Reading assignment: Hashing

Blockchain and Bitcoin 101
#1770

  1. What is the hashing algorithm called used in Bitcoin?
    Sha 256.

  2. Why is this hashing algorithm really hard (almost impossible) to brute-force?
    is almost impossible to brute force because it is very difficult to find 2 inputs to produce the same output in a hash function.

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#1771

1- SHA-256
2- because it is very difficult and take a very long time to break

1 Like
#1772

  1. SHA-256

  2. Because of pre image resistance there are so many different variations of addresses that are created from a simple change of the inputs that simply inputing random addresses or guessing an address that had some value to it, it would be so improbable it would take lifetimes.

1 Like
#1773
  1. SHA-256
  2. Due tot the amount of (possible) input data that is hashed, the amount of time required to brute force/‘guess’ the input is nearly impossible.
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#1774
  1. What is the hashing algorithm called used in Bitcoin?

The hashing algorithm used in Bitcoin is called SHA-256

  1. Why is this hashing algorithm really hard (almost impossible) to brute-force?
    The total number of possibilities is too large, and you would have to change every single block since bitcoins creation to be successful, and this would require at least 51% of the network as well
1 Like
#1775
  1. SHA-256
  2. There are too many variables making brute force infeasible within our lifetimes.
1 Like
#1776

  1. SHA - 256

  2. Because even very minor changes in input create massive changes in the outputted hash.

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#1777

What you are explaining is a 51% attack, not brute forcing which is when you want to generate the same hash for an unknown input either by collision of trying to find the exact same input. :slight_smile:
In 51% attack you want to find a new hash below the threshold.

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#1778

This is indeed the property of hash functions and makes brute forcing even more difficult. But the reason its hard to brute force is because of the sheer number of possible outputs :slight_smile:

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#1779

Got you, thank you for your input.

#1780

I appreciate you clarifying that for me too. Makes more sense now.

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#1781 
1. The hashing algorithm in Bitcoin is called sha 256.

2. The hashing algorithm is almost impossible to force due to the sheer number of data. The chance of a random match of both the input and output is infeasible and would take so long to compute it wouldn't matter.
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#1782

1- Sha-256
2 - It is hard to brute force because of pre-image resistance, meaning the likelihood of randomly choosing a has and calculating it’s input is infeasible and would require way too much work

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#1783

  1. What is the hashing algorithm called used in Bitcoin?
    Answer: SHA-256

  2. Why is this hashing algorithm really hard (almost impossible) to brute-force?
    Answer: The hashing algorithm is really hard to brute-force due to pre-image resistance. In pre-image resistance, it is infeasible to determine the input when given the output hash.

2 Likes
#1784
  1. SHA256
  2. It’s hard to brute force because a small change in the input changes the output drastically to another 256bit hash.
1 Like
#1785
  1. SHA-256
    2.The algorithm produces 256-bit output it has a total of 2 to the power of 256 numbers of possible combination even half the amount is still huge. so it would be infeasible to use brute force method to determine the original input or to find collision where 2 different input shares the same hash.
1 Like
#1786
  1. SHA256
  2. to use brute force method, for SHA256, there are a total possible combinations of 2^256. Therefore it is almost impractical/improbable to find the right input to give you the same hash value.
1 Like
#1787
  1. What is the hashing algorithm called used in Bitcoin?

SHA-256

  1. Why is this hashing algorithm really hard (almost impossible) to brute-force?

It still take to long

1 Like
#1788
  1. What is the hashing algorithm called used in Bitcoin?

Sha256

  1. Why is this hashing algorithm really hard (almost impossible) to brute-force?

the sheer number of possibilities resulting from hashing (2^256 possibilities)

1 Like
#1789
  1. SHA-256
  2. The probability is extremely low due to the 128-bit hash, preimaging resistance, etc
1 Like