Reading assignment: Hashing

Blockchain and Bitcoin 101
#704

  • What is the hashing algorithm called used in Bitcoin? SHA256

  • Why is this hashing algorithm really hard (almost impossible) to brute-force? Because it would take so much time to find the correct input that it is unfeasible

#705

Sha 256
The number of computational possibilities is astronomical

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#706

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

[2] This hashing algorithm is almost impossible to break by brute force because of the number of possibilities that one would would have to go through before finding the correct value is very large. For bitcoin (SHA-256), it would be 2^256/2 = 2^255 times = 5.79x10^76 tries on average before breaking the code.

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#707
  1. SHA256
  2. Because small variation in inputs changes output at large. And randomly trying inputs and then hashing and comparing with output result is nearly impossible.
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#708
  1. SHA256
  2. It depends on hash length. if the length is longer than 256-bit, to brute-force is almost impossible because cost (time, resource of computation, etc) is huge.
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#709

‘#’ The hashing algorithm is used to create a fixed-length unique identifier of the block. :id:

The blockchain is a linked list that contains data and a hash pointer that points to its previous block, hence creating the chain. :chains: :loop: It not only contains the address of the previous block but also the hash of the data inside the previous block.

Bitcoin is using SHA-256 hashing, which has 2^128 (in other words 3.4028237e+38) different possibilities, hen It is hard to brute-force.

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#710

  1. SHA256

  2. The algorithm is almost impossible to brute force because it is difficult to find 2 inputs to produce the same output in the hash function

#711
  1. SHA-256
  2. The number of possible inputs to the hashing are is so large it is infeasible to find the correct result in less than 50 to 100 years.
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#712

  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? If you make a small change in your input everything changes with it which means that it doesn’t matter as it takes way too long too brute force.

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#713

  • What is the hashing algorithm called used in Bitcoin? SHA-256

  • Why is this hashing algorithm really hard (almost impossible) to brute-force? Because to figure out the input data on the output data it would take couple of lifetimes, and it is very infeasible to try that :stuck_out_tongue:

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#714

  1. It’s called SHA256.

  2. Because algorithm is made in such way, that is not possible to deconstruct x (input) from the f(x) (output), so the only way to brake it, is just randomly guess the number. And the most beautiful thing is that 2ˆ265 is such a large number, that if you make a 1 guess per 1 second the planet Earth would be long gone, when you get the right answer.

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#715
  1. SHA-256
  2. It would take a looong time to get correc hash - there is too many possibilities.
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#716
  1. SHA-256
  2. It “may” be possible to brute force a hashing algorithm, but in the best case scenario it will take so long that it doesn’t even matter.
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#717
  • What is the hashing algorithm called used in Bitcoin?
    The Hashing algorithm is called SHA- 256.
  • Why is this hashing algorithm really hard (almost impossible) to brute-force?
    Because its preimage resistant, meaning it could take a lifetime to match (by guessing) the hash bits to the data input.
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#718
  • What is the hashing algorithm called used in Bitcoin?

Sha256

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

You would have to spend many lifetimes guessing the hash that corresponds with the inputs

#719

What is the hashing algorithm called used in Bitcoin?
SHA-256

Why is this hashing algorithm really hard (almost impossible) to brute-force?
There are so many possibilities that it would take forever try them all (on average 1,7 X 10^38 tries)

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#720
  1. SHA-256
  2. It would take so long to brute force that it would not matter the end result
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#721

  1. SHA-256

  2. This hashing algorithm is almost impossible to brute force because of five properties that make it secure.

*it is deterministic. The same input will always produce the same hash making it easy to trace.
*quick computation,
*pre image resistant. This means that it is not feasible to obtain input data using hash output. 256 bits of data mean that it is theoretically possible to use the hash sequence to get the input data but it might take you until the end of time to do it.
*small changes in the input changes the hash significantly

  • collision resistant. Highly infeasible that different inputs will produce same hash, if it does happen you have to assume that the same input has been used.
    *puzzle friendly. Hashing uses concatenation to join input with another variable to produce output. I’m a little confused on this final property!
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#722

  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?
    To increase security and make the blockchain immutabile

#723
  1. SHA 256
  2. It’s like trying to please my ex-wife. If I could do it, it wouldn’t be worth it.
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