Attack on Old ANSI Random Number Generator

Almost 20 years ago, I wrote a paper that pointed to a potential flaw in the ANSI X9.17 RNG standard. Now, new research has found that the flaw exists in some implementations of the RNG standard. Here’s the research paper, the website — complete with cute logo — for the attack, and Matthew Green’s excellent blog post on the research….

Almost 20 years ago, I wrote a paper that pointed to a potential flaw in the ANSI X9.17 RNG standard. Now, new research has found that the flaw exists in some implementations of the RNG standard.

Here's the research paper, the website -- complete with cute logo -- for the attack, and Matthew Green's excellent blog post on the research.

from https://www.schneier.com/blog/

FBI Increases Its Anti-Encryption Rhetoric

Earlier this month, Deputy Attorney General Rod Rosenstein gave a speech warning that a world with encryption is a world without law — or something like that. The EFF’s Kurt Opsahl takes it apart pretty thoroughly. Last week, FBI Director Christopher Wray said much the same thing. This is an idea that will not die….

Earlier this month, Deputy Attorney General Rod Rosenstein gave a speech warning that a world with encryption is a world without law -- or something like that. The EFF's Kurt Opsahl takes it apart pretty thoroughly.

Last week, FBI Director Christopher Wray said much the same thing.

This is an idea that will not die.

from https://www.schneier.com/blog/

Security Flaw in Infineon Smart Cards and TPMs

A security flaw in Infineon smart cards and TPMs allows an attacker to recover private keys from the public keys. Basically, the key generation algorithm sometimes creates public keys that are vulnerable to Coppersmith’s attack: While all keys generated with the library are much weaker than they should be, it’s not currently practical to factorize all of them. For example,…

A security flaw in Infineon smart cards and TPMs allows an attacker to recover private keys from the public keys. Basically, the key generation algorithm sometimes creates public keys that are vulnerable to Coppersmith's attack:

While all keys generated with the library are much weaker than they should be, it's not currently practical to factorize all of them. For example, 3072-bit and 4096-bit keys aren't practically factorable. But oddly enough, the theoretically stronger, longer 4096-bit key is much weaker than the 3072-bit key and may fall within the reach of a practical (although costly) factorization if the researchers' method improves.

To spare time and cost, attackers can first test a public key to see if it's vulnerable to the attack. The test is inexpensive, requires less than 1 millisecond, and its creators believe it produces practically zero false positives and zero false negatives. The fingerprinting allows attackers to expend effort only on keys that are practically factorizable.

This is the flaw in the Estonian national ID card we learned about last month.

The paper isn't online yet. I'll post it when it is.

Ouch. This is a bad vulnerability, and it's in systems -- like the Estonian national ID card -- that are critical.

from https://www.schneier.com/blog/

ISO Rejects NSA Encryption Algorithms

The ISO has decided not to approve two NSA-designed block encryption algorithms: Speck and Simon. It’s because the NSA is not trusted to put security ahead of surveillance: A number of them voiced their distrust in emails to one another, seen by Reuters, and in written comments that are part of the process. The suspicions stem largely from internal NSA…

The ISO has decided not to approve two NSA-designed block encryption algorithms: Speck and Simon. It's because the NSA is not trusted to put security ahead of surveillance:

A number of them voiced their distrust in emails to one another, seen by Reuters, and in written comments that are part of the process. The suspicions stem largely from internal NSA documents disclosed by Snowden that showed the agency had previously plotted to manipulate standards and promote technology it could penetrate. Budget documents, for example, sought funding to "insert vulnerabilities into commercial encryption systems."

More than a dozen of the experts involved in the approval process for Simon and Speck feared that if the NSA was able to crack the encryption techniques, it would gain a "back door" into coded transmissions, according to the interviews and emails and other documents seen by Reuters.

"I don't trust the designers," Israeli delegate Orr Dunkelman, a computer science professor at the University of Haifa, told Reuters, citing Snowden's papers. "There are quite a lot of people in NSA who think their job is to subvert standards. My job is to secure standards."

I don't trust the NSA, either.

from https://www.schneier.com/blog/

Proof that HMAC-DRBG has No Back Doors

New research: "Verified Correctness and Security of mbedTLS HMAC-DRBG," by Katherine Q. Ye, Matthew Green, Naphat Sanguansin, Lennart Beringer, Adam Petcher, and Andrew W. Appel. Abstract: We have formalized the functional specification of HMAC-DRBG (NIST 800-90A), and we have proved its cryptographic security — that its output is pseudorandom — using a hybrid game-based proof. We have also proved that…

New research: "Verified Correctness and Security of mbedTLS HMAC-DRBG," by Katherine Q. Ye, Matthew Green, Naphat Sanguansin, Lennart Beringer, Adam Petcher, and Andrew W. Appel.

Abstract: We have formalized the functional specification of HMAC-DRBG (NIST 800-90A), and we have proved its cryptographic security -- that its output is pseudorandom -- using a hybrid game-based proof. We have also proved that the mbedTLS implementation (C program) correctly implements this functional specification. That proof composes with an existing C compiler correctness proof to guarantee, end-to-end, that the machine language program gives strong pseudorandomness. All proofs (hybrid games, C program verification, compiler, and their composition) are machine-checked in the Coq proof assistant. Our proofs are modular: the hybrid game proof holds on any implementation of HMAC-DRBG that satisfies our functional specification. Therefore, our functional specification can serve as a high-assurance reference.

from https://www.schneier.com/blog/

Ross Anderson on the History of the Crypto Wars in the UK

Ross Anderson gave a talk on the history of the Crypto Wars in the UK. I am intimately familiar with the US story, but didn’t know as much about Britain’s verson. Hour-long video. Summary….

Ross Anderson gave a talk on the history of the Crypto Wars in the UK. I am intimately familiar with the US story, but didn't know as much about Britain's verson.

Hour-long video. Summary.

from https://www.schneier.com/blog/

Ethereum Hacks

The press is reporting a $32M theft of the cryptocurrency Ethereum. Like all such thefts, they’re not a result of a cryptographic failure in the currencies, but instead a software vulnerability in the software surrounding the currency — in this case, digital wallets. This is the second Ethereum hack this week. The first tricked people in sending their Ethereum to…

The press is reporting a $32M theft of the cryptocurrency Ethereum. Like all such thefts, they're not a result of a cryptographic failure in the currencies, but instead a software vulnerability in the software surrounding the currency -- in this case, digital wallets.

This is the second Ethereum hack this week. The first tricked people in sending their Ethereum to another address.

This is my concern about digital cash. The cryptography can be bulletproof, but the computer security will always be an issue.

from https://www.schneier.com/blog/

DNI Wants Research into Secure Multiparty Computation

The Intelligence Advanced Research Projects Activity (IARPA) is soliciting proposals for research projects in secure multiparty computation: Specifically of interest is computing on data belonging to different — potentially mutually distrusting — parties, which are unwilling or unable (e.g., due to laws and regulations) to share this data with each other or with the underlying compute platform. Such computations may…

The Intelligence Advanced Research Projects Activity (IARPA) is soliciting proposals for research projects in secure multiparty computation:

Specifically of interest is computing on data belonging to different -- potentially mutually distrusting -- parties, which are unwilling or unable (e.g., due to laws and regulations) to share this data with each other or with the underlying compute platform. Such computations may include oblivious verification mechanisms to prove the correctness and security of computation without revealing underlying data, sensitive computations, or both.

My guess is that this is to perform analysis using data obtained from different surveillance authorities.

from https://www.schneier.com/blog/

NSA Brute-Force Keysearch Machine

The Intercept published a story about a dedicated NSA brute-force keysearch machine being built with the help of New York University and IBM. It’s based on a document that was accidentally shared on the Internet by NYU. The article is frustratingly short on details: The WindsorGreen documents are mostly inscrutable to anyone without a Ph.D. in a related field, but…

The Intercept published a story about a dedicated NSA brute-force keysearch machine being built with the help of New York University and IBM. It's based on a document that was accidentally shared on the Internet by NYU.

The article is frustratingly short on details:

The WindsorGreen documents are mostly inscrutable to anyone without a Ph.D. in a related field, but they make clear that the computer is the successor to WindsorBlue, a next generation of specialized IBM hardware that would excel at cracking encryption, whose known customers are the U.S. government and its partners.

Experts who reviewed the IBM documents said WindsorGreen possesses substantially greater computing power than WindsorBlue, making it particularly adept at compromising encryption and passwords. In an overview of WindsorGreen, the computer is described as a "redesign" centered around an improved version of its processor, known as an "application specific integrated circuit," or ASIC, a type of chip built to do one task, like mining bitcoin, extremely well, as opposed to being relatively good at accomplishing the wide range of tasks that, say, a typical MacBook would handle. One of the upgrades was to switch the processor to smaller transistors, allowing more circuitry to be crammed into the same area, a change quantified by measuring the reduction in nanometers (nm) between certain chip features.

Unfortunately, the Intercept decided not to publish most of the document, so all of those people with "a Ph.D. in a related field" can't read and understand WindsorGreen's capabilities. What sorts of key lengths can the machine brute force? Is it optimized for symmetric or asymmetric cryptanalysis? Random brute force or dictionary attacks? We have no idea.

Whatever the details, this is exactly the sort of thing the NSA should be spending their money on. Breaking the cryptography used by other nations is squarely in the NSA's mission.

from https://www.schneier.com/blog/

Encryption Policy and Freedom of the Press

Interesting law journal article: "Encryption and the Press Clause," by D. Victoria Barantetsky. Abstract: Almost twenty years ago, a hostile debate over whether government could regulate encryption — later named the Crypto Wars — seized the country. At the center of this debate stirred one simple question: is encryption protected speech? This issue touched all branches of government percolating from…

Interesting law journal article: "Encryption and the Press Clause," by D. Victoria Barantetsky.

Abstract: Almost twenty years ago, a hostile debate over whether government could regulate encryption -- later named the Crypto Wars -- seized the country. At the center of this debate stirred one simple question: is encryption protected speech? This issue touched all branches of government percolating from Congress, to the President, and eventually to the federal courts. In a waterfall of cases, several United States Court of Appeals appeared to reach a consensus that encryption was protected speech under the First Amendment, and with that the Crypto Wars appeared to be over, until now.

Nearly twenty years later, the Crypto Wars have returned. Following recent mass shootings, law enforcement has once again questioned the legal protection for encryption and tried to implement "backdoor" techniques to access messages sent over encrypted channels. In the case, Apple v. FBI, the agency tried to compel Apple to grant access to the iPhone of a San Bernardino shooter. The case was never decided, but the legal arguments briefed before the court were essentially the same as they were two decades prior. Apple and amici supporting the company argued that encryption was protected speech.

While these arguments remain convincing, circumstances have changed in ways that should be reflected in the legal doctrines that lawyers use. Unlike twenty years ago, today surveillance is ubiquitous, and the need for encryption is no longer felt by a seldom few. Encryption has become necessary for even the most basic exchange of information given that most Americans share "nearly every aspect of their lives ­-- from the mundane to the intimate" over the Internet, as stated in a recent Supreme Court opinion.

Given these developments, lawyers might consider a new justification under the Press Clause. In addition to the many doctrinal concerns that exist with protection under the Speech Clause, the
Press Clause is normatively and descriptively more accurate at protecting encryption as a tool for secure communication without fear of government surveillance. This Article outlines that framework by examining the historical and theoretical transformation of the Press Clause since its inception.

from https://www.schneier.com/blog/