"Unbreakable" Encryption Almost Certainly Isn't
schneier.com
"Unbreakable" Encryption Almost Certainly Isn't
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Re: "Unbreakable" Encryption Almost Certainly Isn't
#2> The researchers, led by Dr. Tomislav Stankovski, created an encryption mechanism that can generate a truly unlimited number of keys, which they say vastly increases the security of the communication. To do so, they took inspiration from the anatomy of the human body.
Maybe this is just a problem of imprecise language and reporting, but when has the ability to generate an unlimited number of keys ever been the main problem? I always thought the problem was distributing/maintaining such a number of keys, and to a lesser extent, generating those keys in a reasonable amount of time.
Because wasn't "unbreakable" encryption invented a long time ago, and implemented successfully since? That is, one-time pads, which are theoretically unbreakable by anyone who is not omniscient? Of course, the problem of distributing and maintaining such keys gets in the way of popular implementation...
edit: I'm obviously not suggesting that one-time pads have solved much of anything...just that, why do researchers brag about creating an infinite number of keys, or even "unbreakable" encryption, when those don't seem to be much of a real-world problem...Maybe in this case it's just bad reporting and translation of researcher-speak. Now, extremely-unfeasible-to-break while feasible-to-use...that's clearly worth bragging about.
Re: "Unbreakable" Encryption Almost Certainly Isn't
#3> The researchers, led by Dr. Tomislav Stankovski, created an encryption mechanism that can generate a truly unlimited number of keys, which they say vastly increases the security of the communication. To do so, they took inspiration from the anatomy of the human body. Maybe this is just a problem of imprecise language and reporting, but when has the ability to generate an unlimited number of keys ever been the main…
> why do researchers brag about creating an infinite number of keys, or even "unbreakable" encryption,
To generate some funding and impress gullible people? It is like unlimited energy or flying car projects.
Re: "Unbreakable" Encryption Almost Certainly Isn't
#4There's only one "unbreakable" encryption, and that's a pair of one time pads with truly random data as long as the message itself.
http://www.pro-technix.com/information/crypto/pages/vernam_b...
Re: "Unbreakable" Encryption Almost Certainly Isn't
#5> The researchers, led by Dr. Tomislav Stankovski, created an encryption mechanism that can generate a truly unlimited number of keys, which they say vastly increases the security of the communication. To do so, they took inspiration from the anatomy of the human body. Maybe this is just a problem of imprecise language and reporting, but when has the ability to generate an unlimited number of keys ever been the main…
For no encryption scheme is the key space unlimited.
For symmetric key ciphers, the keys are of a set length. AES accepts key lengths of 128, 192, and 256 bits.
For asymmetric ciphers, they vary even more. The RSA-XXXX designation refers to the length of n, which is the product of two primes (which must be kept secret) p and q. So for RSA-2048, p and q are roughly 1024-bit numbers. In addition, the secret exponent can frequently be quite large, although as it's calculated from the public key exponent and n its size is not guaranteed.
Ultimately however, all of these are designed so that the key spaces are too large to be feasibly brute-forced searched. The reason for the much larger size of the keys for the asymmetric ciphers is that their security is usually based on the difficulty of solving a problem (in RSA's case, factoring n into p and q, or the equally difficult problem of determining the totient of n) that gets more difficult as the keys get larger.
EDIT: And yes, one-time pads are theoretically unbreakable, however they can only be used once (as the name implies, but if they are used twice recovering the key is trivial), must rely on a sufficently good quality random number generator (which Matt Green recently had a very good article describing how hard it is to do: http://blog.cryptographyengineering.com/2014/03/how-do-you-k...) and they have the same issues that any symmetric key ciphers have, in terms of key distribution. They're useful when you have old women in Bletchley Park spinning bingo balls and carefully copying into two notebooks. Less so when you're trying to build a usable system for secure communication.
Re: "Unbreakable" Encryption Almost Certainly Isn't
#6There's only one "unbreakable" encryption, and that's a pair of one time pads with truly random data as long as the message itself. http://www.pro-technix.com/information/crypto/pages/vernam_b...
While this may seem like a tempting statement, it is not really an answer, since "unbreakable" is not really well-defined. Clearly, "truly random" is a bit of a tough one to define. And sending the message length is a bit of an information leak itself. But even putting those aside, there's a bigger flaw.
The biggest problem in this mechanism is how does the other party get their one-time pad? An upper bound on the unbreakableness of the entire scheme is the unbreakability of transmitting a one-time pad; and if you can do that, then why not just send the actual message via that mechanism?
Re: "Unbreakable" Encryption Almost Certainly Isn't
#7There's only one "unbreakable" encryption, and that's a pair of one time pads with truly random data as long as the message itself. http://www.pro-technix.com/information/crypto/pages/vernam_b...
And even this is in practice a problem: How do you distribute and secure the pads?
A lot of problems in cryptosystems stem from implementation details - think side-channel attacks, exploits, ...
Re: "Unbreakable" Encryption Almost Certainly Isn't
#8There's only one "unbreakable" encryption, and that's a pair of one time pads with truly random data as long as the message itself. http://www.pro-technix.com/information/crypto/pages/vernam_b...
While this may seem like a tempting statement, it is not really an answer, since "unbreakable" is not really well-defined. Clearly, "truly random" is a bit of a tough one to define. And sending the message length is a bit of an information leak itself. But even putting those aside, there's a bigger flaw. The biggest problem in this mechanism is how does the other party get their one-time pad? An upper bound on the un…
"unbreakable" may be not well-defined, but perfect secrecy is[1].
1. http://en.wikipedia.org/wiki/One-time_pad#Perfect_secrecy
Re: "Unbreakable" Encryption Almost Certainly Isn't
#9I love these two lines from Shneier's earlier article, the one he links to at the end:
"The 'best cryptographers around' break a lot of ciphers. The academic literature is littered with the carcasses of ciphers broken by their analyses."
Re: "Unbreakable" Encryption Almost Certainly Isn't
#10There's only one "unbreakable" encryption, and that's a pair of one time pads with truly random data as long as the message itself. http://www.pro-technix.com/information/crypto/pages/vernam_b...
While this may seem like a tempting statement, it is not really an answer, since "unbreakable" is not really well-defined. Clearly, "truly random" is a bit of a tough one to define. And sending the message length is a bit of an information leak itself. But even putting those aside, there's a bigger flaw. The biggest problem in this mechanism is how does the other party get their one-time pad? An upper bound on the un…
> why not just send the actual message via that mechanism?
suppose you can transmit information securely only for some time. Exchange one time pads ahead of time, and use them later to communicate over insecure channel