Homebrew Cryptography
Nice article about a would-be spy and his homebrew pencil-and-paper cryptography.
Entries Tagged "cryptography"
Page 36 of 55
New Attack on Threefish
At FSE 2010 this week, Dmitry Khovratovich and Ivica Nikolic presented a paper where they cryptanalyze ARX algorithms (algorithms that use only addition, rotation, and exclusive-OR operations): “Rotational Cryptanalysis of ARX.” In the paper, they demonstrate their attack against Threefish. Their attack breaks 39 (out of 72) rounds of Threefish-256 with a complexity of 2252.4, 42 (out of 72) rounds of Threefish-512 with a complexity of 2507, and 43.5 (out of 80) rounds of Threefish-1024 with a complexity of 21014.5. (Yes, that’s over 21000. Don’t laugh; it really is a valid attack, even though it—or any of these others—will never be practical.)
This is excellent work, and represents the best attacks against Threefish to date. (I suspect that the attacks can be extended a few more rounds with some clever cryptanalytic tricks, but no further.) The security of full Threefish isn’t at risk, of course; there’s still plenty of security margin.
We have always stood by the security of Threefish with any set of non-obviously-bad constants. Still, a trivial modification—changing a single constant in the key schedule—dramatically reduces the number of rounds through which this attack can penetrate. If NIST allows another round of tweaks to the SHA-3 candidate algorithms, we will almost certainly take the opportunity to improve Skein’s security; we’ll change this constant to a value that removes the rotational symmetries that this technique exploits. If they don’t, we’re still confident of the security of Threefish and Skein.
And we’re always pleased to see more cryptanalysis against Threefish and Skein.
768-bit Number Factored
News:
On December 12, 2009, we factored the 768-bit, 232-digit number RSA-768 by the number field sieve. The number RSA-768 was taken from the now obsolete RSA Challenge list as a representative 768-bit RSA modulus. This result is a record for factoring general integers. Factoring a 1024-bit RSA modulus would be about a thousand times harder, and a 768-bit RSA modulus is several thousands times harder to factor than a 512-bit one. Because the first factorization of a 512-bit RSA modulus was reported only a decade ago it is not unreasonable to expect that 1024-bit RSA moduli can be factored well within the next decade by an academic effort such as ours…. Thus, it would be prudent to phase out usage of 1024-bit RSA within the next three to four years.
[…]
Our computation required more than 1020 operations. With the equivalent of almost 2000 years of computing on a single core 2.2GHz AMD Opteron, on the order of 267 instructions were carried out. The overall effort is sufficiently low that even for short-term protection of data of little value, 768-bit RSA moduli can no longer be recommended.
FIPS 140-2 Level 2 Certified USB Memory Stick Cracked
Kind of a dumb mistake:
The USB drives in question encrypt the stored data via the practically uncrackable AES 256-bit hardware encryption system. Therefore, the main point of attack for accessing the plain text data stored on the drive is the password entry mechanism. When analysing the relevant Windows program, the SySS security experts found a rather blatant flaw that has quite obviously slipped through testers’ nets. During a successful authorisation procedure the program will, irrespective of the password, always send the same character string to the drive after performing various crypto operations—and this is the case for all USB Flash drives of this type.
Cracking the drives is therefore quite simple. The SySS experts wrote a small tool for the active password entry program’s RAM which always made sure that the appropriate string was sent to the drive, irrespective of the password entered and as a result gained immediate access to all the data on the drive. The vulnerable devices include the Kingston DataTraveler BlackBox, the SanDisk Cruzer Enterprise FIPS Edition and the Verbatim Corporate Secure FIPS Edition.
Nice piece of analysis work.
The article goes on to question the value of the FIPS certification:
The real question, however, remains unanswered how could USB Flash drives that exhibit such a serious security hole be given one of the highest certificates for crypto devices? Even more importantly, perhaps what is the value of a certification that fails to detect such holes?
The problem is that no one really understands what a FIPS 140-2 certification means. Instead, they think something like: “This crypto thingy is certified, so it must be secure.” In fact, FIPS 140-2 Level 2 certification only means that certain good algorithms are used, and that there is some level of tamper resistance and tamper evidence. Marketing departments of security take advantage of this confusion—it’s not only FIPS 140, it’s all the security standards—and encourage their customers to equate conformance to the standard with security.
So when that equivalence is demonstrated to be false, people are surprised.
Quantum Cryptography Cracked
This presentation will show the first experimental implementation of an eavesdropper for quantum cryptosystem. Although quantum cryptography has been proven unconditionally secure, by exploiting physical imperfections (detector vulnerability) we have successfully built an intercept-resend attack and demonstrated eavesdropping under realistic conditions on an installed quantum key distribution line. The actual eavesdropping hardware we have built will be shown during the conference.
While I am very interested in quantum cryptography, I have never been optimistic about its practicality. And it’s always interesting to see provably secure cryptosystems broken.
Al Qaeda Secret Code Broken
I would sure like to know more about this:
Top code-breakers at the Government Communications Headquarters in the United Kingdom have succeeded in breaking the secret language that has allowed imprisoned leaders of al-Qaida to keep in touch with other extremists in U.K. jails as well as 10,000 “sleeper agents” across the islands….
[…]
For six months, the code-breakers worked around the clock deciphering the code the three terrorists created.
Between them, the code-breakers speak all the dialects that form the basis for the code. Several of them have high-value skills in computer technology. The team worked closely with the U.S. National Security Agency and its station at Menwith Hill in the north of England. The identity of the code-breakers is so secret that not even their gender can be revealed.
“Like all good codes, the one they broke depended on substituting words, numbers or symbols for plain text. A single symbol could represent an idea or an entire message,” said an intelligence source.
The code the terrorists devised consists of words chosen from no fewer than 20 dialects from Afghanistan, Iran, Pakistan, Yemen and Sudan.
Inserted with the words either before or after them is local slang. The completed message is then buried in Islamic religious tracts.
EDITED TO ADD: Here’s a link to the story that still works. I didn’t realize this came from WorldNetDaily, so take it with an appropriate amount of salt.
Blowfish in Fiction
The algorithm is mentioned in Von Neumann’s War, by John Ringo and Travis Taylor.
P. 495:
The guy was using a fairly simple buffer overflow attack but with a very nice little fillip of an encryption packet designed to overcome Blowfish. The point seemed to be to create a zero day exploit, which he didn’t have a chance of managing. So far, nobody had cracked Blowfish.
P. 504:
As far as he could tell, at first, it was a simple Denial of Service attack. A DoS occurred when… But this one was different. Every single packet contained some sort of cracking program … Most had dumped to the honey trap, but they were running rampant through there, while others had managed to hammer past two firewalls and were getting to his final line of defense. Somebody had managed a zero day exploit on Blowfish. And more were coming in!
The Doghouse: Privacy Inside
I’m just going to quote without comment:
About the file:
the text message file encrypted with a symmetric key combine 3 modes1st changing the original text with random (white noise) and PHR (Pure Human Randomness) shuffle command , move and replace instruction combine with the key from mode 1 (white noise) and 2 (PHR)
2nd mode xor PHR – Pure Human random ( or ROEE Random Oriented Enhanced Encryption) with a TIME set of instruction , and a computational temporary set of instructions to produce a real one time PAD when every time ,
Text will transform to a cipher the last will be different
3rd mode xor WNS – White Noise Signal with a TIME set of instruction , and a computational temporary set of instructions to produce a real one time PAD when every time ,
Text will transform to a cipher the last will be different
4th Reconstructs file, levels and dimensions to a
this is a none mathematical with zero use of calculation algorithm – so no brute force , Rainbow Crack , or gpu cuda nvidia brute force crack can be applied on this technology . Sorry you have to find a new way to crack chaos theory for that.We use 0% of any mathematical calculation algorithm so we can perform any ware with unparalleled strength
Key Strength – 1million bit or more
Speed performance 400% faster Compeer to AES
MPU use – Mathematical Process Unit in CPU use 3% – 7% only
Overhead of the file from original 5% +/- (original+5%) +/-
A combination of mode 1 and 2 applied with a new variation of XOR – to perform the encrypted message
Anyone have any ideas?
Sidebar photo of Bruce Schneier by Joe MacInnis.