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3
votes
1answer
79 views

Do I need a salt when hashing a randomly generated password?

I have passwords stored in my database that are very long, unique and generated by a CSPRNG. Do I need to use a salt before hashing them? My understanding is that usually you use a hash function in ...
0
votes
1answer
48 views

Secure shuffles and the rand() function

I'm trying to understand one aspect of a secure shuffle using Fisher-Yates. For reference, here is Fisher-Yates to shuffle an array x of n elements (numbered from 0 to n-1) (from Securing a Shuffle ...
2
votes
2answers
115 views

Securing a Shuffle Algorithm

After reading about writing a secure shuffle algorithm, I realized that my module that generates a password is only as strong as my PRNG, which in this case is Math.random(). I'm confused as to how to ...
15
votes
3answers
609 views

Why CSRF Token has to be a Cryptographically Strong Random number, in Double Submit Cookies method?

I was just going through the OWASP's Cheat Sheet for CSRF Prevention. In the Double Submit Cookies method, I saw this the site should generate a (cryptographically strong) pseudorandom value ...
3
votes
2answers
119 views

Reliable random seed for RNG

I want to create my computer passwords with a RNG, but I am thinking about one thing: I would use python to write that script and the RNG is controlled by one seed, most likely the time. If I would ...
12
votes
4answers
4k views

Why OpenSSL can't use /dev/random directly?

I couldn't find the answer for the reason anywhere, even the wiki page doesn't explain it. This seems like using a PRNG for seeding an another PRNG. The first one (/dev/random) may itself be seeded by ...
8
votes
4answers
824 views

Does hashing a PRNG make it cryptographically secure?

Would hashing the result of a regular random number generator produce a cryptographically secure PRNG? For example, would sha1(rand()) effectively be a secure PRNG? Assuming it doesn't, how would ...
5
votes
2answers
103 views

Does RNG play a role in PGP signing?

We have a Jenkins system that builds and PGP-signs software releases, and we are considering moving the signing component to an isolated VM instead of running it as part of the overall builder ...
2
votes
3answers
307 views

How secure is to seed PRNGs with the sequences from CSPRNG?

Background: Implementing online casino, I would like to use a number of PRNGs with high throughput, like MersenneTwisterFast. I know it is not cryptographically strong, but quite unpredictable when ...
3
votes
4answers
479 views

What are the features of Dual EC DRBG that are lost when using a different cipher?

Due to a potential NSA backdoor, the NIST is now recommending that implementor no longer use ECC-based PRNG Dual EC DRBG. (As described in Wired.com) this PRNG has certain features such as: ...
2
votes
1answer
713 views

Using Random Numbers As Session variables

I am using randomly generated numbers as session variables to identify the sessions in a PHP application. To make further security proof what ways should I follow?
0
votes
1answer
329 views

Can SHA-1 PRNG still create secure cipher keys?

I am concerned that a SHA-1 PRNG cannot produce an AES-256 cipher key with the expected 256 bits of security, or indeed any secure cipher key where over 165 bits of security are expected. The SHA-1 ...
2
votes
1answer
309 views

What key to use in HMAC

I need to use HMAC on a certain message to guarantee integrity, but I cannot figure out what are the requirements for the key to be given as input to the hashing algorithm. In particular I have to ...
5
votes
1answer
165 views

Detecting PRNG Use from Output

Question: Is there a way to detect the use of a PRNG strictly from observing the output provided by an application? Background: During an audit of a key generating algorithm that I knew was based on ...
3
votes
3answers
329 views

PRNG: Does combining insecure algos help?

Reading about how insecure PHP's rand function is, I was wondering if it helps to combine random functions. The suggested function there, openssl_random_pseudo_bytes, can also be cryptographically ...