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15

I do worry, but not for the resistance of SHA-3; I worry for its acceptance. Technically, what NIST wants to do is sound. They do want to somehow "break" a traditional rule, which is that a hash function with an output of n bits ought to resist collisions with strength 2n/2, and preimages (first and second) with strength 2n. Instead, NIST wants harmonized ...


11

There does appear to be some confusion with point 1. The confusion probably stems from the fact that Keccak has an output size number and a capacity. Output size has little to no effect on security strength. Capacity is what really determines the security strength. So when the post says NIST will only standardize two security levels it is correct (as far as ...


11

I'd say that the whole argument hinges around a "secret attack" that possibly the NSA may know of, enabling them to break some instances of elliptic curves that the rest of the World considers as safe, because the secret attack is, well, secret. This yields to the only possible answer to your question: since secret attacks are secret, they are not known to ...


10

This closure is a rather stupid thing, because the Web site is not closed: indeed, there still is a machine, somewhere, which responds to HTTP requests and returns the "we are closed" page. It would have cost zero effort, and zero extra money, to simply let the Web site run and keep on serving PDF files. For crypto development, this means that until the US ...


7

I would characterize the service as similar to a trusted time-stamping service. Except they do not do the time-stamping, but just provide the "key". This allows a user to decide what do to with it, such as using it as a private key to sign something, or an HMAC key, proving the signature is "not older" than the timestamp. If the signature is published to a ...


7

The answer is yes, non-US ciphers exist and are in fact very popular. Actually, some who are looking for alternatives, opt for non-NSA/NIST ciphers, for instance Salsa/ChaCha from DJB (who is US citizen). A lot of ciphers have been developed in EU and Japan. China definitely has developed ciphers for its own use, just like many other countries. But long ...


7

With any $n$ bit hash it is possible to: Find preimages with work $2^n$ on classical computers and $2^{n/2}$ using quantum computers Find collisions with work $2^{n/2}$ on classical computers and $2^{n/3}$ using quantum computers I want to emphasize that these are generic attacks that always work, no matter which concrete hashfunction is used. Grover's ...


7

As an Iranian Cryptology student in one of the most well-known Iranian Universities called Sharif University of Technology, I want to add this to the answers. There doesn't seem to be any National Standard Cipher here in Iran. But It doesn't mean that there shouldn't be any classified cipher being used by the military or the revolutionary guards. As I am ...


6

Plenty of ciphers come out of the USA from government research or selection competitions. AES and DES are examples. Indeed, the US is known from some crypto-related competitions that were/are ope to anyone and they surely will do ample of government research related to cyptology, but you need to be sure that you differ between “they selected it” and ...


6

Reading the CHES'13 presentation by John Kelsey does make things clearer. Basically, the whole thing (with the output lengths and capacities) seems to come down to the fact that NIST wants to standardize two versions of the underlying sponge function, SHAKE256 and SHAKE512, with respective capacities of 256 and 512 bits, and then define the actual SHA3 hash ...


6

This has been basically asked already: Should we trust the NIST recommended ECC parameters? History Once it was found that NSA allegedly had inserted backdoor to a cryptographic standard, people started thinking what standard it was. The most common guess is that the Dual EC DRBG is the backdoored standard. However, some amount of (possibly justified) ...


5

No they did not, the internals and security levels have not been changed from the draft Keccak submission, only the padding rule has changed. The padding change is the only difference, this allows future tree hashing modes as well as the current SHAKE outputs to generate different digests given the same security parameters and message inputs. Up to 4 ...


4

You are using the wrong value as the modulus; you ought to be using the value $r$ (which is also listed in the document). $p$ is the characteristic of the field that the elliptic curve you're using is defined on. In this case, we're not interested in that; instead what we're interested in is the order of the curve, that is, that value $r$ such that $rP = ...


3

The routine you link to is already performing that check (lines 15-17): it returns $(0,0,0)$ when $S$ and $T$ are equal, and the caller is expected to handle this by calling the doubling routine. The equality verification is performed by checking whether $$X_1Z_2^2 - X_2Z_1^2 = 0$$ $$Y_1Z_2^3 - Y_2Z_1^3 = 0$$ It is easy to see that, since $x = X/Z^2$ ...


3

I wonder why anyone would choose to rely on a source of true random numbers fraught with questions that will ultimately have no provable - or perhaps even satisfactory - answer. There are at least a couple of companies that sell generators that provide high quality true random numbers. Having a generator on-site and available real-time allows the necessary ...


3

PRNGs are a difficult and hot topic. Some tests can be found here: What tests can I do to ensure my PRNG is working correctly? But they do not tell you (or others) if your PRNG is really secure. A PRNG must be build in a way, that a third party is not able to "calculate" former or upcoming PRNG output based on some random data from the PRNG.


3

Yes. The Serpent Cipher was developed outside of America, and isn't maintained by an American group. It came in 2nd place during the AES competition. It has a higher safety factor than AES (Rijndael), but isn't as fast. And there are stream ciphers being developed and validated by eSTREAM in Belgium. The Salsa20 stream cipher, by American cryptographer ...


2

Background When defining protocol compliant with NIST SP 800-108, you just need to pick suitable options, which work well with your protocol. If there is a need to be compatible with a specific pre-existing protocol, you may want to take a look at NIST SP 800-135Rev1, which defines application specific key derivation functions. It is notable to recognize ...


2

I cannot see it having a negative effect, only a positive effect. Let's look at the Reddit AMA of Glenn Greenwald and the relevant comment: There are hundreds of encryption standards compromised by the program the Guardian, NYT and PP all reported on. I have never seen any list of those standards and don't have it. If I did have it, I would publish it ...


2

This closure could have an unintended effect on security. If a researcher was attempting to use a NIST resource, he or she might turn to a third party due to the unavailability of the NIST site. This may spur awareness, interest, or growth in other international standards bodies, such as ISO, or even to form an ECRYPT-III effort. If that third party turns ...


1

First up: Don't believe the hype! Especially if things can easily be proven wrong. What I mean is that your NIST have just launched a new service… is incorrect, as the NIST Randomness Beacon project is known to me (and others) since 2011. Furthermore, this project was awarded a multi-year grant from NIST's Innovations in Measurement Science (IMS) Program in ...



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