately four thousand websites using Cloudflare (on the Free plan) that likely used cdnjs. We divided this list of sites into evenly-sized and randomly-picked control and experiment groups. Our plan was to enable coalescing only for the experiment group, so that subresource requests generated from their web pages for cdnjs could reuse existing connections. In this way, we were able to compare results obtained on the experiment group, with the ones for the control group, and attribute any differences observed to connection coalescing.

In order to signal browsers that the requests can be coalesced, we served cdnjs and the sites from the same IP address in a few regions around the world. This meant the same DNS responses for all the zones that were part of the study — eventually load balanced by our Anycast network. These sites also had TLS certificates that included cdnjs.

The above two conditions (same IP and compatible certificate) are required to achieve coalescing as per the HTTP/2 spec. However, the QUIC spec allows coalescing even if only the second condition is met. Major web browsers are yet to adopt the QUIC coalescing mechanism, and currently use only the HTTP/2 coalescing logic for both protocols.

Coalescing Connections to Improve Network Privacy and Performance
Requests to Experiment Group Zones and cdnjs being coalesced on the same TLS connection

Results

We started noticing evidence of real-world coalescing from the day our experiment was launched. The following graph shows that approximately 50% of requests to cdnjs from our experiment group sites are coalesced (i.e., their TLS SNI does not equal cdnjs) as compared to 0% of requests from the control group sites.

Coalescing Connections to Improve Network Privacy and Performance
Coalesced Requests to cdnjs from Control and Experimental Group Zones

In addition, we conducted active measurements using our private WebPageTest instances at the landing pages of experiment and control sites — using the two well-supported browsers: Google Chrome and Firefox. From our results, Chrome created about 78% fewer TLS connections to cdnjs for our experiment group sites, as compared to the control group. But surprisingly, Firefox created just roughly 22% fewer connections. As TLS handshakes are computationally expensive because they involve cryptographic signatures and key exchange algorithms, fewer handshakes meant less CPU cycles spent by both the client and the server.

Upon further analysis, we were able to make two observations from the data:

  • A fraction of sites that never coalesced connections with either browser appeared to load subresources with CORS enabled (i.e., <script src="https://cdnjs.cloudflare.com/..." integrity="sha512-894Y..." crossorigin="anonymous">). This is the default way cdnjs recommends inclusion of subresources, as CORS is needed for integrity checks that provide substantial mitigations against script-manipulation attacks. We do not recommend removing this attribute. Our testing also revealed that using XMLHttpRequest or Fetch APIs to load subresources disabled coalescing as well. It is unclear why browsers choose to not coalesce such connections, and we are in contact with the vendors to find out.
  • Although both Firefox and Chrome coalesced requests for cdnjs on existing connections, the reason for the discrepancy in the number of TLS connections to cdnjs (approximately 78% vs roughly 22%) is because Firefox appears to open new connections even if it does not end up using them.

After evaluating the potential benefits of coalescing, we wanted to understand if coalescing caused any unintended side effects. Hence, the final measurement we conducted was to check whether our experiments were detrimental to a website’s performance. We tracked Page Load Times (PLT) and Largest Contentful Paint (LCP) across a variety of stimulated network conditions using both Chrome and Firefox and found the results for experiment vs control group to not be statistically significant.

Coalescing Connections to Improve Network Privacy and Performance
Page load times for control and experiment group sites. Each site was loaded once, and the “fullyLoaded” metric from WebPageTest is reported

Conclusion

We consider our experimentation successful in determining the feasibility of connection coalescing and highlighting its potential benefits in terms of privacy and performance. More specifically, we observed the privacy benefits of coalescing in more than 50% of requests to cdnjs from real-world traffic. In addition, our active testing demonstrated that browsers create fewer TLS connections with coalescing enabled. Interestingly, our results also revealed that the benefits might not always occur (i.e., CORS-enabled requests, Firefox creating additional TLS connections despite coalescing). Finally, we did not find any evidence that coalescing can cause harm to real-world users’ experience on the Internet.

Some future directions we would like to explore include:

  • More aggressive connection reuse with multiple hostnames, while identifying conditions most suitable for coalescing.
  • Understanding how different connection reuse methods compare, e.g., IP-based coalescing vs. use of Origin Frames, and what effects do they have on user experience over the Internet.
  • Evaluating coalescing support among different browser vendors, and encouraging adoption of HTTP/3 QUIC based coalescing.
  • Reaping the full benefits of connection coalescing by experimenting with custom priority schemes for requests within the same connection.

Please send questions and feedback to [email protected]. We’re excited to continue this line of work in our effort to help build a better Internet! For those interested in joining our team please visit our Careers Page.

Handshake Encryption: Endgame (an ECH update)

Post Syndicated from Christopher Wood original https://blog.cloudflare.com/handshake-encryption-endgame-an-ech-update/

Handshake Encryption: Endgame (an ECH update)

Handshake Encryption: Endgame (an ECH update)

Privacy and security are fundamental to Cloudflare, and we believe in and champion the use of cryptography to help provide these fundamentals for customers, end-users, and the Internet at large. In the past, we helped specify, implement, and ship TLS 1.3, the latest version of the transport security protocol underlying the web, to all of our users. TLS 1.3 vastly improved upon prior versions of the protocol with respect to security, privacy, and performance: simpler cryptographic algorithms, more handshake encryption, and fewer round trips are just a few of the many great features of this protocol.

TLS 1.3 was a tremendous improvement over TLS 1.2, but there is still room for improvement. Sensitive metadata relating to application or user intent is still visible in plaintext on the wire. In particular, all client parameters, including the name of the target server the client is connecting to, are visible in plaintext. For obvious reasons, this is problematic from a privacy perspective: Even if your application traffic to crypto.cloudflare.com is encrypted, the fact you’re visiting crypto.cloudflare.com can be quite revealing.

And so, in collaboration with other participants in the standardization community and members of industry, we embarked towards a solution for encrypting all sensitive TLS metadata in transit. The result: TLS Encrypted ClientHello (ECH), an extension to protect this sensitive metadata during connection establishment.

Last year, we described the current status of this standard and its relation to the TLS 1.3 standardization effort, as well as ECH’s predecessor, Encrypted SNI (ESNI). The protocol has come a long way since then, but when will we know when it’s ready? There are many ways by which one can measure a protocol. Is it implementable? Is it easy to enable? Does it seamlessly integrate with existing protocols or applications? In order to assess these questions and see if the Internet is ready for ECH, the community needs deployment experience. Hence, for the past year, we’ve been focused on making the protocol stable, interoperable, and, ultimately, deployable. And today, we’re pleased to announce that we’ve begun our initial deployment of TLS ECH.

What does ECH mean for connection security and privacy on the network? How does it relate to similar technologies and concepts such as domain fronting? In this post, we’ll dig into ECH details and describe what this protocol does to move the needle to help build a better Internet.

Connection privacy

For most Internet users, connections are made to perform some type of task, such as loading a web page, sending a message to a friend, purchasing some items online, or accessing bank account information. Each of these connections reveals some limited information about user behavior. For example, a connection to a messaging platform reveals that one might be trying to send or receive a message. Similarly, a connection to a bank or financial institution reveals when the user typically makes financial transactions. Individually, this metadata might seem harmless. But consider what happens when it accumulates: does the set of websites you visit on a regular basis uniquely identify you as a user? The safe answer is: yes.

This type of metadata is privacy-sensitive, and ultimately something that should only be known by two entities: the user who initiates the connection, and the service which accepts the connection. However, the reality today is that this metadata is known to more than those two entities.

Making this information private is no easy feat. The nature or intent of a connection, i.e., the name of the service such as crypto.cloudflare.com, is revealed in multiple places during the course of connection establishment: during DNS resolution, wherein clients map service names to IP addresses; and during connection establishment, wherein clients indicate the service name to the target server. (Note: there are other small leaks, though DNS and TLS are the primary problems on the Internet today.)

As is common in recent years, the solution to this problem is encryption. DNS-over-HTTPS (DoH) is a protocol for encrypting DNS queries and responses to hide this information from onpath observers. Encrypted Client Hello (ECH) is the complementary protocol for TLS.

The TLS handshake begins when the client sends a ClientHello message to the server over a TCP connection (or, in the context of QUIC, over UDP) with relevant parameters, including those that are sensitive. The server responds with a ServerHello, encrypted parameters, and all that’s needed to finish the handshake.

Handshake Encryption: Endgame (an ECH update)

The goal of ECH is as simple as its name suggests: to encrypt the ClientHello so that privacy-sensitive parameters, such as the service name, are unintelligible to anyone listening on the network. The client encrypts this message using a public key it learns by making a DNS query for a special record known as the HTTPS resource record. This record advertises the server’s various TLS and HTTPS capabilities, including ECH support. The server decrypts the encrypted ClientHello using the corresponding secret key.

Conceptually, DoH and ECH are somewhat similar. With DoH, clients establish an encrypted connection (HTTPS) to a DNS recursive resolver such as 1.1.1.1 and, within that connection, perform DNS transactions.

Handshake Encryption: Endgame (an ECH update)

With ECH, clients establish an encrypted connection to a TLS-terminating server such as crypto.cloudflare.com, and within that connection, request resources for an authorized domain such as cloudflareresearch.com.

Handshake Encryption: Endgame (an ECH update)

There is one very important difference between DoH and ECH that is worth highlighting. Whereas a DoH recursive resolver is specifically designed to allow queries for any domain, a TLS server is configured to allow connections for a select set of authorized domains. Typically, the set of authorized domains for a TLS server are those which appear on its certificate, as these constitute the set of names for which the server is authorized to terminate a connection.

Basically, this means the DNS resolver is open, whereas the ECH client-facing server is closed. And this closed set of authorized domains is informally referred to as the anonymity set. (This will become important later on in this post.) Moreover, the anonymity set is assumed to be public information. Anyone can query DNS to discover what domains map to the same client-facing server.

Why is this distinction important? It means that one cannot use ECH for the purposes of connecting to an authorized domain and then interacting with a different domain, a practice commonly referred to as domain fronting. When a client connects to a server using an authorized domain but then tries to interact with a different domain within that connection, e.g., by sending HTTP requests for an origin that does not match the domain of the connection, the request will fail.

From a high level, encrypting names in DNS and TLS may seem like a simple feat. However, as we’ll show, ECH demands a different look at security and an updated threat model.

A changing threat model and design confidence

The typical threat model for TLS is known as the Dolev-Yao model, in which an active network attacker can read, write, and delete packets from the network. This attacker’s goal is to derive the shared session key. There has been a tremendous amount of research analyzing the security of TLS to gain confidence that the protocol achieves this goal.

The threat model for ECH is somewhat stronger than considered in previous work. Not only should it be hard to derive the session key, it should also be hard for the attacker to determine the identity of the server from a known anonymity set. That is, ideally, it should have no more advantage in identifying the server than if it simply guessed from the set of servers in the anonymity set. And recall that the attacker is free to read, write, and modify any packet as part of the TLS connection. This means, for example, that an attacker can replay a ClientHello and observe the server’s response. It can also extract pieces of the ClientHello — including the ECH extension — and use them in its own modified ClientHello.

Handshake Encryption: Endgame (an ECH update)

The design of ECH ensures that this sort of attack is virtually impossible by ensuring the server certificate can only be decrypted by either the client or client-facing server.

Something else an attacker might try is masquerade as the server and actively interfere with the client to observe its behavior. If the client reacted differently based on whether the server-provided certificate was correct, this would allow the attacker to test whether a given connection using ECH was for a particular name.

Handshake Encryption: Endgame (an ECH update)

ECH also defends against this attack by ensuring that an attacker without access to the private ECH key material cannot actively inject anything into the connection.

The attacker can also be entirely passive and try to infer encrypted information from other visible metadata, such as packet sizes and timing. (Indeed, traffic analysis is an open problem for ECH and in general for TLS and related protocols.) Passive attackers simply sit and listen to TLS connections, and use what they see and, importantly, what they know to make determinations about the connection contents. For example, if a passive attacker knows that the name of the client-facing server is crypto.cloudflare.com, and it sees a ClientHello with ECH to crypto.cloudflare.com, it can conclude, with reasonable certainty, that the connection is to some domain in the anonymity set of crypto.cloudflare.com.

The number of potential attack vectors is astonishing, and something that the TLS working group has tripped over in prior iterations of the ECH design. Before any sort of real world deployment and experiment, we needed confidence in the design of this protocol. To that end, we are working closely with external researchers on a formal analysis of the ECH design which captures the following security goals:

  1. Use of ECH does not weaken the security properties of TLS without ECH.
  2. TLS connection establishment to a host in the client-facing server’s anonymity set is indistinguishable from a connection to any other host in that anonymity set.

We’ll write more about the model and analysis when they’re ready. Stay tuned!

There are plenty of other subtle security properties we desire for ECH, and some of these drill right into the most important question for a privacy-enhancing technology: Is this deployable?

Focusing on deployability

With confidence in the security and privacy properties of the protocol, we then turned our attention towards deployability. In the past, significant protocol changes to fundamental Internet protocols such as TCP or TLS have been complicated by some form of benign interference. Network software, like any software, is prone to bugs, and sometimes these bugs manifest in ways that we only detect when there’s a change elsewhere in the protocol. For example, TLS 1.3 unveiled middlebox ossification bugs that ultimately led to the middlebox compatibility mode for TLS 1.3.

While itself just an extension, the risk of ECH exposing (or introducing!) similar bugs is real. To combat this problem, ECH supports a variant of GREASE whose goal is to ensure that all ECH-capable clients produce syntactically equivalent ClientHello messages. In particular, if a client supports ECH but does not have the corresponding ECH configuration, it uses GREASE. Otherwise, it produces a ClientHello with real ECH support. In both cases, the syntax of the ClientHello messages is equivalent.

This hopefully avoids network bugs that would otherwise trigger upon real or fake ECH. Or, in other words, it helps ensure that all ECH-capable client connections are treated similarly in the presence of benign network bugs or otherwise passive attackers. Interestingly, active attackers can easily distinguish — with some probability — between real or fake ECH. Using GREASE, the ClientHello carries an ECH extension, though its contents are effectively randomized, whereas a real ClientHello using ECH has information that will match what is contained in DNS. This means an active attacker can simply compare the ClientHello against what’s in the DNS. Indeed, anyone can query DNS and use it to determine if a ClientHello is real or fake:

$ dig +short crypto.cloudflare.com TYPE65
\# 134 0001000001000302683200040008A29F874FA29F884F000500480046 FE0D0042D500200020E3541EC94A36DCBF823454BA591D815C240815 77FD00CAC9DC16C884DF80565F0004000100010013636C6F7564666C 6172652D65736E692E636F6D00000006002026064700000700000000 0000A29F874F260647000007000000000000A29F884F

Despite this obvious distinguisher, the end result isn’t that interesting. If a server is capable of ECH and a client is capable of ECH, then the connection most likely used ECH, and whether clients and servers are capable of ECH is assumed public information. Thus, GREASE is primarily intended to ease deployment against benign network bugs and otherwise passive attackers.

Note, importantly, that GREASE (or fake) ECH ClientHello messages are semantically different from real ECH ClientHello messages. This presents a real problem for networks such as enterprise settings or school environments that otherwise use plaintext TLS information for the purposes of implementing various features like filtering or parental controls. (Encrypted DNS protocols like DoH also encountered similar obstacles in their deployment.) Fundamentally, this problem reduces to the following: How can networks securely disable features like DoH and ECH? Fortunately, there are a number of approaches that might work, with the more promising one centered around DNS discovery. In particular, if clients could securely discover encrypted recursive resolvers that can perform filtering in lieu of it being done at the TLS layer, then TLS-layer filtering might be wholly unnecessary. (Other approaches, such as the use of canary domains to give networks an opportunity to signal that certain features are not permitted, may work, though it’s not clear if these could or would be abused to disable ECH.)

We are eager to collaborate with browser vendors, network operators, and other stakeholders to find a feasible deployment model that works well for users without ultimately stifling connection privacy for everyone else.

Next steps

ECH is rolling out for some FREE zones on our network in select geographic regions. We will continue to expand the set of zones and regions that support ECH slowly, monitoring for failures in the process. Ultimately, the goal is to work with the rest of the TLS working group and IETF towards updating the specification based on this experiment in hopes of making it safe, secure, usable, and, ultimately, deployable for the Internet.

ECH is one part of the connection privacy story. Like a leaky boat, it’s important to look for and plug all the gaps before taking on lots of passengers! Cloudflare Research is committed to these narrow technical problems and their long-term solutions. Stay tuned for more updates on this and related protocols.

The European Parliament Voted to Ban Remote Biometric Surveillance

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2021/10/the-european-parliament-voted-to-ban-remote-biometric-surveillance.html

It’s not actually banned in the EU yet — the legislative process is much more complicated than that — but it’s a step: a total ban on biometric mass surveillance.

To respect “privacy and human dignity,” MEPs said that EU lawmakers should pass a permanent ban on the automated recognition of individuals in public spaces, saying citizens should only be monitored when suspected of a crime.

The parliament has also called for a ban on the use of private facial recognition databases — such as the controversial AI system created by U.S. startup Clearview (also already in use by some police forces in Europe) — and said predictive policing based on behavioural data should also be outlawed.

MEPs also want to ban social scoring systems which seek to rate the trustworthiness of citizens based on their behaviour or personality.