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Old 05-27-2013, 10:16 PM   #16
ntubski
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Quote:
Originally Posted by jefro View Post
Remember when pgp was in trouble for being uncrackable until the US cracked it.
No, do you have some references to that? Anyway, theoretically uncrackable encryption doesn't mean you automagically have a 100% secure system, the cryptography is only a small part of it.
 
Old 05-27-2013, 10:42 PM   #17
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The intended "Catch-22s" of the one-time pad ... which is, after all, a theoretical system ... are these:
  1. The totally-random key must somehow be conveyed to the intended recipient and to the intended sender, and none other, by some presumably über-secret means. [i]"But if you had that magic-carpet, why not just send the message that way?"
  2. If anyone, by any means (say, a .45 in your gut) ever obtains the "secret" key, he can impersonate you.
  3. If you ever run out of key, you can't send messages anymore. A replacement key can never be "sent to you."

What's a practical cryptosystem? How about VPN, or "https?" Completely transparent to both authorized-sender and authorized-recipient, yet a more than sufficient deterrent to "Eve" (unless she works for one of those secret agencies with three-letter acronyms).
 
Old 09-01-2013, 04:36 AM   #18
H_TeXMeX_H
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Quote:
Originally Posted by 273 View Post
Mathematics proves you wrong:
http://en.wikipedia.org/wiki/Quantum_key_distribution
http://en.wikipedia.org/wiki/One_time_pad
Of course, we tend to trade security for convenience but there's no need to say one has to.
Also see:
http://news.sciencemag.org/physics/2...phy-safe-again

Note that quantum key distribution is just a way to distribute a key for an encryption algorithm. Not only can the key be intercepted, but the encryption is only as strong as the algorithm +- potential backdoors for the NSA.

I don't see how this solves absolutely anything. I think they just like the sound of "quantum", something mysterious, poorly understood, and wildly random and chaotic. Really it's just an attempt at using polarized photons to send keys out in the open. I bet if they called it "polarized photon plaintext key distribution", nobody would ever speak of it again.
 
Old 09-01-2013, 09:15 AM   #19
273
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Quote:
Originally Posted by H_TeXMeX_H View Post
Also see:
http://news.sciencemag.org/physics/2...phy-safe-again

Note that quantum key distribution is just a way to distribute a key for an encryption algorithm. Not only can the key be intercepted, but the encryption is only as strong as the algorithm +- potential backdoors for the NSA.

I don't see how this solves absolutely anything. I think they just like the sound of "quantum", something mysterious, poorly understood, and wildly random and chaotic. Really it's just an attempt at using polarized photons to send keys out in the open. I bet if they called it "polarized photon plaintext key distribution", nobody would ever speak of it again.
Yes, it's as method of key distribution. Once you can securely trade keys if those keys are a one-time-pad then you've got uncrackable encryption. The NSA can't decrypt a one-time-pad because it is impossible.
True, if you buy your key-exchange apparatus off the shelf then, perhaps, somebody made it somehow compromised but with an open specification the key exchange method can be verified and any back doors found.
If you just want an uncrackable encryption scheme right now to use with your own data you can find a true RNG and put a load of bits onto a hard drive and use that as a one-time-pad and you're golden. This is how uncrackable encryption has been done in the past and will continue to be done in the future. It's not some unattainable, magical goal just so expensive and cumbersome that most people do something else.
 
Old 09-01-2013, 11:29 AM   #20
H_TeXMeX_H
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Quote:
Originally Posted by 273 View Post
Yes, it's as method of key distribution. Once you can securely trade keys if those keys are a one-time-pad then you've got uncrackable encryption. The NSA can't decrypt a one-time-pad because it is impossible.
True, if you buy your key-exchange apparatus off the shelf then, perhaps, somebody made it somehow compromised but with an open specification the key exchange method can be verified and any back doors found.
If you just want an uncrackable encryption scheme right now to use with your own data you can find a true RNG and put a load of bits onto a hard drive and use that as a one-time-pad and you're golden. This is how uncrackable encryption has been done in the past and will continue to be done in the future. It's not some unattainable, magical goal just so expensive and cumbersome that most people do something else.
You can't really buy it off the shelf because you need a fiber optic cable to do it.

A TRNG is difficult to find. I'm current trying to build one from various cheap parts, maybe patent it and sell it.

The computer itself is not secure, so if someone has a backdoor into your computer, the one-time-pad is not secure running on this computer.
 
Old 09-01-2013, 11:42 AM   #21
273
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As I understand it there are people who will sell you a quantum encryption setup and no-doubt there are a good many struggling PHDs who would help you verify it for a fee.
I'm not suggesting that absolute security can be attained but simply stating that the encryption side of things is a solved problem and everything going on now is to make things more convenient, cheaper, or avoid the most common avenues of local attack also. Absolutely secure encryption can and, indeed, does exist and is in use.
 
Old 09-05-2013, 01:04 PM   #22
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Quote:
Originally Posted by jefro View Post
I don't believe in uncrackable encryption.
True but that doesn't mean there can't be useful encryption in place that would take too much time to decrypt and by the time it would be cracked..contents wouldn't matter anymore since new ones would be more important and up2date.
 
  


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