Tag Archives: encryption

Your new free online training courses for the autumn term

Post Syndicated from Dan Fisher original https://www.raspberrypi.org/blog/free-online-training-courses-autumn-19/

Over the autumn term, we’ll be launching three brand-new, free online courses on the FutureLearn platform. Wherever you are in the world, you can learn with us for free!

Three people looking facing forward

The course presenters are Pi Towers residents Mark, Janina, and Eirini

Design and Prototype Embedded Computer Systems

The first new course is Design and Prototype Embedded Computer Systems, which will start on 28 October. In this course, you will discover the product design life cycle as you design your own embedded system!

A diagram illustrating the iterative design life cycle with four stages: Analyse, design, build, test

You’ll investigate how the purpose of the system affects the design of the system, from choosing its components to the final product, and you’ll find out more about the design of an algorithm. You will also explore how embedded systems are used in the world around us. Book your place today!

Programming 103: Saving and Structuring Data

What else would you expect us to call the sequel to Programming 101 and Programming 102? That’s right — we’ve made Programming 103: Saving and Structuring Data! The course will begin on 4 November, and you can reserve your place now.

Illustration of a robot reading a book called 'human 2 binary phrase book'

Programming 103 explores how to use data across multiple runs of your program. You’ll learn how to save text and binary files, and how structuring data is necessary for programs to “understand” the data that they load. You’ll look at common types of structured files such as CSV and JSON files, as well as how you can connect to a SQL database to use it in your Python programs.

Introduction to Encryption and Cryptography

The third course, Introduction to Encryption and Cryptography, is currently in development, and therefore coming soon. In this course, you’ll learn what encryption is and how it was used in the past, and you’ll use the Caesar and Vigenère ciphers.

The Caesar cipher is a type of substitution cipher

You’ll also look at modern encryption and investigate both symmetric and asymmetric encryption schemes. The course also shows you the future of encryption, and it includes several practical encryption activities, which can be used in the classroom too.

National Centre for Computing Education

If you’re a secondary school teacher in England, note that all of the above courses count towards your Computer Science Accelerator Programme certificate.

Group shot of the first NCCE GCSE accelerator graduates

The very first group of teachers who earned Computer Science Accelerator Programme certificates: they got to celebrate their graduation at Google HQ in London.

What’s been your favourite online course this year? Tell us about it in the comments.

The post Your new free online training courses for the autumn term appeared first on Raspberry Pi.

Crown Sterling Claims to Factor RSA Keylengths First Factored Twenty Years Ago

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2019/09/crown_sterling_.html

Earlier this month, I made fun of a company called Crown Sterling, for…for…for being a company that deserves being made fun of.

This morning, the company announced that they “decrypted two 256-bit asymmetric public keys in approximately 50 seconds from a standard laptop computer.” Really. They did. This keylength is so small it has never been considered secure. It was too small to be part of the RSA Factoring Challenge when it was introduced in 1991. In 1977, when Ron Rivest, Adi Shamir, and Len Adelman first described RSA, they included a challenge with a 426-bit key. (It was factored in 1994.)

The press release goes on: “Crown Sterling also announced the consistent decryption of 512-bit asymmetric public key in as little as five hours also using standard computing.” They didn’t demonstrate it, but if they’re right they’ve matched a factoring record set in 1999. Five hours is significantly less than the 5.2 months it took in 1999, but slower than would be expected if Crown Sterling just used the 1999 techniques with modern CPUs and networks.

Is anyone taking this company seriously anymore? I honestly wouldn’t be surprised if this was a hoax press release. It’s not currently on the company’s website. (And, if it is a hoax, I apologize to Crown Sterling. I’ll post a retraction as soon as I hear from you.)

EDITED TO ADD: First, the press release is real. And second, I forgot to include the quote from CEO Robert Grant: “Today’s decryptions demonstrate the vulnerabilities associated with the current encryption paradigm. We have clearly demonstrated the problem which also extends to larger keys.”

People, this isn’t hard. Find an RSA Factoring Challenge number that hasn’t been factored yet and factor it. Once you do, the entire world will take you seriously. Until you do, no one will. And, bonus, you won’t have to reveal your super-secret world-destabilizing cryptanalytic techniques.

EDITED TO ADD (9/21): Others are laughing at this, too.

EDITED TO ADD (9/24): More commentary.

How Cloudflare and Wall Street Are Helping Encrypt the Internet Today

Post Syndicated from Nick Sullivan original https://blog.cloudflare.com/how-cloudflare-and-wall-street-are-helping-encrypt-the-internet-today/

How Cloudflare and Wall Street Are Helping Encrypt the Internet Today

How Cloudflare and Wall Street Are Helping Encrypt the Internet Today

Today has been a big day for Cloudflare, as we became a public company on the New York Stock Exchange (NYSE: NET). To mark the occasion, we decided to bring our favorite entropy machines to the floor of the NYSE. Footage of these lava lamps is being used as an additional seed to our entropy-generation system LavaRand — bolstering Internet encryption for over 20 million Internet properties worldwide.

(This is mostly for fun. But when’s the last time you saw a lava lamp on the trading floor of the New York Stock Exchange?)

How Cloudflare and Wall Street Are Helping Encrypt the Internet Today

A little context: generating truly random numbers using computers is impossible, because code is inherently deterministic (i.e. predictable). To compensate for this, engineers draw from pools of randomness created by entropy generators, which is a fancy term for “things that are truly unpredictable”.

It turns out that lava lamps are fantastic sources of entropy, as was first shown by Silicon Graphics in the 1990s. It’s a torch we’ve been proud to carry forward: today, Cloudflare uses lava lamps to generate entropy that helps make millions of Internet properties more secure.

How Cloudflare and Wall Street Are Helping Encrypt the Internet Today

Housed in our San Francisco headquarters is a wall filled with dozens of lava lamps, undulating with mesmerizing randomness. We capture these lava lamps on video via a camera mounted across the room, and feed the resulting footage into an algorithm — called LavaRand — that amplifies the pure randomness of these lava lamps to dizzying extremes (computers can’t create seeds of pure randomness, but they can massively amplify them).

Shortly before we rang the opening bell this morning, we recorded footage of our lava lamps in operation on the trading room floor of the New York Stock Exchange, and we’re ingesting the footage into our LavaRand system. The resulting entropy is mixed with the myriad additional sources of entropy that we leverage every day, creating a cryptographically-secure source of randomness — fortified by Wall Street.

How Cloudflare and Wall Street Are Helping Encrypt the Internet Today

We recently took our enthusiasm for randomness a step further by facilitating the League of Entropy, a consortium of global organizations and individual contributors, generating verifiable randomness via a globally distributed network. As one of the founding members of the League, LavaRand (pictured above) plays a key role in empowering developers worldwide with a pool of randomness with extreme entropy and high reliability.

And today, she’s enjoying the view from the podium!


One caveat: the lava lamps we run in our San Francisco headquarters are recorded in real-time, 24/7, giving us an ongoing stream of entropy. For reasons that are understandable, the NYSE doesn’t allow for live video feeds from the exchange floor while it is in operation. But this morning they did let us record footage of the lava lamps operating shortly before the opening bell. The video was recorded and we’re ingesting it into our LavaRand system (alongside many other entropy generators, including the lava lamps back in San Francisco).

More on Law Enforcement Backdoor Demands

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2019/09/more_on_law_enf.html

The Carnegie Endowment for International Peace and Princeton University’s Center for Information Technology Policy convened an Encryption Working Group to attempt progress on the “going dark” debate. They have released their report: “Moving the Encryption Policy Conversation Forward.

The main contribution seems to be that attempts to backdoor devices like smartphones shouldn’t also backdoor communications systems:

Conclusion: There will be no single approach for requests for lawful access that can be applied to every technology or means of communication. More work is necessary, such as that initiated in this paper, to separate the debate into its component parts, examine risks and benefits in greater granularity, and seek better data to inform the debate. Based on our attempt to do this for one particular area, the working group believes that some forms of access to encrypted information, such as access to data at rest on mobile phones, should be further discussed. If we cannot have a constructive dialogue in that easiest of cases, then there is likely none to be had with respect to any of the other areas. Other forms of access to encrypted information, including encrypted data-in-motion, may not offer an achievable balance of risk vs. benefit, and as such are not worth pursuing and should not be the subject of policy changes, at least for now. We believe that to be productive, any approach must separate the issue into its component parts.

I don’t believe that backdoor access to encryption data at rest offers “an achievable balance of risk vs. benefit” either, but I agree that the two aspects should be treated independently.

EDITED TO ADD (9/12): This report does an important job moving the debate forward. It advises that policymakers break the issues into component parts. Instead of talking about restricting all encryption, it separates encrypted data at rest (storage) from encrypted data in motion (communication). It advises that policymakers pick the problems they have some chance of solving, and not demand systems that put everyone in danger. For example: no key escrow, and no use of software updates to break into devices).

Data in motion poses challenges that are not present for data at rest. For example, modern cryptographic protocols for data in motion use a separate “session key” for each message, unrelated to the private/public key pairs used to initiate communication, to preserve the message’s secrecy independent of other messages (consistent with a concept known as “forward secrecy”). While there are potential techniques for recording, escrowing, or otherwise allowing access to these session keys, by their nature, each would break forward secrecy and related concepts and would create a massive target for criminal and foreign intelligence adversaries. Any technical steps to simplify the collection or tracking of session keys, such as linking keys to other keys or storing keys after they are used, would represent a fundamental weakening of all the communications.

These are all big steps forward given who signed on to the report. Not just the usual suspects, but also Jim Baker — former general counsel of the FBI — and Chris Inglis: former deputy director of the NSA.

The Myth of Consumer-Grade Security

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2019/08/the_myth_of_con.html

The Department of Justice wants access to encrypted consumer devices but promises not to infiltrate business products or affect critical infrastructure. Yet that’s not possible, because there is no longer any difference between those categories of devices. Consumer devices are critical infrastructure. They affect national security. And it would be foolish to weaken them, even at the request of law enforcement.

In his keynote address at the International Conference on Cybersecurity, Attorney General William Barr argued that companies should weaken encryption systems to gain access to consumer devices for criminal investigations. Barr repeated a common fallacy about a difference between military-grade encryption and consumer encryption: “After all, we are not talking about protecting the nation’s nuclear launch codes. Nor are we necessarily talking about the customized encryption used by large business enterprises to protect their operations. We are talking about consumer products and services such as messaging, smart phones, e-mail, and voice and data applications.”

The thing is, that distinction between military and consumer products largely doesn’t exist. All of those “consumer products” Barr wants access to are used by government officials — heads of state, legislators, judges, military commanders and everyone else — worldwide. They’re used by election officials, police at all levels, nuclear power plant operators, CEOs and human rights activists. They’re critical to national security as well as personal security.

This wasn’t true during much of the Cold War. Before the Internet revolution, military-grade electronics were different from consumer-grade. Military contracts drove innovation in many areas, and those sectors got the cool new stuff first. That started to change in the 1980s, when consumer electronics started to become the place where innovation happened. The military responded by creating a category of military hardware called COTS: commercial off-the-shelf technology. More consumer products became approved for military applications. Today, pretty much everything that doesn’t have to be hardened for battle is COTS and is the exact same product purchased by consumers. And a lot of battle-hardened technologies are the same computer hardware and software products as the commercial items, but in sturdier packaging.

Through the mid-1990s, there was a difference between military-grade encryption and consumer-grade encryption. Laws regulated encryption as a munition and limited what could legally be exported only to key lengths that were easily breakable. That changed with the rise of Internet commerce, because the needs of commercial applications more closely mirrored the needs of the military. Today, the predominant encryption algorithm for commercial applications — Advanced Encryption Standard (AES) — is approved by the National Security Agency (NSA) to secure information up to the level of Top Secret. The Department of Defense’s classified analogs of the Internet­ — Secret Internet Protocol Router Network (SIPRNet), Joint Worldwide Intelligence Communications System (JWICS) and probably others whose names aren’t yet public — use the same Internet protocols, software, and hardware that the rest of the world does, albeit with additional physical controls. And the NSA routinely assists in securing business and consumer systems, including helping Google defend itself from Chinese hackers in 2010.

Yes, there are some military applications that are different. The US nuclear system Barr mentions is one such example — and it uses ancient computers and 8-inch floppy drives. But for pretty much everything that doesn’t see active combat, it’s modern laptops, iPhones, the same Internet everyone else uses, and the same cloud services.

This is also true for corporate applications. Corporations rarely use customized encryption to protect their operations. They also use the same types of computers, networks, and cloud services that the government and consumers use. Customized security is both more expensive because it is unique, and less secure because it’s nonstandard and untested.

During the Cold War, the NSA had the dual mission of attacking Soviet computers and communications systems and defending domestic counterparts. It was possible to do both simultaneously only because the two systems were different at every level. Today, the entire world uses Internet protocols; iPhones and Android phones; and iMessage, WhatsApp and Signal to secure their chats. Consumer-grade encryption is the same as military-grade encryption, and consumer security is the same as national security.

Barr can’t weaken consumer systems without also weakening commercial, government, and military systems. There’s one world, one network, and one answer. As a matter of policy, the nation has to decide which takes precedence: offense or defense. If security is deliberately weakened, it will be weakened for everybody. And if security is strengthened, it is strengthened for everybody. It’s time to accept the fact that these systems are too critical to society to weaken. Everyone will be more secure with stronger encryption, even if it means the bad guys get to use that encryption as well.

This essay previously appeared on Lawfare.com.

Facebook Plans on Backdooring WhatsApp

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2019/08/facebook_plans_.html

This article points out that Facebook’s planned content moderation scheme will result in an encryption backdoor into WhatsApp:

In Facebook’s vision, the actual end-to-end encryption client itself such as WhatsApp will include embedded content moderation and blacklist filtering algorithms. These algorithms will be continually updated from a central cloud service, but will run locally on the user’s device, scanning each cleartext message before it is sent and each encrypted message after it is decrypted.

The company even noted that when it detects violations it will need to quietly stream a copy of the formerly encrypted content back to its central servers to analyze further, even if the user objects, acting as true wiretapping service.

Facebook’s model entirely bypasses the encryption debate by globalizing the current practice of compromising devices by building those encryption bypasses directly into the communications clients themselves and deploying what amounts to machine-based wiretaps to billions of users at once.

Once this is in place, it’s easy for the government to demand that Facebook add another filter — one that searches for communications that they care about — and alert them when it gets triggered.

Of course alternatives like Signal will exist for those who don’t want to be subject to Facebook’s content moderation, but what happens when this filtering technology is built into operating systems?

The problem is that if Facebook’s model succeeds, it will only be a matter of time before device manufacturers and mobile operating system developers embed similar tools directly into devices themselves, making them impossible to escape. Embedding content scanning tools directly into phones would make it possible to scan all apps, including ones like Signal, effectively ending the era of encrypted communications.

I don’t think this will happen — why does AT&T care about content moderation — but it is something to watch?

EDITED TO ADD (8/2): This story is wrong. Read my correction.

Attorney General William Barr on Encryption Policy

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2019/07/attorney_genera_1.html

Yesterday, Attorney General William Barr gave a major speech on encryption policy — what is commonly known as “going dark.” Speaking at Fordham University in New York, he admitted that adding backdoors decreases security but that it is worth it.

Some hold this view dogmatically, claiming that it is technologically impossible to provide lawful access without weakening security against unlawful access. But, in the world of cybersecurity, we do not deal in absolute guarantees but in relative risks. All systems fall short of optimality and have some residual risk of vulnerability a point which the tech community acknowledges when they propose that law enforcement can satisfy its requirements by exploiting vulnerabilities in their products. The real question is whether the residual risk of vulnerability resulting from incorporating a lawful access mechanism is materially greater than those already in the unmodified product. The Department does not believe this can be demonstrated.

Moreover, even if there was, in theory, a slight risk differential, its significance should not be judged solely by the extent to which it falls short of theoretical optimality. Particularly with respect to encryption marketed to consumers, the significance of the risk should be assessed based on its practical effect on consumer cybersecurity, as well as its relation to the net risks that offering the product poses for society. After all, we are not talking about protecting the Nation’s nuclear launch codes. Nor are we necessarily talking about the customized encryption used by large business enterprises to protect their operations. We are talking about consumer products and services such as messaging, smart phones, e-mail, and voice and data applications. If one already has an effective level of security say, by way of illustration, one that protects against 99 percent of foreseeable threats is it reasonable to incur massive further costs to move slightly closer to optimality and attain a 99.5 percent level of protection? A company would not make that expenditure; nor should society. Here, some argue that, to achieve at best a slight incremental improvement in security, it is worth imposing a massive cost on society in the form of degraded safety. This is untenable. If the choice is between a world where we can achieve a 99 percent assurance against cyber threats to consumers, while still providing law enforcement 80 percent of the access it might seek; or a world, on the other hand, where we have boosted our cybersecurity to 99.5 percent but at a cost reducing law enforcements [sic] access to zero percent the choice for society is clear.

I think this is a major change in government position. Previously, the FBI, the Justice Department and so on had claimed that backdoors for law enforcement could be added without any loss of security. They maintained that technologists just need to figure out how: ­an approach we have derisively named “nerd harder.”

With this change, we can finally have a sensible policy conversation. Yes, adding a backdoor increases our collective security because it allows law enforcement to eavesdrop on the bad guys. But adding that backdoor also decreases our collective security because the bad guys can eavesdrop on everyone. This is exactly the policy debate we should be having­not the fake one about whether or not we can have both security and surveillance.

Barr makes the point that this is about “consumer cybersecurity,” and not “nuclear launch codes.” This is true, but ignores the huge amount of national security-related communications between those two poles. The same consumer communications and computing devices are used by our lawmakers, CEOs, legislators, law enforcement officers, nuclear power plant operators, election officials and so on. There’s no longer a difference between consumer tech and government tech — it’s all the same tech.

Barr also says:

Further, the burden is not as onerous as some make it out to be. I served for many years as the general counsel of a large telecommunications concern. During my tenure, we dealt with these issues and lived through the passage and implementation of CALEA the Communications Assistance for Law Enforcement Act. CALEA imposes a statutory duty on telecommunications carriers to maintain the capability to provide lawful access to communications over their facilities. Companies bear the cost of compliance but have some flexibility in how they achieve it, and the system has by and large worked. I therefore reserve a heavy dose of skepticism for those who claim that maintaining a mechanism for lawful access would impose an unreasonable burden on tech firms especially the big ones. It is absurd to think that we would preserve lawful access by mandating that physical telecommunications facilities be accessible to law enforcement for the purpose of obtaining content, while allowing tech providers to block law enforcement from obtaining that very content.

That telecommunications company was GTE­which became Verizon. Barr conveniently ignores that CALEA-enabled phone switches were used to spy on government officials in Greece in 2003 — which seems to have been an NSA operation — and on a variety of people in Italy in 2006. Moreover, in 2012 every CALEA-enabled switch sold to the Defense Department had security vulnerabilities. (I wrote about all this, and more, in 2013.)

The final thing I noticed about the speech is that is it not about iPhones and data at rest. It is about communications: ­data in transit. The “going dark” debate has bounced back and forth between those two aspects for decades. It seems to be bouncing once again.

I hope that Barr’s latest speech signals that we can finally move on from the fake security vs. privacy debate, and to the real security vs. security debate. I know where I stand on that: As computers continue to permeate every aspect of our lives, society, and critical infrastructure, it is much more important to ensure that they are secure from everybody — even at the cost of law-enforcement access — than it is to allow access at the cost of security. Barr is wrong, it kind of is like these systems are protecting nuclear launch codes.

This essay previously appeared on Lawfare.com.

EDITED TO ADD: More news articles.

EDITED TO ADD (7/28): Gen. Hayden comments.

EDITED TO ADD (7/30): Good response by Robert Graham.

Presidential Candidate Andrew Yang Has Quantum Encryption Policy

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2019/07/presidential_ca.html

At least one presidential candidate has a policy about quantum computing and encryption.

It has two basic planks. One: fund quantum-resistant encryption standards. (Note: NIST is already doing this.) Two, fund quantum computing. (Unlike many far more pressing computer security problems, the market seems to be doing this on its own quite nicely.)

Okay, so not the greatest policy — but at least one candidate has a policy. Do any of the other candidates have anything else in this area?

Yang has also talked about blockchain: “

“I believe that blockchain needs to be a big part of our future,” Yang told a crowded room at the Consensus conference in New York, where he gave a keynote address Wednesday. “If I’m in the White House, oh boy are we going to have some fun in terms of the crypto currency community.”

Okay, so that’s not so great, either. But again, I don’t think anyone else talks about this.

Note: this is not an invitation to talk more general politics. Not even an invitation to explain how good or bad Andrew Yang’s chances are. Or anyone else’s. Please.

Google Releases Basic Homomorphic Encryption Tool

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2019/07/google_releases_1.html

Google has released an open-source cryptographic tool: Private Join and Compute. From a Wired article:

Private Join and Compute uses a 1970s methodology known as “commutative encryption” to allow data in the data sets to be encrypted with multiple keys, without it mattering which order the keys are used in. This is helpful for multiparty computation, where you need to apply and later peel away multiple layers of encryption without affecting the computations performed on the encrypted data. Crucially, Private Join and Compute also uses methods first developed in the ’90s that enable a system to combine two encrypted data sets, determine what they have in common, and then perform mathematical computations directly on this encrypted, unreadable data through a technique called homomorphic encryption.

True homomorphic encryption isn’t possible, and my guess is that it will never be feasible for most applications. But limited application tricks like this have been around for decades, and sometimes they’re useful.

Boing Boing article.

Yubico Security Keys with a Crypto Flaw

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2019/07/yubico_security.html

Wow, is this an embarrassing bug:

Yubico is recalling a line of security keys used by the U.S. government due to a firmware flaw. The company issued a security advisory today that warned of an issue in YubiKey FIPS Series devices with firmware versions 4.4.2 and 4.4.4 that reduced the randomness of the cryptographic keys it generates. The security keys are used by thousands of federal employees on a daily basis, letting them securely log-on to their devices by issuing one-time passwords.

The problem in question occurs after the security key powers up. According to Yubico, a bug keeps “some predictable content” inside the device’s data buffer that could impact the randomness of the keys generated. Security keys with ECDSA signatures are in particular danger. A total of 80 of the 256 bits generated by the key remain static, meaning an attacker who gains access to several signatures could recreate the private key.

Boing Boing post.

MongoDB Offers Field Level Encryption

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

MongoDB now has the ability to encrypt data by field:

MongoDB calls the new feature Field Level Encryption. It works kind of like end-to-end encrypted messaging, which scrambles data as it moves across the internet, revealing it only to the sender and the recipient. In such a “client-side” encryption scheme, databases utilizing Field Level Encryption will not only require a system login, but will additionally require specific keys to process and decrypt specific chunks of data locally on a user’s device as needed. That means MongoDB itself and cloud providers won’t be able to access customer data, and a database’s administrators or remote managers don’t need to have access to everything either.

For regular users, not much will be visibly different. If their credentials are stolen and they aren’t using multifactor authentication, an attacker will still be able to access everything the victim could. But the new feature is meant to eliminate single points of failure. With Field Level Encryption in place, a hacker who steals an administrative username and password, or finds a software vulnerability that gives them system access, still won’t be able to use these holes to access readable data.

Germany Talking about Banning End-to-End Encryption

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

Der Spiegel is reporting that the German Ministry for Internal Affairs is planning to require all Internet message services to provide plaintext messages on demand, basically outlawing strong end-to-end encryption. Anyone not complying will be blocked, although the article doesn’t say how. (Cory Doctorow has previously explained why this would be impossible.)

The article is in German, and I would appreciate additional information from those who can speak the language.

EDITED TO ADD (6/2): Slashdot thread. This seems to be nothing more than political grandstanding: see this post from the Carnegie Endowment for International Peace.

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.

How to share encrypted AMIs across accounts to launch encrypted EC2 instances

Post Syndicated from Nishit Nagar original https://aws.amazon.com/blogs/security/how-to-share-encrypted-amis-across-accounts-to-launch-encrypted-ec2-instances/

Do you encrypt your Amazon Machine Instances (AMIs) with AWS Key Management Service (AWS KMS) customer master keys (CMKs) for regulatory or compliance reasons? Do you launch instances with encrypted root volumes? Do you create a golden AMI and distribute it to other accounts in your organization for standardizing application-specific Amazon Elastic Compute Cloud (Amazon EC2) instance launches? If so, then we have good news for you!

We’re happy to announce that you can now share AMIs encrypted with customer-managed CMKs across accounts with a single API call. Additionally, you can launch an EC2 instance directly from an encrypted AMI that has been shared with you. Previously, this was possible for unencrypted AMIs only. Extending this capability to encrypted AMIs simplifies your AMI distribution process and reduces the snapshot storage cost associated with the older method of sharing encrypted AMIs that resulted in a copy in each of your accounts.

In this post, we demonstrate how you can share an encrypted AMI between accounts and launch an encrypted, Amazon Elastic Block Store (Amazon EBS) backed EC2 instance from the shared AMI.

Prerequisites for sharing AMIs encrypted with a customer-managed CMK

Before you can begin sharing the encrypted AMI and launching an instance from it, you’ll need to set up your AWS KMS key policy and AWS Identity and Access Management (IAM) policies.

For this walkthrough, you need two AWS accounts:

  1. A source account in which you build a custom AMI and encrypt the associated EBS snapshots.
  2. A target account in which you launch instances using the shared custom AMI with encrypted snapshots.

In this example, I’ll use fictitious account IDs 111111111111 and 999999999999 for the source account and the target account, respectively. In addition, you’ll need to create an AWS KMS customer master key (CMK) in the source account in the source region. For simplicity, I’ve created an AWS KMS CMK with the alias cmkSource under account 111111111111 in us-east-1. I’ll use this cmkSource to encrypt my AMI (ami-1234578) that I’ll share with account 999999999999. As you go through this post, be sure to change the account IDs, source account, AWS KMS CMK, and AMI ID to match your own.

Create the policy setting for the source account

First, an IAM user or role in the source account needs permission to share the AMI (an EC2 ModifyImageAttribute operation). The following JSON policy document shows an example of the permissions an IAM user or role policy needs to have. In order to share ami-12345678, you’ll need to create a policy like this:


    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Action": [
                "ec2: ModifyImageAttribute",
            ],
            "Resource": [
                "arn:aws:ec2:us-east-1::image/<12345678>"
            ]
        }
 ] 
}

Second, the target account needs permission to use cmkSource for re-encrypting the snapshots. The following steps walk you through how to add the target account’s ID to the cmkSource key policy.

  1. From the IAM console, select Encryption Keys in the left pane, and then select the source account’s CMK, cmkSource, as shown in Figure 1:
     
    Figure 1: Select "cmkSource"

    Figure 1: Select “cmkSource”

  2. Look for the External Accounts subsection, type the target account ID (for example, 999999999999), and then select Add External Account.
     
    Figure 2: Enter the target account ID and then select "Add External Account"

    Figure 2: Enter the target account ID and then select “Add External Account”

Create a policy setting for the target account

Once you’ve configured the source account, you need to configure the target account. The IAM user or role in the target account needs to be able to perform the AWS KMS DescribeKey, CreateGrant, ReEncrypt* and Decrypt operations on cmkSource in order to launch an instance from a shared encrypted AMI. The following JSON policy document shows an example of these permissions:


{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Action": [
                "kms:DescribeKey",
                "kms:ReEncrypt*",
                "kms:CreateGrant",
                "kms:Decrypt"
            ],
            "Resource": [
                "arn:aws:kms:us-east-1:<111111111111>:key/<key-id of cmkSource>"
            ]                                                    
        }
    ]
}

Once you’ve completed the configuration steps in the source and target accounts, then you’re ready to share and launch encrypted AMIs. The actual sharing of the encrypted AMI is no different from sharing an unencrypted AMI. If you want to use the AWS Management Console, then follow the steps described in Sharing an AMI (Console). To use the AWS Command Line Interface (AWS CLI), follow the steps described in Sharing an AMI (AWS CLI).

Below is an example of what the CLI command to share the AMI would look like:


aws ec2 modify-image-attribute --image-id <ami-12345678> --launch-permission "Add=[{UserId=<999999999999>}]"

Launch an instance from the shared encrypted AMI

To launch an AMI that was shared with you, set the AMI ID of the shared AMI in the image-id parameter of Run-Instances API/CLI. Optionally, to re-encrypt the volumes with a custom CMK in your account, you can specify the KmsKeyId in the Block Device Mapping as follows:


    $> aws ec2 run-instances 
    --image-id ami-
    --count 1 
    --instance-type m4.large 
    --region us-east-1
    --subnet-id subnet-aec2fc86 
    --key-name 2016KeyPair 
    --security-group-ids sg-f7dbc78e subnet-id subnet-aec2fc86 
    --block-device-mappings file://mapping.json    

Where the mapping.json contains the following:


[
    {
        "DeviceName": "/dev/xvda",
        "Ebs": {
                "Encrypted": true,
                "KmsKeyId": "arn:aws:kms:us-east-1:<999999999999>:key/<abcd1234-a123-456a-a12b-a123b4cd56ef>"
        }
    },
]

While launching the instance from a shared encrypted AMI, you can specify a CMK of your choice. You may also choose cmkSource to encrypt volumes in your account. However, we recommend that you re-encrypt the volumes using a CMK in the target account. This protects you if the source CMK is compromised, or if the source account revokes permissions, which could cause you to lose access to any encrypted volumes you created using cmkSource.

Summary

In this blog post, we discussed how you can easily share encrypted AMIs across accounts to launch encrypted instances. AWS has extended the same capabilities to snapshots, allowing you to create encrypted EBS volumes from shared encrypted snapshots.

This feature is available through the AWS Management Console, AWS CLI, or AWS SDKs at no extra charge in all commercial AWS regions except China. If you have feedback about this blog post, submit comments in the Comments section below. If you have questions about this blog post, start a new thread on the Amazon EC2 forum or contact AWS Support.

Want more AWS Security how-to content, news, and feature announcements? Follow us on Twitter.

Author

Nishit Nagar

Nishit is a Senior Product Manager at AWS.

How to quickly launch encrypted EBS-backed EC2 instances from unencrypted AMIs

Post Syndicated from Nishit Nagar original https://aws.amazon.com/blogs/security/how-to-quickly-launch-encrypted-ebs-backed-ec2-instances-from-unencrypted-amis/

An Amazon Machine Image (AMI) provides the information that you need to launch an instance (a virtual server) in your AWS environment. There are a number of AMIs on the AWS Marketplace (such as Amazon Linux, Red Hat or Ubuntu) that you can use to launch an Amazon Elastic Compute Cloud (Amazon EC2) instance. When you launch an instance from these AMIs, the resulting volumes are unencrypted. However, for regulatory purposes or internal compliance reasons, you might need to launch instances with encrypted root volumes. Previously, this required you to follow a a multi-step process in which you maintained a separate, encrypted copy of the AMI in your account in order to launch instances with encrypted volumes. Now, you no longer need to maintain multiple AMI copies for encryption. To launch an encrypted Amazon Elastic Block Store (Amazon EBS) backed instance from an unencrypted AMI, you can directly specify the encryption properties in your existing workflow (such as with the RunInstances API or the Launch Instance Wizard). This simplifies the process of launching instances with encrypted volumes and reduces your associated AMI storage costs.

In this post, we demonstrate how you can start from an unencrypted AMI and launch an encrypted EBS-backed Amazon EC2 instance. We’ll show you how to do this from both the AWS Management Console, and using the RunInstances API with the AWS Command Line Interface (AWS CLI).

Launching an instance from the AWS Management Console

  1. Sign into the AWS Management Console and open the EC2 console.
  2. Select Launch instance, then follow the prompts of the launch wizard:
    1. In step 1 of the wizard, select the Amazon Machine Image (AMI) that you want to use.
    2. In step 2 of the wizard, select your instance type.
    3. In step 3, provide additional configuration details. For details about configuring your instances, see Launching an Instance.
    4. In step 4, specify your EBS volumes. The encryption properties of the volumes will be inherited from the AMI that you’ve chosen. If you’re using an unencrypted AMI, it will show up as “Not Encrypted.” From the dropdown, you can then select a customer master key (CMK) for encrypting the volume. You may select the same CMK for each volume that you want to create, or you may use a different CMK for each volume.
       
      Figure 1: Specifying your EBS volumes

      Figure 1: Specifying your EBS volumes

  3. Select Review and then Launch. Your instance will launch with an encrypted Amazon EBS volume that uses the CMK you selected. To learn more about the launch wizard, see Launching an Instance with Launch Wizard.

Launching an instance from the RunInstances API

From the RunInstances API/CLI, you can provide the kmsKeyID for encrypting the volumes that will be created from the AMI by specifying encryption in the BlockDeviceMapping (BDM) object. If you don’t specify the kmsKeyID in BDM but set the encryption flag to “true,” then AWS Managed CMK will be used for encrypting the volume.

For example, to launch an encrypted instance from an Amazon Linux AMI with an additional empty 100 GB of data volume (/dev/sdb), the API call would be as follows:


    $> aws ec2 run-instances 
    --image-id ami-009d6802948d06e52
    --count 1 
    --instance-ype m4.large 
    --region us-east-1
    --subnet-id subnet-aec2fc86 
    --key-name 2016KeyPair 
    --security-group-ids sg-f7dbc78e subnet-id subnet-aec2fc86 
    --block-device-mappings file://mapping.json    

Where the mapping.json contains the following:


[
    {
        "DeviceName": "/dev/xvda",
        "Ebs": {
                "Encrypted": true,
                "KmsKeyId": "arn:aws:kms:<us-east-1:012345678910>:key/<Example_Key_ID_12345>"
        }
    },

    {
        "DeviceName": "/dev/sdb",
        "Ebs": {
            "DeleteOnTermination": true,
            "VolumeSize": 100,
            "VolumeType": "gp2",
            "Encrypted": true,
            "KmsKeyId": "arn:aws:kms:<us-east-1:012345678910>:key/<Example_Key_ID_12345>"
        }
    }
]

You may specify different keys for different volumes. Providing a kmsKeyID without the encryption flag will result in an API error.

Conclusion

In this blog post, we demonstrated how you can quickly launch encrypted, EBS-backed instances from an unencrypted AMI in a few steps. You can also use the same process to launch EBS-backed encrypted volumes from unencrypted snapshots. This simplifies the process of launching instances with encrypted volumes and reduces your AMI storage costs.

This feature is available through the AWS Management Console, AWS CLI, or AWS SDKs at no extra charge in all commercial AWS regions except China. If you have feedback about this blog post, submit comments in the Comments section below. If you have questions about this blog post, start a new thread on the Amazon EC2 forum or contact AWS Support.

Want more AWS Security how-to content, news, and feature announcements? Follow us on Twitter.

Author

Nishit Nagar

Nishit is a Senior Product Manager at AWS.

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.

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.

G7 Comes Out in Favor of Encryption Backdoors

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2019/04/g7_comes_out_in.html

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

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

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