From: the physics arXiv blog <[EMAIL PROTECTED]> Subject: the physics arXiv blog To: [EMAIL PROTECTED] Date: Fri, 05 Dec 2008 13:10:50 +0000
[1]the physics arXiv blog [2]Quantum direct communication: secrecy without key distribution Posted: 04 Dec 2008 09:13 PM PST [3]quantum-direct-communication.jpg An interesting development in the world of quantum encryption. In the last couple of years, we've seen a number of quantum key distribution systems being set up that boast close-to-perfect security ([4]although they're not as secure as the marketing might imply). These systems rely on two-part security. The first is the quantum part which reveals whether a message has been intercepted or not. Obviously this is no use when it comes to sending secret message because it can only uncover eavesdroppers after the fact. So Alice sends a one time pad over this quantum channel that she and Bob can later use to encrypt and send a message classically. If this key is compromised, Alice sends another. What guarantees the security is not quantum mechanics but the second part of the system: the one time pad. Today, Seth Lloyd and colleagues at the Massachusetts Institute of Technology in Cambridge, publish a way of guaranteeing security over a quantum channel without having to fall back on a one time pad. Their idea is to send a message over a standard quantum channel without bothering with a one time pad. The security, they say, can be monitored by randomly checking the channel to see whether any of the qubits are being lost (potentially to Eve). The security of the channel then depends on how much loss of information Alice and Bob are willing to accept, but can always be improved by checking more often for eavesdroppers. Quantum direct communication, as the team call it, looks interesting. But it will be demanding to implement, not least because any noise in the channel will look like an eavesdropper. So it looks as if this idea will have to be limited to short range applications where noise can be kept to a minimum. Nevertheless, a cool idea. Ref: [5]arxiv.org/abs/0802.0656: Quantum Direct Communication with Continuous Variables [6][ISMAP:i] [7][arXivblog?d=41] [8][arXivblog?d=43] [9][arXivblog?i=FkCcdrzA] [10][arXivblog?d=50] [11][arXivblog?i=AA6d3u4X] [12][arXivblog?d=54] [13][arXivblog?i=gWxiPcYK] [14][arXivblog?d=52] You are subscribed to email updates from [15]the physics arXiv blog To stop receiving these emails, you may [16]unsubscribe now. Email delivery powered by Google Inbox too full? [17](feed) [18]Subscribe to the feed version of the physics arXiv blog in a feed reader. If you prefer to unsubscribe via postal mail, write to: the physics arXiv blog, c/o Google, 20 W Kinzie, Chicago IL USA 60610 References 1. http://arxivblog.com/ 2. http://feedproxy.google.com/~r/arXivblog/~3/L2dvPUasU7A/ 3. http://arxivblog.com/wp-content/uploads/2008/12/quantum-direct-communication.jpg 4. http://arxivblog.com/?p=637 5. http://arxiv.org/abs/0802.0656 6. https://feedads.googleadservices.com/~a/i7RRFcowUHJnq_spRFzOodIFPIY/a 7. http://feedproxy.google.com/~f/arXivblog?a=HIgKcQ0O 8. http://feedproxy.google.com/~f/arXivblog?a=bO8lGfma 9. http://feedproxy.google.com/~f/arXivblog?a=FkCcdrzA 10. http://feedproxy.google.com/~f/arXivblog?a=ybFs1PaM 11. http://feedproxy.google.com/~f/arXivblog?a=AA6d3u4X 12. http://feedproxy.google.com/~f/arXivblog?a=sdxB9J6P 13. http://feedproxy.google.com/~f/arXivblog?a=gWxiPcYK 14. http://feedproxy.google.com/~f/arXivblog?a=rqQMNiZh 15. http://arxivblog.com/ 16. http://feedburner.google.com/fb/a/mailunsubscribe?k=118r9-S4Z0vJg-AkQPASPmDmlGQ 17. http://feedproxy.google.com/arXivblog 18. http://feedproxy.google.com/arXivblog ---------- -- Eugen* Leitl <a href="http://leitl.org">leitl</a> http://leitl.org ______________________________________________________________ ICBM: 48.07100, 11.36820 http://www.ativel.com http://postbiota.org 8B29F6BE: 099D 78BA 2FD3 B014 B08A 7779 75B0 2443 8B29 F6BE --------------------------------------------------------------------- The Cryptography Mailing List Unsubscribe by sending "unsubscribe cryptography" to [EMAIL PROTECTED]