Topics

16

Science and Information / A malware called BadUSB

« on: December 16, 2014, 01:03:53 PM »

Reference: http://www.techworm.net/2014/10/badusb-malware-code-on-github.html

What is BadUSB?

The malware which is dubbed BadUSB,  reprograms embedded firmware to give USB devices new, covert and most powerful capabilities. In a demo at Black Hat security conference in Las Vegas, a USB drive was infected and showed its ability to act as a keyboard that surreptitiously types malicious commands into attached computers.

Another USB was similarly be reprogrammed to act as a network card that causes connected computers to connect to malicious sites impersonating Google, Facebook or other trusted destinations. The demo showed that similar hacks could work against Android phones when attached to targeted computers. The malware is so huge that it can work on almost any USB linked devices like Web cams, keyboards, smart phones etc.

BadUSB on Github

Researchers Wilson and Caudill reversed-engineered USB firmware and reprogrammed it to launch various attacks. They then put the code for BadUSB on Github with a intent of letting all the users know abouts its effects.

“The belief we have is that all of this should be public. It shouldn’t be held back. So we’re releasing everything we’ve got,” Caudill told the Derbycon audience on Friday. “This was largely inspired by the fact that [SR Labs] didn’t release their material. If you’re going to prove that there’s a flaw, you need to release the material so people can defend against it.”

Caudill and Wilson discussed various scenarios where BadUSB can be used.  Prominent among them and most deadliest is the USB device to emulate a keyboard and issue commands on behalf of a logged-in user to exfiltrate data or install malware.

Unpatchable!!!

BadUSB remains unpatchable at the moment.  The reason according to the both the researchers, is that the USB controller chips in peripherals can be reprogrammed to spoof other devices and there’s little or no protection to prevent anyone from doing so.  They also feel that since USBs are mass manufactured these days and it proves that anyone can input the code to insert the malware and take command of any system, perhaps the USB manufacturers will be under pressure to fix it soon.

“If the only people who can do this are those with significant budgets, the manufacturers will never do anything about it,” Caudill told Wired. “You have to prove to the world that it’s practical, that anyone can do it…That puts pressure on the manufactures to fix the real issue.”

The researchers also hope that putting the code on Github would encourage companies and white hat researchers to find a fix for the malware.

Further tests have determined that almost half the USB devices available as of now are affected with this vulnerability, read more about the test results here.

17

Science and Information / WINDOWS XP VULNERABLE FOREVER DUE TO ZERO-DAY FLAW

« on: December 16, 2014, 12:38:34 PM »

Reference (Copied): http://www.latesthackingnews.com/2014/05/29/windows-xp-vulnerable-forever-due-to-zero-day-flaw/

Microsoft most likely developed a patch for the zero-day flaw since October 2013, when it was first made aware of the vulnerability in Internet Explorer 8, but the company had to delay its release due to some other publicly disclosed security flaws that affected a wider array of users.

The problem in this case is why Microsoft needs so much time to address this new zero-day and why the company delays the release if the patch is already available.

Basically, if your existing Windows installation can run a newer version of Internet Explorer than 8.0, it would be quite a good idea to update and thus avoid getting your computer hijacked if an exploit is being developed.

At the same time, virtually everyone can replace Internet Explorer with a different third-party browser that’s obviously not affected by the flaw and keeps you on the safe side.

Microsoft has confirmed the existence of the issue but hasn’t said anything about the release date of a patch. While the company might opt for an out-of-band patch, it could also very well wait until the next Patch Tuesday on June 10, when some other updates are also planned.

18

Science and Information / What database actually FACEBOOK uses?

« on: December 16, 2014, 11:01:54 AM »

Reference: http://www.techworm.net/2013/05/what-database-actually-facebook-uses.html

This article takes a look at some of the software and techniques they use to accomplish their mission.

MYSQL::

Facebook primarily uses MySQL for structured data storage such as wall posts, user information, timeline etc.  This data is replicated between their various data centers.

MEMCACHED :

It is also important to note that Facebook makes heavy use of Memcached,a memory caching system that is used to speed up dynamic database driven websites by caching data and objects in RAM to reduce reading time.Memcached is Facebook’s primary form of caching and greatly reduces the database load. Having a
caching system allows Facebook to be as fast as it is at recalling your data. If it doesn’t have to go to the database it will just fetch your data from the cache based on your user ID.

HAYSTACK ::

The Photos application is one of Facebook’s most popular features. Up to date, users
have uploaded over 15 billion photos which make Facebook the biggest photo sharing website. For each uploaded photo, Facebook generates and stores four images of different sizes, which translates to a total of 60 billion images and 1.5PB of storage. The current growth rate is 220 million new photos per week, which translates to 25TB of additional storage consumed weekly.
Implements a HTTP based photo server which stores photos in a generic object store called Haystack.

CASSANDRA :
 The Apache Cassandra database is the right choice when you need scalability and  high availability without compromising performance. Facebook uses it for its Inbox search.

SCRIBE :
Scribe is a flexible logging system that Facebook uses for a multitude of purposes
internally. It’s been built to be able to handle logging at the scale of Facebook, and automatically handles new logging categories as they show up.

VARNISH :
 Varnish is an HTTP accelerator which can act as a load balancer and also cache content which can then be served lightning-fast. Facebook uses Varnish to serve photos and profile pictures,handling billions of requests every day.

HIPHOP FOR PHP :

HipHop for PHP is a set of PHP execution engines. HipHop was developed by Facebook and was released as open source in early 2010. To date, Facebook has achieved morethan a 6x reduction in CPU utilization for the site using HipHop as compared with Apache and Zend PHP.Facebook is able to move fast and maintain a high number of engineers who are able to work across the entire codebase.
 
So, while “What database does Facebook use?” seems like a simple question, you can see that FACEBOOK developers have added a variety of other systems to make it truly web scalable over their 500million users.

19

Science and Information / Five million Gmail addresses and passwords dumped online

« on: December 16, 2014, 09:50:28 AM »

Reference: http://www.technotification.com/2014/09/gmail-password-dumped.html

A few months ago  A user with online alias “tvskit ” posted an archive file containing nearly 5 million Gmail addresses and plain text passwords on Bitcoin security forum called btcsec.com and claimed that over 60 percent of credentials found inside are valid.
CSIS researchers not only analyzed the data but also concluded that it is up to 3 years old based on correlations with past leaks.
This means that many of the leaked passwords do not correspond to Gmail or Google accounts, but to accounts on other sites where users have used their Gmail addresses as the user name.

CSIS has confirmation that at least five of the leaked user name and password pairs were never used as log-in credentials for Gmail or Google accounts. This enforces the idea that the data comes from compromises outside Google, though it’s possible that they were all perpetrated by a single individual or group, Kruse said.

“The security of our users is of paramount importance to us,” a Google representative said Wednesday via email. “We have no evidence that our systems have been compromised, but whenever we become aware that an account has been compromised, we take steps to help our users secure their accounts.”

Even if many of the leaked credentials turn out not to be from Google, affected users might still want to change their passwords on websites where they used their Gmail address as the user name. A website called isleaked.com allows users to check if their email address is among those leaked.

Informtion Source: PCworld.com , CSIS and BST forum

20

Science and Information / Hackers Are using Gmail drafts as command and control to steal data

« on: December 16, 2014, 09:38:31 AM »

Reference: http://www.technotification.com/2014/10/hacker-use-gmail-drafts-for-hacking.html

Back in August, Germany’s anti-malware solutions provider G Data Software identified stealthy malware that had gone undetected since 2012.

They dubbed the remote administration tool (RAT) Win32.Trojan.IcoScript.A and remarked that it was particularly nasty due to the way it abused webmail for its command and control (C&C) communications. Although IcoScript was using Yahoo email, G Data predicted that it could just as easily abuse Facebook, LinkedIn or Gmail. And now a variant of that malware is using Gmail drafts that open in invisible Internet Explorer windows and act as the command and control to steal data.

As written on wired .com :

Williamson (a security researcher at Shape) says the new infection is in fact a variant of a remote access trojan (RAT) called Icoscript first found by the German security firm G-Data in August. At the time, G-Data said that Icoscript had been infecting machines since 2012, and that its use of Yahoo Mail emails to obscure its command and control had helped to keep it from being discovered. The switch to Gmail drafts, says Williamson, could make the malware stealthier still.

Thanks in part to that stealth, Shape doesn’t have any sense of just how many computers might be infected with the Icoscript variant they found. But given its data-stealing intent, they believe it’s likely a closely targeted attack rather than a widespread infection.

For victims of the malware, Shape says there’s no easy way to detect its surreptitious data theft without blocking Gmail altogether. The responsibility may instead fall on Google to make its webmail less friendly to automated malware. A Google spokesperson responded to an email from WIRED with only a statement that “our systems actively track malicious and programmatic usage of Gmail and we quickly remove abusive accounts we identify.”

G Data concluded in its write up:

The malware abused Microsoft Windows Component Object Model (COM) technology to control Internet Explorer. IE would open in an invisible, or hidden, window and connect to specific websites, enter credentials to access an email account, execute files, check or uncheck checkboxes, press buttons on a webpage, fill in form data on a site, export data and more.

The following were listed as advantages for malware developers to exploit COM, which can control IE, and manipulate the browser that is being used by a legitimate user:

The HTTP communication is performed by the user’s iexplore.exe process (not by the malware itself).
If the targeted infrastructure uses a proxy (with authentication), the malware can reuse the proxy token stored in the user session. The malware developers don’t have to worry about the proxy configuration on the infected machine.
Analysis by reverse engineering is more complicated – there’s no obvious evidence of malicious network behavior or socket usage, etc.
The user does not usually notice the additional communication being carried out by the browser – the session is hidden.

21

Science and Information / Google Spending $1 Billion On Satellites To Cover Earth In Wi-Fi – WSJ

« on: December 16, 2014, 08:48:37 AM »

Reference: http://www.technotification.com/2014/06/google-spending-1-billion-on-satellites.html

Google plans to spend over $1 billion on a fleet of satellites that will be used to provide internet to parts of the world that currently lack digital connections. Google will use 180 “small, high-capacity satellites” that will orbit the Earth at low altitudes. Led by Greg Wyler, who set up satellite startup O3b Networks Ltd, Google has been on a hiring spree to recruit engineers from satellite company Space Systems/Loral LLC. The project is scoped to provide internet to areas around the world without wired connections, and cost between $1 billion to more than $3 billion, depending on the network’s final design and size.

 Google is running tests with internet providing balloons, and it’s bought a drone company to cover the world in Wi-Fi, too. While previous attempts to smother the world in internet via satellite have proved unsuccessful, that’s largely been due to escalating costs. If the the report is accurate, Google is now working on three high-profile projects to use airborne craft to connect the world. Clearly, cost isn’t too much of a concern for Page & Co.

Question is what is the cost? Is it the money or  ...........

22

Science and Information / Verizon’s New, Encrypted Calling App Comes Pre-Hacked for the NSA

« on: December 15, 2014, 07:16:01 AM »

Reference: http://www.techworm.net/2014/12/verizons-new-app-verizon-voice-cypher-comes-built-backdoor-nsa.html

Verizon has introduced a new product called Verizon Voice Cypher in the US markets yesterday.  The Verizon Voice Cypher has been developed by Verizon in collaboration with a encryption company called Cellcrypt and offers end-to-end encryptions to enterprises and government customers for voice calls on iOS, Android and BlackBerry devices.  This can be done with a special App that is being offered by Verizon which will allow Verizon customers to speak securely regardless of their wireless carrier. This App will also connect the users to their organisations secure system.

Sounds good!!! Well there is a catch in this App comes with a built in backdoor which will let the law enforcement agencies access to otherwise secure phone conversations.

Both Verizon and CellCrypt have stated that government agencies will be able to access communications that take place over Voice Cypher as long as they give legitimate proof of the requirement for doing so.  Cellcrypt’s VP, Seth Polansky denies leaving such a backdoor is a security risk, “It’s only creating a weakness for government agencies,” he says. “Just because a government access option exists, it doesn’t mean other companies can access it.”

To be fair to Verizon, the US Communications Assistance for Law Enforcement Act requires it to build network which can be wiretapped by law enforcement agencies. But the corollary for this law is that Verizon has to decrypt communications for government authorities only if they have technology of doing it.  In other words, If Verizon and Cellcrypt had build their encryption that they didnt have technology to decrypt, they wouldn’t come under the purview of this act.  Google and Apple have structured their end-to-end encryption in iOS 8 and Android 5.0 lollipop similarly.

While Verizon and Cellcrypt believe that they have done nothing wrong in keeping a backdoor open for the authorities and hope that big businesses and governments will opt for Verizon Voice Cypher, privacy activists beg to differ. With Verizon courting controversy over putting headers in the HTTP section to track its customers and gauge their spending habits and the pre-installed DT Ignite App shipped on Android smartphones and tablets, it may just be giving ammo to the privacy advocacy groups to raise further banner of  rights violations. ACLU believes this product will fail, ACLU’s Chris Soghoian believes that Verizon’s approach is unlikely to have wide appeal because of Verizon’s decision not to keep out law enforcement.

Other set of people believe that a pre-designed backdoor or access point is a open door invitation for cybercriminals to exploit. Only time will tell if indeed, Voice Cypher succeeds in making enterprises and governments believe in it inspite of a big gaping hole which authorities can tune into anytime.

23

Science and Information / HOW DO YOU KNOW YOUR COMPUTER IS INFECTED AND ITS PRECAUTION.

« on: December 15, 2014, 07:11:10 AM »

Reference: http://www.techworm.net/2013/05/how-do-you-know-your-computer-is.html

How do you know your computer is infected?there is no particular way to identify that your computer has been infected with malicious code. Some infections can completely destroy files and shut down your computer, while others can only  affect your computer’s normal operations. Be aware of any unusual or unexpected behaviors. If you are running anti-virus software, it may alert you that it has found malicious code on your computer. The anti-virus software may be able to clean the malicious code automatically, but if it can’t, you will need to take additional steps.
What can you do if you are infected?

Minimize the damage :- If you are at work and have access to an IT department, contact them immediately. The sooner they can investigate and clean your computer, the less damage to your computer and other computers on the network. If you are at your home computer or a laptop, disconnect your computer from the internet. By removing the internet connection, you prevent virus from being able to access your computer and perform tasks such as locating personal data, manipulating or deleting files, or using your computer to attack other computers.

Remove the malicious code:- If you have anti-virus software installed on your computer, update the virus definitions (if possible), and perform a manual scan of your entire system. If you do not have anti-virus software, you can purchase it at a local computer store . If the software can’t locate and remove the infection, you may need to reinstall your operating system, usually with a system restore disk that is often supplied with a new computer. Note that reinstalling or restoring the operating system typically erases all of your files and any additional software that you have installed on your computer. After reinstalling the operating system and any other software, install all of the appropriate patches to fix known vulnerabilities.

How can you reduce the risk of another infection?

Dealing with the presence of malicious code on your computer can be a bad experience that can cost you time, money, and data. The following recommendations will build your defense against future attacks:-

use and maintain anti-virus software – Anti-virus software recognizes and protects your computer against most known viruses. However, attackers are continually writing new viruses, so it is important to keep your anti-virus software current .

change your passwords – Your original passwords may have been compromised during the infection, so you should change them. This includes passwords for web sites that may have been cached in your browser. Make the passwords difficult for attackers to guess .

keep software up to date – Install software patches so that attackers can’t take advantage of known problems or vulnerabilities . Many operating systems offer automatic updates. If this option is available, you should enable it.

install or enable a firewall – Firewalls may be able to prevent some types of infection by blocking malicious traffic before it can enter your computer . Some operating systems actually include a firewall, but you need to make sure it is enabled.

use anti-spyware tools – Spyware is a common source of viruses, but you can minimize the number of infections by using a legitimate program that identifies and removes spyware.

follow good security practices – Take appropriate precautions when using email and web browsers so that you reduce the risk that your actions will trigger an infection .

24

Science and Information / free SSL certificates for entire WEB to protect web data

« on: November 25, 2014, 02:36:05 PM »

Reference: http://www.technotification.com/2014/11/lets-encrypt-a-certificate-authority-giving-free-ssl-certificates-for-entire-web.html

Electronic frontier foundation has partnered with Mozilla , CISCO and Akamai for free HTTPS certificates for all the servers running at the beginning of 2015. Till now applying the encryption has been a expensive process but now after the launch of Let’s Encrypt Web will b more secure from all types of notorious Hackers.

It is a result of the effort applied by Firefox of Mozilla , CISCO and Akamai technologies , Electronic frontier Foundation , EdenTrust and Some researchers from Michigan Any web developer who wants to test the service can go to GITHUB and CHECK the code which is available there for public use.

You should keep in mind that the service is currently is not fully functional and if you will pay o hid to it then you might get various certificate warnings.

EFF Technology Director Peter Eckersley Said in a staement that The above project should be able to boost everyday data protection for almost everyone on the Web.

” Let’s Encrypt is a new free https certificate authority, built on a foundation of cooperation and openness, that lets everyone be up and running with basic server certificates for their domains through a simple one-click process,” its official website explains. “For many server operators, getting even a basic server certificate is just too much of a hassle. The application process can be confusing. It usually costs money. It’s tricky to install correctly. It’s a pain to update “

25

Science and Information / Super Battery Charges to 70% in Just 2 Minutes

« on: November 25, 2014, 02:17:18 PM »

Reference: http://www.technotification.com/2014/10/super-battery-charges-to-70-in-just-2-minutes.html

A team of researchers in Singapore have developed a next generation lithium-ion battery that can recharge a battery to 70-percent in just two minutes. That means it would charge an entire electric car in just 15 minutes. And here’s the kicker: it lasts over 20 years. Normally, it’s safe to be skeptical about new battery technology, but there’s something rather hopeful about this breakthrough.

The new battery isn’t altogether new. It’s actually just an improvement upon existing lithium-ion technology. The key comes in the form of nano-structures. Instead of the traditional graphite used to create the lithium-ion battery’s anode, this new technology uses a cheap titanium dioxide gel, the same kind of material used in sunscreen to absorb UV rays. The scientists found a way to turn the compound into nano-structures that speed up the charging process. And speed it up they do. This simple innovation makes lithium-ion batteries charge 20-times faster and last 20-times longer.

Specifically, the researchers from Nanyang Technological University, claim this new battery technology has a whopping 10,000-cycle lifespan, meaning you can charge a battery 10,000 times before its max charge starts to reduce.

There’s no definite timetable for when upgraded batteries could reach shipping products, but the mini titanium tubes are both easy to make and relatively inexpensive. They could make a big impact on the technology world when they arrive, though. On a basic level, they could eliminate forced obsolescence for some devices — you might only replace them when they no longer meet your needs, not because they can’t hold a charge. They could have a particularly large impact on electric cars — you could top up your battery in minutes, not hours, and avoid replacing a very expensive component before you’re ready to replace the vehicle itself.

NTU associate professor Chen Xiaodong, the inventor of the titanium dioxide gel, says batteries built with it could hit the market within two years, with an unnamed company already licensing the technology. The Nanyang Technology University press release has more detail about the technical aspects of the discovery

26

Science and Information / Soon Flash Memories Will Come In Molecular Size

« on: November 25, 2014, 02:04:06 PM »

Reference: http://www.technotification.com/2014/11/soon-flash-memories-will-come-in-molecular-size.html

It has always the requirement is to have a large amount of storage space available in a drive which itself occupies less space. But recently a milestone has been achieved in this context. Scientists have been successful in their attempts to store data on a single molecule. This accomplishment has been made by a team of international researches who have integrated flash memory on a single molecule. To say, a single molecule, is a little bit of exaggeration. The whole concept is based on three molecules. Surprisingly the storage is based on the electrons, the other two molecules hole precisely these electrons. These two molecules reside inside a metal oxide molecular cage which is just a nano-meter wide in dimension. The metal used in this experiment is tungsten from which the metal cage was made and the selenium tri-oxide molecules are used for holding the storage space electrons.

This technology is not going to appear in the market anytime soon. At the current moment, this research is just a prototype and has many improvements to come. Currently its practical applications are seeming a bit far- fetched. The second major factor to be kept in mind was its volatility. It is very important to ensure for how long this technique will be able to store data in the molecules. The researchers observed that the data could be stored for 336 hours successfully. But it did not last longer than that. The memory drives now able in the market not only ensure durability and security but they also provide standard data transfer rates. If this technology ever hits the market, It will have to improvise upon it data transfer functionality. Researchers say they can theoretically bring those speeds down to pico-seconds or less.

The basic logic behind this technology is that when the two electron are removed from the structure, selenium tri-oxide molecule forms a bond with them. This in turn, creates a single molecule of Se2O6. In this process the charges are exchanged with the metal oxide cage. The molecule, this formed is stable up to very high temperature of about 600 degrees Celsius. This implies that it can be used with a variety of processing methods. To check the working of this setup the researchers coated a wire with a single layer of the caged molecules. They were able to conclude from the experiment that the resulting device could be injected with charges by applying a large negative voltage. If a smaller voltage is applied the presence of electrons could be read out. And with the application of large positive voltage the device will set to its original state.

27

Science and Information / Top 10 Free PC Programs Everyone Should Have

« on: November 09, 2014, 10:42:48 AM »

Reference: http://www.technosensations.com/2014/11/top-10-free-pc-programs-everyone-should.html

list:
1.Antivirus And Malware Protection
2. Backup Solutions (Online backup solution: Mozy or Dropbox)
3. Browsers
4. Compression Utility (Win Zip)
5.Disc Ripper And Creation Utility ( CDBurnerXP)
6.E-Mail
7. FTP, SFTP, And SSH Utility (Filezilla,  MobaXterm, Putty)
8. Image Editor, Paint Program, And Picture Organizer (GIMP,  Paint.net, Google Picasa)
9.Multimedia (Audacity, VLC and MPC-HC)
10. Office Suite (Notepad++ )

28

Science and Information / Harvesting energy from walking around: Shoe insole charges AAA and watch battery

« on: September 30, 2014, 09:48:14 PM »

Collected: http://www.sciencedaily.com/releases/2014/09/140929105239.htm

A shoe fits a device that saves the energy the person makes by walking and successfully uses it in watch batteries.
At the Center for Research in Advanced Materials (CIMAV), scientists decided to "capture" the energy produced by people walking. They designed a pill-shaped cylinder adapted to a shoe in order to store the mechanical-vibrational energy the person generates when walking.
With the captured energy they have been able to recharge clock and AAA batteries. The prototype designed by CIMAV in Chihuahua, in the north of Mexico, adapted the 'pill' which has a diameter of two inches and a thickness of three millimeters to the sole of a shoe.
Abel Macias Hurtado, head of research and specialist in materials science, said that the pill is a device called piezoelectric measuring pressure, force and acceleration, placed in the sole, and by means of a circuit converts mechanical energy into microwatts ; once connected to the batteries, it was tested with good results.
Piezoelectric is a term that comes from pressure and electricity. When walking, mechanical force is generated which is "captured or harvested" to generate the energy that is "stored" in the pill for further use.
The specialist indicates that in the area of ​​nanostructured materials an important base of the research is to harvest or produce clean energy, and this prototype is ideal for that purpose.
"We want to improve the circuit of the tablet to make it more efficient at capturing energy. Now we are working in making it more efficient, currently we already have clean energy," says the researcher at CIMAV.
Hurtado Macias indicates that the prototype was implemented in an ordinary shoe with a wide sole; while walking people steps and makes contact with the ground. That's where the energy is generated.
In this work engineering physics students of the Autonomous University of Chihuahua and Jesus Gonzalez collaborated for the evaluation of results.
Under the same premise, Hurtado Macias been proposed that although a pair of shoes can generate power for the operation of a battery, he considers to adapt a similar system on a "mat" and place it on the entry of a mass transport system like the subway. There it could generate energy capable of illuminating the public transport stations.
"Today, the energy generated by people walking is wasted; if we learn to harvest it and turn it into electricity, we can contribute to the global impact.

29

Science and Information / A Key factor for wireless power transfer

« on: September 30, 2014, 09:13:54 PM »

Reference: http://www.sciencedaily.com/releases/2013/07/130731122512.htm  (collected)

A team of researchers discovered that resonance frequency matching, alignment of the magnetic field, and impedance matching are the most important factors for efficient wireless power transfer. These findings are highly significant, because one futuristic application of wireless power transfer would be to harness and use it via magnetic resonance to charge electric vehicles.
Corresponding coils attached to the bottom of an electric vehicle would pick up energy as the vehicle passes over the coils embedded in the highway. With this type of dynamic charging, an electric vehicle's driving range could become unlimited and the size of its batteries would be greatly reduced.
Wireless power transfer technology may find use in a wide range of applications beyond powering electric vehicles, said Xiaofang Yu, an electrical engineer and postdoctoral fellow at Stanford University who led the research.
Other applications may include charging mobile devices, home appliances, or even medical devices implanted in the human body.

30

Science and Information / Increasing the Optical fiber data throughput by new technology of jigsaw puzzle

« on: September 30, 2014, 08:45:18 PM »

Reference: http://www.sciencedaily.com/releases/2013/12/131204091423.htm (collected)

Optical fibers carry data in the form of pulses of light over distances of thousands of miles at amazing speeds. However, their capacity is limited, because the pulses of light need to be lined up one after the other in the fiber with a minimum distance between them so the signals don't interfere with each other. This leaves unused empty space for data in the fiber.
EPFL's Camille Brès and Luc Thévenaz have come up with a method for fitting pulses together within the fibers, thereby reducing the space between pulses.This opens the door to a ten-fold increase in throughput in our telecommunications systems.
Traffic problems on the information superhighway:
In modern telecommunications exchanges, for example when two cell-phones are communicating with each other, the data are transported between the two antennae on optical fibers, by means of a series of light pulses that form codes.
Simply put, an "on" pulse corresponds to the number 1, while an "off" pulse corresponds to 0. The messages are thus sets of ones and zeros. These codes are decoded by the receiver, providing the initial message. The problem with this system is that the volume of data transmitted at one time can't be increased. If the pulses get too close together, they no longer deliver the data reliably. "There needs to be a certain distance between each pulse, so they don't interfere with each other," says Luc Thevenaz, of EPFL's Fiber Optics Group (GFO). However, the EPFL team noticed that changes in the shape of the pulses could limit the interference.
Pulses that fit together like a jigsaw puzzle:
Their breakthrough is based on a method that can produce what are known as "Nyquist sinc pulses" almost perfectly. "These pulses have a shape that's more pointed, making it possible to fit them together, a little bit like the pieces of a jigsaw puzzle lock together," says Camille Brès. "There is of course some interference, but not at the locations where we actually read the data."
The first to "solve" the puzzle:
The idea of putting pulses together like a puzzle to boost optic fibers' throughput isn't new. However, the "puzzle" had never been "solved" before: despite attempts using sophisticated and costly infrastructures, nobody had managed to make it work accurately enough -- until now. The EPFL team used a simple laser and modulator to generate a pulse that is more than 99% perfect.
The technology is already mature:
The new pulses could well generate interest among many telecommunications-industry market participants. The technology is already mature, as well as 100% optic and relatively cheap. In addition, it appears that it could fit on a simple chip.