Encryption Using Chaos

--- begin forwarded text Date: Fri, 27 Jan 2006 19:10:42 -0500 To: Philodox Clips List From: "R. A. Hettinga" Subject: Encryption Using Chaos http://online.wsj.com/article_print/SB113838965445358466.html The Wall Street Journal January 27, 2006 3:20 p.m. EST MIT TECHNOLOGY REVIEW Encryption Using Chaos Lasers that "hide" messages could mean more foolproof security in online transactions By KATE GREENE January 27, 2006 3:20 p.m. You know that eBay Inc. purchase you made? The online credit card payment you sent? The bank statement you checked at your computer? These transactions contained sensitive information about you that, for the most part, is kept private thanks to encryption software that scrambles the message before it's sent (and unscrambles it once it's received by the intended party). But software is not the only way to protect digital information. Now researchers are looking at ways to exploit lasers with chaotically fluctuating signals, to add an extra layer of privacy to messages sent over fiber-optic lines. By slipping a message into such a laser beam, decrypting the message requires a nearly identical laser to receive it -- a process that's not readily accessible to most people. To demonstrate the feasibility of the technology, Claudio Mirasso of the Universitat de les Illes Balears in Palma de Mallorca, Spain, and his team recently showed that chaotic lasers can send and receive a message over about 75 miles of commercially laid fiber optics. Even more impressive: The transmission rate was one gigabyte of chaos-encrypted information per second -- comparable to that of most commercial data transmissions. It was a major step that, for the first time, put this exotic encryption technique into the real world. 1 Also in MIT Technology Review (www.technologyreview.com2) * Moore's Law Lives * Solar-Powered Nanomotors * Finding Land Mines Faster In order to send a message within a chaotic beam of light, Mr. Mirasso explains, the message must first be converted into an optical signal. It is then fed into a laser that passes it along within the laser's beam. The researchers then heighten the naturally occurring chaos in the beam and feed the message into it. This message-plus-chaos is sent to a nearly identical laser that receives it within its lasing cavity -- the innards of a laser where photons are stimulated and emitted. At this point, Mr. Mirasso says, a phenomenon called chaotic synchronization takes over. This process, admittedly not entirely understood by scientists, makes the receiving laser's output match the message-plus-chaos of the sending laser. Then, to decrypt the original message, the chaos -- a known signal from the sending laser -- is subtracted from the receiving laser's beam, revealing the hidden information. Before chaotic message encryption hits the big time, however, it must be shown to be as robust as traditional optical signals. In the Jan. 1 issue of IEEE Photonic Technology Letters, a group has announced that they've tested the mettle of a chaos-encrypted message by relaying it through an intermediary laser. This step is crucial, explains Alan Shore of the University of Wales in Bangor, because commercial systems use relay stations to boost the distance a message can travel, and chaos-encrypted messages need to be just as strong as other information sent through a network. Mr. Shore's research also shows that it is possible to "send out messages to more than one receiver and extract messages at an intermediary stage," a common occurrence in standard optical networks. Mr. Mirasso's next project involves developing "compact devices for chaos-based optical communication." Still, he notes, some issues with the technology need to be addressed. For instance, researchers still need to quantify the level of security they can offer "compared to other [techniques] like software-based encryption or quantum cryptography," he says. Mr. Mirasso estimates that using lasers to keep information private is roughly five years away from commercial viability. This article appeared Jan. 24, 2006 on the Web site of Technology Review, an MIT Enterprise. -- ----------------- R. A. Hettinga The Internet Bearer Underwriting Corporation http://www.ibuc.com/ 44 Farquhar Street, Boston, MA 02131 USA "... however it may deserve respect for its usefulness and antiquity, [predicting the end of the world] has not been found agreeable to experience." -- Edward Gibbon, 'Decline and Fall of the Roman Empire' --- end forwarded text -- ----------------- R. A. Hettinga The Internet Bearer Underwriting Corporation http://www.ibuc.com/ 44 Farquhar Street, Boston, MA 02131 USA "... however it may deserve respect for its usefulness and antiquity, [predicting the end of the world] has not been found agreeable to experience." -- Edward Gibbon, 'Decline and Fall of the Roman Empire'