Entries Tagged "encryption"

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Facebook Is Now Encrypting Links to Prevent URL Stripping

Some sites, including Facebook, add parameters to the web address for tracking purposes. These parameters have no functionality that is relevant to the user, but sites rely on them to track users across pages and properties.

Mozilla introduced support for URL stripping in Firefox 102, which it launched in June 2022. Firefox removes tracking parameters from web addresses automatically, but only in private browsing mode or when the browser’s Tracking Protection feature is set to strict. Firefox users may enable URL stripping in all Firefox modes, but this requires manual configuration. Brave Browser strips known tracking parameters from web addresses as well.

Facebook has responded by encrypting the entire URL into a single ciphertext blob.

Since it is no longer possible to identify the tracking part of the web address, it is no longer possible to remove it from the address automatically. In other words: Facebook has the upper hand in regards to URL-based tracking at the time, and there is little that can be done about it short of finding a way to decrypt the information.

Posted on July 18, 2022 at 9:49 AM • View Comments

NIST Announces First Four Quantum-Resistant Cryptographic Algorithms

NIST’s post-quantum computing cryptography standard process is entering its final phases. It announced the first four algorithms:

For general encryption, used when we access secure websites, NIST has selected the CRYSTALS-Kyber algorithm. Among its advantages are comparatively small encryption keys that two parties can exchange easily, as well as its speed of operation.

For digital signatures, often used when we need to verify identities during a digital transaction or to sign a document remotely, NIST has selected the three algorithms CRYSTALS-Dilithium, FALCON and SPHINCS+ (read as “Sphincs plus”). Reviewers noted the high efficiency of the first two, and NIST recommends CRYSTALS-Dilithium as the primary algorithm, with FALCON for applications that need smaller signatures than Dilithium can provide. The third, SPHINCS+, is somewhat larger and slower than the other two, but it is valuable as a backup for one chief reason: It is based on a different math approach than all three of NIST’s other selections.

NIST has not chosen a public-key encryption standard. The remaining candidates are BIKE, Classic McEliece, HQC, and SIKE.

I have a lot to say on this process, and have written an essay for IEEE Security & Privacy about it. It will be published in a month or so.

Posted on July 6, 2022 at 11:49 AM • View Comments

Forging Australian Driver’s Licenses

The New South Wales digital driver’s license has multiple implementation flaws that allow for easy forgeries.

This file is encrypted using AES-256-CBC encryption combined with Base64 encoding.

A 4-digit application PIN (which gets set during the initial onboarding when a user first instals the application) is the encryption password used to protect or encrypt the licence data.

The problem here is that an attacker who has access to the encrypted licence data (whether that be through accessing a phone backup, direct access to the device or remote compromise) could easily brute-force this 4-digit PIN by using a script that would try all 10,000 combinations….

[…]

The second design flaw that is favourable for attackers is that the Digital Driver Licence data is never validated against the back-end authority which is the Service NSW API/database.

This means that the application has no native method to validate the Digital Driver Licence data that exists on the phone and thus cannot perform further actions such as warn users when this data has been modified.

As the Digital Licence is stored on the client’s device, validation should take place to ensure the local copy of the data actually matches the Digital Driver’s Licence data that was originally downloaded from the Service NSW API.

As this verification does not take place, an attacker is able to display the edited data on the Service NSW application without any preventative factors.

There’s a lot more in the blog post.

Posted on May 23, 2022 at 6:09 AM • View Comments

The NSA Says that There are No Known Flaws in NIST’s Quantum-Resistant Algorithms

Rob Joyce, the director of cybersecurity at the NSA, said so in an interview:

The NSA already has classified quantum-resistant algorithms of its own that it developed over many years, said Joyce. But it didn’t enter any of its own in the contest. The agency’s mathematicians, however, worked with NIST to support the process, trying to crack the algorithms in order to test their merit.

“Those candidate algorithms that NIST is running the competitions on all appear strong, secure, and what we need for quantum resistance,” Joyce said. “We’ve worked against all of them to make sure they are solid.”

The purpose of the open, public international scrutiny of the separate NIST algorithms is “to build trust and confidence,” he said.

I believe him. This is what the NSA did with NIST’s candidate algorithms for AES and then for SHA-3. NIST’s Post-Quantum Cryptography Standardization Process looks good.

I still worry about the long-term security of the submissions, though. In 2018, in an essay titled “Cryptography After the Aliens Land,” I wrote:

…there is always the possibility that those algorithms will fall to aliens with better quantum techniques. I am less worried about symmetric cryptography, where Grover’s algorithm is basically an upper limit on quantum improvements, than I am about public-key algorithms based on number theory, which feel more fragile. It’s possible that quantum computers will someday break all of them, even those that today are quantum resistant.

It took us a couple of decades to fully understand von Neumann computer architecture. I’m sure it will take years of working with a functional quantum computer to fully understand the limits of that architecture. And some things that we think of as computationally hard today will turn out not to be.

EDITED TO ADD (6/14): Since I wrote this, flaws were found in at least four candidates.

Posted on May 16, 2022 at 6:34 AM • View Comments

Samsung Encryption Flaw

Researchers have found a major encryption flaw in 100 million Samsung Galaxy phones.

From the abstract:

In this work, we expose the cryptographic design and implementation of Android’s Hardware-Backed Keystore in Samsung’s Galaxy S8, S9, S10, S20, and S21 flagship devices. We reversed-engineered and provide a detailed description of the cryptographic design and code structure, and we unveil severe design flaws. We present an IV reuse attack on AES-GCM that allows an attacker to extract hardware-protected key material, and a downgrade attack that makes even the latest Samsung devices vulnerable to the IV reuse attack. We demonstrate working key extraction attacks on the latest devices. We also show the implications of our attacks on two higher-level cryptographic protocols between the TrustZone and a remote server: we demonstrate a working FIDO2 WebAuthn login bypass and a compromise of Google’s Secure Key Import.

Here are the details:

As we discussed in Section 3, the wrapping key used to encrypt the key blobs (HDK) is derived using a salt value computed by the Keymaster TA. In v15 and v20-s9 blobs, the salt is a deterministic function that depends only on the application ID and application data (and constant strings), which the Normal World client fully controls. This means that for a given application, all key blobs will be encrypted using the same key. As the blobs are encrypted in AES-GCM mode-of-operation, the security of the resulting encryption scheme depends on its IV values never being reused.

Gadzooks. That’s a really embarrassing mistake. GSM needs a new nonce for every encryption. Samsung took a secure cipher mode and implemented it insecurely.

News article.

Posted on March 4, 2022 at 6:19 AM • View Comments

Decrypting Hive Ransomware Data

Nice piece of research:

Abstract: Among the many types of malicious codes, ransomware poses a major threat. Ransomware encrypts data and demands a ransom in exchange for decryption. As data recovery is impossible if the encryption key is not obtained, some companies suffer from considerable damage, such as the payment of huge amounts of money or the loss of important data. In this paper, we analyzed Hive ransomware, which appeared in June 2021. Hive ransomware has caused immense harm, leading the FBI to issue an alert about it. To minimize the damage caused by Hive Ransomware and to help victims recover their files, we analyzed Hive Ransomware and studied recovery methods. By analyzing the encryption process of Hive ransomware, we confirmed that vulnerabilities exist by using their own encryption algorithm. We have recovered the master key for generating the file encryption key partially, to enable the decryption of data encrypted by Hive ransomware. We recovered 95% of the master key without the attacker’s RSA private key and decrypted the actual infected data. To the best of our knowledge, this is the first successful attempt at decrypting Hive ransomware. It is expected that our method can be used to reduce the damage caused by Hive ransomware.

Here’s the flaw:

The cryptographic vulnerability identified by the researchers concerns the mechanism by which the master keys are generated and stored, with the ransomware strain only encrypting select portions of the file as opposed to the entire contents using two keystreams derived from the master key.

The encryption keystream, which is created from an XOR operation of the two keystreams, is then XORed with the data in alternate blocks to generate the encrypted file. But this technique also makes it possible to guess the keystreams and restore the master key, in turn enabling the decode of encrypted files sans the attacker’s private key.

The researchers said that they were able to weaponize the flaw to devise a method to reliably recover more than 95% of the keys employed during encryption.

Posted on March 1, 2022 at 6:06 AM • View Comments

New DeadBolt Ransomware Targets NAS Devices

There’s a new ransomware that targets NAS devices made by QNAP:

The attacks started today, January 25th, with QNAP devices suddenly finding their files encrypted and file names appended with a .deadbolt file extension.

Instead of creating ransom notes in each folder on the device, the QNAP device’s login page is hijacked to display a screen stating, “WARNING: Your files have been locked by DeadBolt”….

[…]

BleepingComputer is aware of at least fifteen victims of the new DeadBolt ransomware attack, with no specific region being targeted.

As with all ransomware attacks against QNAP devices, the DeadBolt attacks only affect devices accessible to the Internet.

As the threat actors claim the attack is conducted through a zero-day vulnerability, it is strongly advised that all QNAP users disconnect their devices from the Internet and place them behind a firewall.

Posted on January 26, 2022 at 10:04 AM • View Comments

China’s Olympics App Is Horribly Insecure

China is mandating that athletes download and use a health and travel app when they attend the Winter Olympics next month. Citizen Lab examined the app and found it riddled with security holes.

Key Findings:

  • MY2022, an app mandated for use by all attendees of the 2022 Olympic Games in Beijing, has a simple but devastating flaw where encryption protecting users’ voice audio and file transfers can be trivially sidestepped. Health customs forms which transmit passport details, demographic information, and medical and travel history are also vulnerable. Server responses can also be spoofed, allowing an attacker to display fake instructions to users.
  • MY2022 is fairly straightforward about the types of data it collects from users in its public-facing documents. However, as the app collects a range of highly sensitive medical information, it is unclear with whom or which organization(s) it shares this information.
  • MY2022 includes features that allow users to report “politically sensitive” content. The app also includes a censorship keyword list, which, while presently inactive, targets a variety of political topics including domestic issues such as Xinjiang and Tibet as well as references to Chinese government agencies.
  • While the vendor did not respond to our security disclosure, we find that the app’s security deficits may not only violate Google’s Unwanted Software Policy and Apple’s App Store guidelines but also China’s own laws and national standards pertaining to privacy protection, providing potential avenues for future redress.

News article:

It’s not clear whether the security flaws were intentional or not, but the report speculated that proper encryption might interfere with some of China’s ubiquitous online surveillance tools, especially systems that allow local authorities to snoop on phones using public wireless networks or internet cafes. Still, the researchers added that the flaws were probably unintentional, because the government will already be receiving data from the app, so there wouldn’t be a need to intercept the data as it was being transferred.

[…]

The app also included a list of 2,422 political keywords, described within the code as “illegalwords.txt,” that worked as a keyword censorship list, according to Citizen Lab. The researchers said the list appeared to be a latent function that the app’s chat and file transfer function was not actively using.

The US government has already advised athletes to leave their personal phones and laptops home and bring burners.

Posted on January 21, 2022 at 6:06 AM • View Comments

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

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.

Posted on January 18, 2022 at 6:05 AM • View Comments

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Sidebar photo of Bruce Schneier by Joe MacInnis.