During the 1990s, many believed satellite phones were the future of mobile communications. Rapidly expanding terrestrial cellular networks gobbled up most of the market instead. Still, satellite phones retained some technical advantages over cellular ones, principally in remote or rugged areas that are difficult to cover economically with cell towers. Now the TerreStar Genus smart phone is combining the best of both worlds, using a cellular connection when available and tapping into a satellite feed when people wander out of range of a cell tower.
Google gave the first demonstration of its Chrome operating system today, at the same time opening the source code to the public. The company highlighted features that have grown out of what vice president of product management Sundar Pichai called "a fundamentally different model of computing." Unlike other operating systems, which merely incorporate the Internet, Chrome is completely focused on it.
The Chrome OS is based so aggressively on the Internet that devices running it will not even have hard drives, Pichai said, emphasizing that "every app is a Web app." All data will be stored in the cloud, and every application will be accessed through the Chrome browser. Because of this, he added, users will never have to install software or manage updates on the device.
The user interface closely resembles the Chrome browser. When the user opens applications, they appear as tabbed windows across the top of the screen. Users can stick their favorite applications to the desktop with one click, creating permanent tabs for them.
Pichai coyly demonstrated the way the Chrome OS can deal with competitors' file formats. He inserted a USB drive into a laptop running Chrome OS, launching a window that showed that the device contained several Microsoft Excel files. When he clicked on one of the files, the system automatically pulled up the Windows Live Web-based version of Excel, opening the file inside.
"It turns out that Microsoft launched a killer app for Chrome OS," Pichai said, adding that anyone who writes a Web application is writing an application for Chrome by default.
The effect, Pichai hopes, is "speed, simplicity, and security." Today's version of the operating system can boot up in seven seconds and open a Web application in an additional three, he said. Google engineers are working to make those times shorter.
The implications of the Web-focused design were spelled out more fully by Matthew Papakipos, engineering director for Chrome OS. Part of the security scheme for Chrome is that it's hard to make any unauthorized changes to the system, he explained. The root filesystem, which stores the core files needed to make software run, is stored in a read-only format. On top of that, every time the user boots the machine, Chrome OS verifies cryptographic signatures that ensure that the operating system software is properly updated, and matches the build Google has approved.
If the system fails any of these checks, the operating system automatically launches into a recovery procedure and reinstalls the correct version of Chrome, Papakipos said. Normally, reinstalling an operating system is a painful process because of the effect that has on the user's data, settings, and applications. In the case of Chrome, he noted, all of that information will remain unaffected in the cloud.
Some data, such as Wi-Fi settings, is cached on the machine, but Papakipos said this is only to make the system work faster. The data is always synced back to the cloud. The vision, he added, is that a user could eventually get a new device, log in, and find everything running just as it had before, with all the settings still in place.
A study that involved downloading more than three million Facebook profiles has provided the largest-ever snapshot of the methods used by spammers on the world's biggest online social network.
The study, led by researchers at Northwestern University, turned up hundreds of thousands of spam messages, most of which were sent by compromised user accounts in coordinated campaigns similar to those carried out by e-mail spammers.
"For normal users, it mostly remains a myth," says Yan Chen of Northwestern, whose team led the study, "but spam has been a big problem to Facebook."
Reports of user credentials being sold online also motivated the researchers, says Ben Zhao at University of California, Santa Barbara, who with a colleague also contributed to the study, which will be presented at the Internet Measurement Conference in Melbourne, Australia, next month.
Zhao's group had previously collected a dataset of around 11 million Facebook profiles by exploiting the now-discontinued Facebook feature that caused people belonging to regional "networks" to share their profile information with other users by default. Three months worth of data, collected in mid-2009 and representing around 3.5 million people, were used in the study.
The researchers searched for spam in 190 million wall posts--messages posted on one user's profile page by another user--by hunting for Web addresses, even if those addresses were deliberately obscured. Wall posts were grouped into clusters containing the same Web addresses before the malicious clusters were separated from those not sharing spam links by screening the addresses using Web security services.
Altogether 200,000 spam posts from 57,000 different user accounts were picked out from 2.08 million posts containing Web links. These spam posts were generated by 23 million users in total. The study is the first to examine spam activity and features at scale, says Zhao, and it shows Facebook is now a major platform for such activity. "The results are quite surprising to me -- that even last year there was so much activity," he says. "I think this is the harbinger of things to come, as Facebook attracts more of the wrong kind of attention."
Many messages tempted users with offers of free swag such as ringtones, or used a social trap like announcing that someone had a "crush" on them. Around 70 percent of the messages were "phishing attacks," meaning they directed users to websites that attempt to trick them into divulging personal information. But most were attempts to gain Facebook account details, a strategy that could help send out more spam.
"We expected that attackers would mostly create new accounts to send spam attacks, but in fact, most are sent via compromised accounts," says Chen. "That may be harder than creating new accounts, but it is more effective to send spams to real friends."
Different accounts often sent the same spam, sometimes in simultaneous bursts of activity. "These are coordinated spam campaigns, as we see in e-mail spam," says Zhao.
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