If you use your phone GSM (AT & T and T-Mobile in the U.S.), you likely have a few months before it will be easy for almost any spy on your message.
Security researcher Karsten Nohl begins with an open source distributed computing project to crack the encryption used on GSM phones and compile it into a code book, which can be used to decode the conversations and any data that will be sent to and from your phone.
Karsten Nohl told about their distributed computing open source AE / 1 cracking project at hacking conference Random.
(Credit: Hacking at random)
He hopes that by doing this will stimulate the cellular providers to improve the security of its services and fix the shortcoming that has existed for 15 years and about 3 billion mobile users.
“We do not create a vulnerability, but lack of transparency, which has operated very well,” he said in a telephone interview on Monday.
“Obviously, what we’re doing the attack is more practical and much cheaper, and, of course, there is a moral question of whether we do it,” he said. “But more importantly, we will inform (people) on the long-standing vulnerability and, hopefully, better warning systems to accept this.”
This weakness in the encryption used on the phones, A5 / 1, has been known for years. There are at least four commercial tools that will allow to decrypt messages, GSM range in price from $ 100000 to $ 250000 depending on how quickly you want the software to work, “said Nohl, who had previously disseminated information, weaknesses in wireless smart card chip used in transit systems.
It takes 80 high-performance computers for about three months to make a brute force attack A5 / 1 and create a big look-up tables, which will serve as a code book, said Nohl, which announced the project at random Hacking Conference in the Netherlands 10 days ago.
Using code book, everyone could get the encryption key to any challenge GSM, SMS messages, or other message encrypted A5 / 1 and listen to the call or read the data in clear text. If 160 people donate their computing resources to the project, it should only take a half months to complete, he said.
Participants download software and after three months they shared with files created by others, by uploading, for example, Nohl said. “We have no connection with them,” he added.
After the look-up table is created it will be available for any use.
Distributed computing, which has long been used for research and academic purposes, such as SETI @ Home, and some companies have established businesses all over, not only solves the technical obstacles to cracking A5 / 1 code, but it may solve a legal nature, too.
Several years ago a similar project was started cracking GSM, but was stopped before it was completed after being harassed, the researchers may be the provider of cellular communication, Nohl said. Extending efforts among the participants and do not have it centralized, new efforts will be less vulnerable to outside interference, “he said.
Nohl had no definite legal implications of the project, but said that it was likely that the use of such look-up table is illegal, but legal ownership, as the company that openly advertise their tables for sale.
T-Mobile spokesman said the company had no comment on the matter.
AT & T, Mark Siegel, the representative said: “We take extraordinary precautions to protect the privacy of our customers and use various tools, many technical and some human rights approaches. I can not go into details for security reasons.” He declined to elaborate or comment further.
Precautions
Carriers must update the encryption or move voice services to 3G, which is much stronger encryption, Nohl said.
At the same time, people can use certain products encrypt the phone as Cellcrypt or mobile phones with their own encryption, Nohl said. Amnesty International and Greenpeace used phones with strong encryption, for example, but it only works if both parties in a conversation using the same technology, “he said.
For data encryption is Pretty Good Privacy (PGP) for e-mail and virtual private network (VPN) software to connect to the corporate network, he said.
Encryption problem is especially serious for people engaged in online banking, where banks are using text messages as authentication tokens. Banks should instead offer RSA SecurID tokens or send a one-time pass phrases via regular mail, Nohl said.
“I think that potentially it could have big impact, as the breaking of WEP (Wired Equivalent Privacy) was a few years ago,” said Stan Shatt, security practice director of ABI Research. “It shook up the industry quite a bit.”
As a result of violations that encryption, the company did not want to rely on wireless local area network such Wi-Fi Alliance pushed the interim standard, which strengthened the encryption scheme, “he said.
“Vendors will jump in interim solutions, as Cellcrypt”, said the Shatt. “Mobile operators themselves have to jump and to offer additional levels of encryption within the managed services offers to people who want a higher level of encryption.”
Nevertheless, consumers are unlikely to pay for additional growth of encryption, he said.
Snoop on the phone to someone who would be the spy must be within view of the purpose, the Shatt al-Said. Or, spies could point to a recording device in the direction of the building and capture all the conversations were close, “he said.
“If you stand outside the building a competitor can get the product of conversations between managers and confidential information about corporations, as well as acquisitions,” he said. “Corporation put more sensitive information through their phones, in general, than they are on their e-mail.”
