Vulnerabilities / Threats
12/29/2009
02:23 PM
Connect Directly
RSS
E-Mail
50%
50%

Hacker Breaks GSM Mobile Phone Code

A German computer scientist has cracked the encryption algorithm that secures 80% of the world's mobile phones, but it's far from a practical attack.

A German computer scientist working with a team of experts has broken the code used to secure about 80% of the world's mobile phones. But the group responsible for protecting GSM communications said Tuesday the feat is a "long way from being a practical attack."

Researcher Karsten Nohl, a former graduate student at the University of Virginia, revealed his decryption methods this week at the Chaos Communication Conference in Berlin, the largest hackers conference in Europe. Nohl and a team of two dozen other experts worked for five months to crack the security algorithm that protects Global System for Mobile communications.

GSM is the world's most widely used phone technology, accounting for more than 4 billion mobile phones. To prevent eavesdropping, the technology uses an encryption algorithm called A5/1 developed by the GSM Association.

To break the code, Nohl and the other researchers used networks of computers to crunch through the trillions of mathematical possibilities. The result was the development of a code book comprising 2 TB of data that's compiled into cracking tables. The tables can be used as a kind of reverse phone book to determine the encryption key used to secure a GSM mobile phone conversation or text message.

Before the latest hack, hundreds of thousands of dollars of computer equipment was needed to break the GSM code, mostly limiting hacking to government agencies. Nohl told the conference that someone with the code book could eavesdrop on GSM communications using about $30,000 worth of computer gear, making such illegal activity possible by many more criminal organizations.

On Tuesday, a GSMA statement sent to InformtationWeek by e-mail said Nohl's work "isn't something that we take lightly at all." Nevertheless, the organization said, the hack did not present an immediate danger to GSM security.

"All in all, we consider this research, which appears to be motivated in part by commercial considerations, to be a long way from being a practical attack on GSM," the organization said.

The GSMA said in a statement that over the last few years, a number of academic papers have explained, in theory, how the A5/1 algorithm, which is more than 20 years old, could be compromised. "However, none to date have led to a practical attack capability being developed against A5/1 that can be used on live, commercial GSM networks," the group said.

One area not covered by Nohl's work, according to the GSMA, is how the GSM call would be identified and recorded from the radio interface. To do that, a hacker would need a radio receiver system and the signal processing software necessary to process the raw radio data.

"So far, this aspect of the methodology has not been explained in any detail and we strongly suspect that the teams attempting to develop an intercept capability have underestimated its practical complexity," the GSMA said.

Nevertheless, the group recognizes that A5/1 needs to be replaced, and is in the process of phasing in a new security algorithm called A5/3

Comment  | 
Print  | 
More Insights
Register for Dark Reading Newsletters
Partner Perspectives
What's This?
In a digital world inundated with advanced security threats, Intel Security seeks to transform how we live and work to keep our information secure. Through hardware and software development, Intel Security delivers robust solutions that integrate security into every layer of every digital device. In combining the security expertise of McAfee with the innovation, performance, and trust of Intel, this vision becomes a reality.

As we rely on technology to enhance our everyday and business life, we must too consider the security of the intellectual property and confidential data that is housed on these devices. As we increase the number of devices we use, we increase the number of gateways and opportunity for security threats. Intel Security takes the “security connected” approach to ensure that every device is secure, and that all security solutions are seamlessly integrated.
Featured Writers
White Papers
Cartoon
Current Issue
Dark Reading's October Tech Digest
Fast data analysis can stymie attacks and strengthen enterprise security. Does your team have the data smarts?
Flash Poll
Video
Slideshows
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2013-0334
Published: 2014-10-31
Bundler before 1.7, when multiple top-level source lines are used, allows remote attackers to install arbitrary gems by creating a gem with the same name as another gem in a different source.

CVE-2014-2334
Published: 2014-10-31
Multiple cross-site scripting (XSS) vulnerabilities in the Web User Interface in Fortinet FortiAnalyzer before 5.0.7 allow remote attackers to inject arbitrary web script or HTML via unspecified vectors, a different vulnerability than CVE-2014-2336.

CVE-2014-2335
Published: 2014-10-31
Multiple cross-site scripting (XSS) vulnerabilities in the Web User Interface in Fortinet FortiManager before 5.0.7 allow remote attackers to inject arbitrary web script or HTML via unspecified vectors, a different vulnerability than CVE-2014-2336.

CVE-2014-2336
Published: 2014-10-31
Multiple cross-site scripting (XSS) vulnerabilities in the Web User Interface in Fortinet FortiManager before 5.0.7 and FortiAnalyzer before 5.0.7 allow remote attackers to inject arbitrary web script or HTML via unspecified vectors, a different vulnerability than CVE-2014-2334 and CVE-2014-2335.

CVE-2014-3366
Published: 2014-10-31
SQL injection vulnerability in the administrative web interface in Cisco Unified Communications Manager allows remote authenticated users to execute arbitrary SQL commands via a crafted response, aka Bug ID CSCup88089.

Best of the Web
Dark Reading Radio
Archived Dark Reading Radio
Follow Dark Reading editors into the field as they talk with noted experts from the security world.