Reading assignment: Hashing

Blockchain and Bitcoin 101
#1950

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

  2. Why is this hashing algorithm really hard (almost impossible) to brute-force?
    To solve you would need to take a random input and has it and then compare the output to your target hash and repeat until a match is found. The probability to do this is very small.

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#1951
  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 amount of time required to randomly guess the input used to create a certain hashing algorithm output is astronomical. But, with the advent of quantum computers, some have suggested that even more secure and complex hashing algorithms are required to maintain security.
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#1952
  1. SHA-256
  2. Because every input has its own unique hash that is an fixed 256-bits length of data, any small changes in the input will change the rest of the blocks automatically
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#1953
  1. SHA256
  2. It would be very difficult to brute-force the possibilities would take more than a lifetime.
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#1954
  1. SHA-256
  2. Because trying to manually put in every input could take longer than 4 lifetimes to find the correct output.
    ??? I have a question about question 2.??? If they can get a quantum computer to do nothing but put in different inputs wouldn’t it be possible for someone to figure out and output fairly quickly???
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#1955
  1. SHA- 256
  2. There are so many possible combinations that it takes an incredible amount of time to brute-force the correct one.
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#1956

SHA 256

It would take way to long to ever expect to brute force break the algo.

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#1957

SHA-256 (Secure Hashing Algorithm 256)

Picking random inputs to find a matching output hash would take such a long time as to make it nearly impossible.

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#1958
  1. HSA-256.
  2. Because, on average, it would take 1.7 x 10^38 times to try random inputs, hash them and then compare the outputs until you find a match.
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#1959
  1. What is the hashing algorithm called used in Bitcoin?
  • SHA-256, Secure Hashing Algorithm
  1. Why is this hashing algorithm really hard (almost impossible) to brute-force?
  • because of the nonce (a randomly generated string) being added to the hash of the block.
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#1960
  1. Sha256
  2. The combined computer power upholding the hashing power is very high.
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#1961

  1. Secure Hashing Algorithm 256 (SHA-256)

  2. The difficulty is adjusted as mining power grows. The number of “wrong” answers is huge. A computer would need more than billions of years to randomly find the answer. There is no known way to reverse-engineer the answer.

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#1962
  1. SHA-256
    2.the total number of solutions is so large that brute forcing will take a really long time
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#1963

The algorithm is SHA-256 is deterministic

Brute is almost impossible because a small change transforms the whole hash and a 128bits needs 1.7x10^38 so without luck and no permutation in the meanwhile, its too long for the benefit

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#1964

  1. SHA-256

  2. Small changes in the input of data completely changes the hash of the output, therefore trying to brute force the input data from an output has is near impossible as there are so many potential outputs it would take more than a lifetime to solve.

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#1965
  1. SHA 256
  2. The time it would take to compute a brute-force attack
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#1966

We don’t know because quantum computers are still in early stage and can mostly do very specific tasks. However quantum resistant algorithms are already being developed and in case SHA gets hacked by it at some pint in the future, we can do a hardfork to switch to a more resilient algorithm :slight_smile:

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#1967

Nonces don’t have anything to do with hash functions. It is just a part of the input to a function when the block is being mined.
The reason why its hard to brute force is because of the huge amount of possible outputs of the SHA256 hash function. :slight_smile:

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#1968

Mining uses hash functions to mine blocks, but hash functions on their own don’t have anything to do with it. Hash power is the network power of generating these hashes. But even the overall hash power of the network is still not enough to be able to brute force the SHA256 hash function because of all the possible outputs.
Miners are just searching for the output hash that is below a certain target by changing the nonce, not a specific value which is the case in brute forcing :slight_smile:

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#1969
  1. SHA-256
  2. It will take too much time to brute-force.
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