Reading assignment: Hashing

[Lurkur]

1. SHA-256
2. there are too many possible answers in a long string of characters for anyone to correctly guess.

[thoth]

1. SHA 256
2. very large set of outcomes

[carolb]

• What is the hashing algorithm called used in Bitcoin?
  A) SHA 256 (secure hashing algorithm 256)

• Why is this hashing algorithm really hard (almost impossible) to brute-force?
  A) you, your children, your children’s children… could spend everyday/night trying to figure it out.
  The mathematical probability of figuring it out is astronomical, it doesn’t matter.

[acf]

1. SHA-256

2. It is infeasible to use brute-force as it will take an unrealistically long time in a person’s lifetime to crack open; given the high amount of possibilities for the correct hash correlating to the high amount of input values needed to be assessed per hash in the bitcoin blockchain.

[igenew]

1. What is the hashing algorithm called used in Bitcoin?
   It is called Secure Hashing Algorithm 256, SHA-256.

2. Why is this hashing algorithm really hard (almost impossible) to brute-force?
   The hashing algorithm takes specific information of any length computes it and outputs a unique 256 hash.
   If any of the characters within that specific data is changed or altered the algorithm hash will be different.

[paddyc1]

1. The hashing algorithm used in Bitcoin is called SHA-256.

2. It is almost impossible to brute-force the hashing algorithm because the probability of successfully guessing is too low.

[conwayddd]

1. sha-256
2. The algorithm is almost impossible to brute force because there are so many possible inputs. It would take way too long to guess the correct input using the brute force method, which is the only possible method.

[J.C]

1. The hashing algorithm is called SHA-256
2. Simply put it will take you a long time till you even find the answer with the brute force method, which makes it non-efficient.

[ivleague]

1. SHA-256 Algorithm

2. The SHA-256 Algorithm is difficult to brute force because you can’t reverse the hash to it’s original form, it’s to verify that the contents of the input haven’t been changed and not to encrypt a message for someone to be decrypted later on.

[Iggiepop]

1. SHA 256
2. To be able to brute force the algorithm you would have to try 2^256 times which would take more than an average lifetime to achieve.

[Alko89]

@ivleague

encrypt a message for someone to be decrypted later on.

Hash functions are not really used for encryption, you can’t decrypt a hash output. Its more to create a fingerprint of the input data like passwords and blocks

[Featherstone]

1. What is the hashing algorithm called used in Bitcoin?
2. Why is this hashing algorithm really hard (almost impossible) to brute-force?

1. SHA-256
2. It is infeasible because there are far too many possible options that would need to be tried in order to correctly guess the right one.

[hlo]

1. What is the hashing algorithm called used in Bitcoin?
   sha256
2. Why is this hashing algorithm really hard (almost impossible) to brute-force?
   whatever the input is the output (hash) will always have a 256 bits lenght. its very hard to track the computation

[Reid]

Sorry for the late response. Yes, I wrote a little C++ program but I was not totally sure I got the right answer so I googled it as well and it happened to match. With the program there are register limitations that I had to work around so I coded this and it seemed to work.
Ive been out of coding for many years, so I’m sure there was a better way to do this but here is what I did:

#include
#include <math.h>
#include
using namespace std;
int main()
{
int baseNumber = 2;
for (int i = 1; i <= 256; i++) {

    cout <<fixed << setprecision(0) << i << "  " <<  pow(baseNumber, i) << endl;
}
return 0;

}

---

Seem to work fine.

[waka]

1. SHA-256
2. The task is to find the input X, given a certain output Y of hashing function. However, since k has a high min-entropy, ie drawn from a huge distribution, finding k|x such that H(k|X)=Y, becomes computationally very, very expensive.

[Anoushka]

1.SHA256
2.it would take too long because there are too many possibilities

[pawel]

1. SHA-256 (Secure Hashing Algorithm 256)
2. It takes so looooooong that it doesn’t matter.

[kengin2013]

1. Secure Hashing Algorithm (SHA) 256
2. Because it takes so long to get the input that it doesn’t matter

[ElyRamos]

1. What is the hashing algorithm called used in Bitcoin?
   SHA256
2. Why is this hashing algorithm really hard (almost impossible) to brute-force?

Well its almost impossible , huge large data generating by computers involved minning base on the random

[Kristen_Crandall]

1. SHA-256
2. Because the pre-image resistance takes so long to brute force that it is infeasible.