Entries Tagged "authentication"

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Heartbeat as Biometric Password

There’s research in using a heartbeat as a biometric password. No details in the article. My guess is that there isn’t nearly enough entropy in the reproducible biometric, but I might be surprised. The article’s suggestion to use it as a password for health records seems especially problematic. “I’m sorry, but we can’t access the patient’s health records because he’s having a heart attack.”

I wrote about this before here.

Posted on January 19, 2017 at 6:22 AMView Comments

Guessing Credit Card Security Details

Researchers have found that they can guess various credit-card-number security details by spreading their guesses around multiple websites so as not to trigger any alarms.

From a news article:

Mohammed Ali, a PhD student at the university’s School of Computing Science, said: “This sort of attack exploits two weaknesses that on their own are not too severe but when used together, present a serious risk to the whole payment system.

“Firstly, the current online payment system does not detect multiple invalid payment requests from different websites.

“This allows unlimited guesses on each card data field, using up to the allowed number of attempts—typically 10 or 20 guesses—on each website.

“Secondly, different websites ask for different variations in the card data fields to validate an online purchase. This means it’s quite easy to build up the information and piece it together like a jigsaw.

“The unlimited guesses, when combined with the variations in the payment data fields make it frighteningly easy for attackers to generate all the card details one field at a time.

“Each generated card field can be used in succession to generate the next field and so on. If the hits are spread across enough websites then a positive response to each question can be received within two seconds—just like any online payment.

“So even starting with no details at all other than the first six digits—which tell you the bank and card type and so are the same for every card from a single provider—a hacker can obtain the three essential pieces of information to make an online purchase within as little as six seconds.”

That’s card number, expiration date, and CVV code.

From the paper:

Abstract: This article provides an extensive study of the current practice of online payment using credit and debit cards, and the intrinsic security challenges caused by the differences in how payment sites operate. We investigated the Alexa top-400 online merchants’ payment sites, and realised that the current landscape facilitates a distributed guessing attack. This attack subverts the payment functionality from its intended purpose of validating card details, into helping the attackers to generate all security data fields required to make online transactions. We will show that this attack would not be practical if all payment sites performed the same security checks. As part of our responsible disclosure measure, we notified a selection of payment sites about our findings, and we report on their responses. We will discuss potential solutions to the problem and the practical difficulty to implement these, given the varying technical and business concerns of the involved parties.

BoingBoing post:

The researchers believe this method has already been used in the wild, as part of a spectacular hack against Tesco bank last month.

MasterCard is immune to this hack because they detect the guesses, even though they’re distributed across multiple websites. Visa is not.

Posted on December 5, 2016 at 6:25 AMView Comments

Self-Propagating Smart Light Bulb Worm

This is exactly the sort of Internet-of-Things attack that has me worried:

“IoT Goes Nuclear: Creating a ZigBee Chain Reaction” by Eyal Ronen, Colin OFlynn, Adi Shamir and Achi-Or Weingarten.

Abstract: Within the next few years, billions of IoT devices will densely populate our cities. In this paper we describe a new type of threat in which adjacent IoT devices will infect each other with a worm that will spread explosively over large areas in a kind of nuclear chain reaction, provided that the density of compatible IoT devices exceeds a certain critical mass. In particular, we developed and verified such an infection using the popular Philips Hue smart lamps as a platform. The worm spreads by jumping directly from one lamp to its neighbors, using only their built-in ZigBee wireless connectivity and their physical proximity. The attack can start by plugging in a single infected bulb anywhere in the city, and then catastrophically spread everywhere within minutes, enabling the attacker to turn all the city lights on or off, permanently brick them, or exploit them in a massive DDOS attack. To demonstrate the risks involved, we use results from percolation theory to estimate the critical mass of installed devices for a typical city such as Paris whose area is about 105 square kilometers: The chain reaction will fizzle if there are fewer than about 15,000 randomly located smart lights in the whole city, but will spread everywhere when the number exceeds this critical mass (which had almost certainly been surpassed already).

To make such an attack possible, we had to find a way to remotely yank already installed lamps from their current networks, and to perform over-the-air firmware updates. We overcame the first problem by discovering and exploiting a major bug in the implementation of the Touchlink part of the ZigBee Light Link protocol, which is supposed to stop such attempts with a proximity test. To solve the second problem, we developed a new version of a side channel attack to extract the global AES-CCM key that Philips uses to encrypt and authenticate new firmware. We used only readily available equipment costing a few hundred dollars, and managed to find this key without seeing any actual updates. This demonstrates once again how difficult it is to get security right even for a large company that uses standard cryptographic techniques to protect a major product.

EDITED TO ADD: BoingBoing post. Slashdot thread.

Posted on November 9, 2016 at 6:54 AMView Comments

Powerful Bit-Flipping Attack

New research: “Flip Feng Shui: Hammering a Needle in the Software Stack,” by Kaveh Razavi, Ben Gras, Erik Bosman Bart Preneel, Cristiano Giuffrida, and Herbert Bos.

Abstract: We introduce Flip Feng Shui (FFS), a new exploitation vector which allows an attacker to induce bit flips over arbitrary physical memory in a fully controlled way. FFS relies on hardware bugs to induce bit flips over memory and on the ability to surgically control the physical memory layout to corrupt attacker-targeted data anywhere in the software stack. We show FFS is possible today with very few constraints on the target data, by implementing an instance using the Rowhammer bug and memory deduplication (an OS feature widely deployed in production). Memory deduplication allows an attacker to reverse-map any physical page into a virtual page she owns as long as the page’s contents are known. Rowhammer, in turn, allows an attacker to flip bits in controlled (initially unknown) locations in the target page.

We show FFS is extremely powerful: a malicious VM in a practical cloud setting can gain unauthorized access to a co-hosted victim VM running OpenSSH. Using FFS, we exemplify end-to-end attacks breaking OpenSSH public-key authentication, and forging GPG signatures from trusted keys, thereby compromising the Ubuntu/Debian update mechanism. We conclude by discussing mitigations and future directions for FFS attacks.

Posted on August 16, 2016 at 7:09 AMView Comments

Google Moving Forward on Automatic Logins

Google is trying to bring this to Android developers by the end of the year:

Today, secure logins—like those used by banks or in the enterprise environment—often require more than just a username and password. They tend to also require the entry of a unique PIN, which is generally sent to your phone via SMS or emailed. This is commonly referred to as two-factor authentication, as it combines something you know (your password) with something you have in your possession, like your phone.

With Project Abacus, users would instead unlock devices or sign into applications based on a cumulative “Trust Score.” This score would be calculated using a variety of factors, including your typing patterns, current location, speed and voice patterns, facial recognition, and other things.

Basically, the system replaces traditional authentication—something you know, have, or are—with surveillance. So maybe this is a good idea, and maybe it isn’t. The devil is in the details.

EDITED TO ADD: It’s being called creepy. But, as we’ve repeatedly learned, creepy is subjective. What’s creepy now is perfectly normal two years later.

Posted on May 24, 2016 at 8:35 AMView Comments

Hacking Gesture-Based Security

Interesting research: Abdul Serwadda, Vir V. Phoha, Zibo Wang, Rajesh Kumar, and Diksha Shukla, “Robotic Robbery on the Touch Screen,” ACM Transactions on Information and System Security, May 2016.

Abstract: Despite the tremendous amount of research fronting the use of touch gestures as a mechanism of continuous authentication on smart phones, very little research has been conducted to evaluate how these systems could behave if attacked by sophisticated adversaries. In this article, we present two Lego-driven robotic attacks on touch-based authentication: a population statistics-driven attack and a user-tailored attack. The population statistics-driven attack is based on patterns gleaned from a large population of users, whereas the user-tailored attack is launched based on samples stolen from the victim. Both attacks are launched by a Lego robot that is trained on how to swipe on the touch screen. Using seven verification algorithms and a large dataset of users, we show that the attacks cause the system’s mean false acceptance rate (FAR) to increase by up to fivefold relative to the mean FAR seen under the standard zero-effort impostor attack. The article demonstrates the threat that robots pose to touch-based authentication and provides compelling evidence as to why the zero-effort attack should cease to be used as the benchmark for touch-based authentication systems.

News article. Slashdot thread.

Posted on May 12, 2016 at 5:31 AMView Comments

New Credit Card Scam

A criminal ring was arrested in Malaysia for credit card fraud:

They would visit the online shopping websites and purchase all their items using phony credit card details while the debugging app was activated.

The app would fetch the transaction data from the bank to the online shopping website, and trick the website into believing that the transaction was approved, when in reality, it had been declined by the bank.

The syndicates would later sell the items they had purchased illegally for a much lower price.

The problem here seems to be bad systems design. Why should the user be able to spoof the merchant’s verification protocol with the bank?

Posted on May 11, 2016 at 6:34 AMView Comments

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Sidebar photo of Bruce Schneier by Joe MacInnis.