Technology Trends

If you use a webcam to talk with your mom, this tool is not for you. But if you’re working for a company and that you have to routinely discuss about sensitive future projects or the possible acquisition of another company, you need more security, and this new video conferencing system based on quantum cryptography is a tool you need. According to this article from Nature, researchers from Toshiba have developed a system which can generate 100 quantum ‘keys’ every second, fast enough to protect every frame in a video exchange. This technology, which today is working over a distance of about 120 kilometers, could become commercially available within two years at an initial cost of $20,000. Read more…

Here is the introduction from Nature.

Scientists from Toshiba’s Cambridge Research Laboratory unveiled their invention to business leaders and government officials at Britain’s Department of Trade and Industry in London on 27 April.

Their system is capable of generating 100 quantum ‘keys’ every second. This is fast enough for every individual frame of video to be protected by its own encryption. “This makes the system highly secure,” says Andrew Shields, who leads the Cambridge team. “It would take an enormous computational resource to crack this frame by frame.”

Of course, today’s videoconferencing tools using conventional encryption are already pretty secure. But if the NSA wants to check your conversation, I bet it can. With quantum cryptography, this is a different story.

Quantum cryptography promises to stop such eavesdroppers. The system works by first establishing a ‘key’ that provides instructions on how to decode an incoming message. This key is built into the quantum state of photons. Intercepting a message breaks the key and alerts the sender and intended recipient to the security breach, because the very act of observing a quantum state changes it.

The Quantum Information Group at Toshiba gives more details on this subject on this page about Security from Eavesdropping. Below is a diagram illustrating the concept (Credit: Toshiba’s Cambridge Research Laboratory).

Using single photons to carry the bit material for the key prevents undetected eavesdropping. Because each bit is carried by a single photon, it is not possible for a hacker to tap in and remove part of the signal, as shown in the illustration. Single photons do not split, so if the hacker (Eve) measures the photons on the fibre, they will not reach the intended recipient (Bob). Only the photons that arrive at Bob are used to form the key, so Eve cannot gain any useful information by this crude ‘tapping’ attack.

The first commercial applications of quantum cryptography are now about one year old. However, this new system offers new levels of performances, according to Nature.

Unlike previous systems, which become unreliable when they heat up, this device can run continuously for more than four weeks, says Shields. The quantum information can only go so far before being corrupted by random interactions with surrounding material, however. “We’ve shown this can work over 120 kilometres of fibre,” says Shields.

Toshiba has already built a Quantum Cryptography Prototype. And the research work has been published by Applied Physics Letters (Vol. 84, Issue 19, Pages 3762-3864, May 10, 2004) under the title “Quantum key distribution over 122 km of standard telecom fiber.” Here is a link to the abstract.

We report a demonstration of quantum key distribution over a standard telecom fiber exceeding 100 km in length. Through careful optimization of the interferometer and single photon detector, we achieve a quantum bit error ratio of 8.9% for a 122 km link, allowing a secure shared key to be formed after error correction and privacy amplification. Key formation rates of up to 1.9 kbit/s are achieved depending upon fiber length. We discuss the factors limiting the maximum fiber length in quantum cryptography.

Finally, here is a link to the full paper (PDF format, 14 pages, 68 KB).

Sources: Mark Peplow, Nature, April 28, 2005; Toshiba’s Cambridge Research Laboratory website

Related stories can be found in the following categories.

• Cryptography
  
  
• Networking
  
  
• Quantum World
  
  
• Security
  

Researchers at Xerox PARC have developed a new way to imbed machine-readable information in printed documents. According to this article from Sci-Tech Today, “Digital Evolution Continues with Xerox Glyphs,” their dataglyphs are composed only of forward (/) or backward () slashes — similar to the zeros and ones used in binary code. These dataglyphs could replace bar codes or be used in faxes, easing the way of routing information in a large company. Xerox is already using these dataglyphs for several projects, including one in Latin America to reduce check fraud. The company also has started an experiment named ‘GlyphSeal’ for two-sided documents, one for human eyes, and the other for machines. Read more…

Here are some quotes from one of the Xerox PARC researchers, Jeff Breidenbach.

“Under a magnifying glass, you can see that a dataglyph is composed of hundreds or thousands of tiny diagonal lines, leaning either forwards or backwards,” said Xerox PARC research scientist Jeff Breidenbach. “Diagonal lines tend to unobtrusively blend — and by varying the color and thickness of these marks, we achieve a lot of aesthetic control.”

“Dataglyphs are essentially a barcode on steroids,” Breidenbach says. “In some ways they are simply more flexible — much more aesthetically flexible, more resistant to certain types of environmental damage, easier to read on curved surfaces, and more flexible in the quantity of data stored — from a handful of bytes to tens of kilobytes.”

You can create and decode your own dataglyphs by running this demonstration.

You’ll find much more information on this technology by reading this technical overview of dataglyphs.

But let’s return to Sci-Tech Today for a description of the ‘GlyphSeal’ experiment ,Breidenbach’s favorite application.

A Xerox experiment, GlyphSeal “is a technique for printing a hybrid analog/digital paper document,” Breidenbach explained. “The front sides of the paper are human readable, while the reverse sides contain a complete machine-readable digital representation. This allows a document to easily travel from computer system to printout and back again.”

The latest research work about GlyphSeal has been published by the Proceedings of SPIE (Volume: 5306, June 2004) under the title “Collocated Dataglyphs for large-message storage and retrieval.” Here is a link to the abstract — a full version in PDF format costs $15. Here is the beginning of the abstract.

In contrast to the security and integrity of electronic files, printed documents are vulnerable to damage and forgery due to their physical nature. Researchers at Palo Alto Research Center utilize DataGlyph technology to render digital characteristics to printed documents, which provides them with the facility of tamper-proof authentication and damage resistance. This DataGlyph document is known as GlyphSeal. Limited DataGlyph carrying capacity per printed page restricted the application of this technology to a domain of graphically simple and small-sized single-paged documents. In this paper the authors design a protocol motivated by techniques from the networking domain and back-up strategies, which extends the GlyphSeal technology to larger-sized, graphically complex, multi-page documents.

Xerox PARC has a long history of good ideas that never been commercially successful — at least for Xerox. Will these dataglyphs become a hit or a flop? Time will tell.

Sources: Mike Martin, Sci-Tech Today, January 21, 2005; and various websites

Related stories can be found in the following categories.

• Cryptography
  
  
• Forensics
  
  
• Innovation
  
  
• Optics
  
  
• WebSites