Seed, Noise and undoing pseudorandomization

  • Thread starter AtlasSniperma
  • Start date
  • Tags
    Noise Seed
In summary, the conversation discusses the possibility of reversing the process of generating pseudorandom numbers in order to determine the seed used. While it is theoretically possible, it becomes impractical in practice due to the length of the period of the pseudorandom number generator. Various implementations of the generator have different periods, but none of them are considered cryptographically sound. A discussion on this topic can be found on Reddit. The speaker admits to not being able to crack the data stream without prior knowledge.
  • #1
AtlasSniperma
22
0
Okay, title doesn't give a lot of information so please bear with me here.

Forget the why, I just need to figure out how.

I would like, given an array of floats(such as those that would be generated by perlin noise) to be able to extract what seed would be used to generate said set of numbers. I only think this is possible because perlin noise uses pseudorandom number generation, and I assume since pseudorandom numbers are generated from a seed and a process it should be possible to reverse the process.

However I understand if such a prospect is just not possible with the way modern computing works.
Thank you for your time.
 
Technology news on Phys.org
  • #2
In theory, yes. You can reverse engineer the output of a PRNG if you have a large sample, generally one which is larger than the cycle (period of the PRNG).
In practice if the period of the PRNG is long enough, it becomes impractical to execute. rand() as implemented by the Knuth algorithm with RAND_MAX=32767 (on Solaris 10) has a very short period. GNU C (Linux) has a period for rand of 2147483647. Neither version is considered cryptographically sound, AFAIK.

Here is a discussion on a not technical level.
https://www.reddit.com/r/askscience/comments/m6c5d/can_pseudo_randomly_generated_numbers_be_reverse/

To answer your question - I do not know to crack your data stream a priori.
 

1. What is the purpose of using a seed in generating pseudorandom numbers?

The seed is used to initialize the pseudorandom number generator, which ensures that the same sequence of numbers is produced each time the seed is used. This is helpful for replicating experiments and for creating reproducible results.

2. How does noise affect the randomness of pseudorandom numbers?

Noise is a random variation in the signal or data, and it can affect the randomness of pseudorandom numbers by adding an unpredictable element. However, with a good pseudorandom number generator, the noise should not significantly impact the overall randomness of the numbers.

3. How can you ensure that pseudorandom numbers are truly random?

Pseudorandom numbers are not truly random, as they are generated using a mathematical algorithm. However, by using a good quality algorithm and a large enough seed, the sequence of numbers can appear to be random and pass statistical tests for randomness.

4. What is the purpose of undoing pseudorandomization?

Undoing pseudorandomization involves reversing the process of generating pseudorandom numbers to retrieve the original data. This can be useful in cases where the original data is needed, such as in encryption or data compression.

5. Can pseudorandom numbers be used for cryptography?

While pseudorandom numbers can be used for some aspects of cryptography, they are not considered secure enough for creating encryption keys or for other sensitive cryptographic processes. True randomness, such as that from random number generators based on physical phenomena, is preferred for cryptography.

Similar threads

  • Programming and Computer Science
Replies
21
Views
3K
Replies
25
Views
3K
  • Engineering and Comp Sci Homework Help
Replies
2
Views
857
Replies
9
Views
1K
  • Programming and Computer Science
Replies
14
Views
2K
  • Programming and Computer Science
Replies
30
Views
4K
  • Programming and Computer Science
Replies
3
Views
857
  • Programming and Computer Science
Replies
23
Views
1K
Replies
3
Views
2K
  • Programming and Computer Science
Replies
11
Views
997
Back
Top