Reading assignment: Hashing

Blockchain and Bitcoin 101
#986
  1. Sha-256 (secure hashing algorithm 256)
  2. Because the number of possibilities it would take to guess and time consuming
1 Like
#987
  1. SHA-256.
  2. Because it has pre-image resistance.
1 Like
#988

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

  2. Why is this hashing algorithm really hard (almost impossible) to brute-force? Pure random guessing that would never end for humans.

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#989

SHA256
The time it would take to used the 2 imputs to find the same output is unfeasible

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#990

  • What is the hashing algorithm called used in Bitcoin?
    SHA256 (Secure Hashing Algorithm 256)

  • Why is this hashing algorithm really hard (almost impossible) to brute-force?
    It would take take such a long time to try and brute-force (select a random input, compute hash, is it the same as the required hash? NO-Repeat, YES-WINNER!!) one single hash that it doesn’t really matter. The hash would probably be irrelevant by the time it is cracked anyway.

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#991
  1. Sha 256
  2. It would take many life times for 2 inputs to produce the same output.
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#992

1.) Bitcoin uses SHA-256

2.) The amount of possibilities that can be generated is so massive that two people getting the same results is virtually impossible so brute force isn’t a worry.

1 Like
#993

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?

Would take so long to do that in effect it doesn’t matter thus it is infeasible

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#994

That is a collision. To brute force SHA-256, we are talking about finding an input based on a given output. Which is not possible due to so many combinations and since hashing is a one way function.

#995

What is the hashing algorithm called used in Bitcoin?
-SHA-256 (Secure Hashing Algorithm 256)

Why is this hashing algorithm really hard (almost impossible) to brute-force?
-Brute-force is actually guessing,and it would takes so long too find the answer that it doesnt matter.

1 Like
#996
  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?
  • In average occasion, it would take 2^255 = 5.79*10^76 attempts to guess the input.

However, one thing confuses me in the article:

image
image837×397 50.2 KB

Block 3 contains hash of block 2, not vice versa. Why would block 2 change? I think it should say block 4, which in turn would change block 5, and so on, in the other direction.

2 Likes
#997
  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?
    The number of guesses for an individual to try and guess the SHA-256 code that it is nearly impossible.
1 Like
#998
  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?
    It’s pre-image resistance – on average, you need to try 2^127 times to resolve it; also a small change in the input will change the hash in huge.
2 Likes
#999

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

  2. This hashing algorithm is very hard to brute force because the permutations of data points you would have to guess through are extremely numerous. Something like 2^127 different data points would have to be guessed and tested, on average. This feature is referred to as pre-image resistance. (Thank you to the poster above me for reminding me of that term).

3 Likes
#1000

  1. Sha 256

  2. Because the nounce must be changed many times until the requirements are met.

2 Likes
#1001

SHA-256 hash algorithm

The total number of possibilities is so large it makes it almost impossible to guess right

1 Like
#1002
  1. SHA-256
  2. The fixed length output essentially cannot be undone to determine the input. not impossible, but would take longer than its worth. potentially a lifetime, or more.
1 Like
#1003
  1. SHA 256
  2. Because the smallest change to input data will drasctically change the output hash. Random Brute force will take way too long & is therefore unfeasable.
1 Like
#1004
  1. SHA 256
  2. Impossible to bruteforce the possibilities of 2^256. One input only one output.
1 Like
#1005
  1. SHA-256 (Secure Hashing Algorithm 256)
  2. The number of possibilities to determine the input based on the hashed output is so high that it does not pose an issue during one’s lifetime.
1 Like