Reading assignment: Hashing

Blockchain and Bitcoin 101
#4339

  1. What is the hashing algorithm called used in Bitcoin?
    Bitcoin uses SHA 256 as the hashing algorithm

  2. Why is this hashing algorithm really hard (almost impossible) to brute-force?
    it is impossible to find the input based on the output, each input has its own hash

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#4340
  1. SHA 256 is the hashing algorithm used in Bitcoin
  2. It is hard to brute-force because what length of input data, you have same length of output data.
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#4341

1.Bitcoin Hash Algorithm which is SHA-256
2. Because the hash changes with every slight variation of input, thus is virtually impossible to brute-force.

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#4342
  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’s a one way function that takes in the data and outputs a cryptographic hash of a defined range which depends on the hashing algorithm. To further secure this a nonce is added of a random value in connection with a particular size to add variability to the hash output since the hash function is deterministic, that the same input should get the same result, the nonce and potentially other areas of implementation can add to the variability to get that unique hash. The miners job is to determine this based on the current difficulty. Once the correct nonce is found, the consensus process starts where the other nodes (minors) can verify this and agree as a group, hence the concept of POW, proof of work.

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#4343
  1. SHA - 256
  2. don’t really know…
#4344

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?
Because rewards are not issued simply because the computation was completed. The submitted hash’s random number value still has to land below the target. So a brute force attack would at best only solve the first half of the puzzle.

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#4345

What is the hashing algorithm called used in Bitcoin?
The hash algorithm is a universal translator that takes any size of data (digits, letters and media files) and translate them into a aplhanumeric string. The especific version of the hash algorithmic used by the bitcoin network is SHA - 256.

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

Because the data is wrapped inside a linear strutcture that produces a string with 256bits of alphanumeric information, and to acess the original hash (with all information) you have to feed the network with the exactly the same data in the same order. By setting computers to process the data (valideting the transactions inside the network) and produces de hash, the miners gain the chance to produce the right string. Thus, to brute-force the network, you have to set a computing power high enogh, not just to produce de same hash, but surpass all the others computers that are producing new hashs.

In simple words: the computing power demanded to brute force the network cant be found withim the nowadays. The existing computing power today avaliable will take several hundreds of years.

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#4346

brute-force method means that you have to pick up a random input, hash it and then compare the output with the target hash and repeat until you find a match, suppose you are dealing with 128-bits hash, in the worst scenario you will get it after 2^128 times which is a very huge number and impractical. Let take the average scenario which you can get in the middle which is after (2^128)/2 = 1.7e38 still a big number. To recap my point it is infeasible to find the input using brute force.

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#4347
  1. SHA-256
  2. The slightest change to input data results in a completely different hash. So attempting brute-force could involve so many input guesses that it would be virtually impossible to arrive at a correct solution within the lifetime of the entity attempting brute-force.
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#4348

Oh i see thank you, it makes it a lot more clear!

#4349

  1. What is the hashing algorithm called used in Bitcoin?
    SHA256

  2. Why is this hashing algorithm really hard (almost impossible) to brute-force?
    Because the total number of possibilities is big that it need impossible numbers of trials to achieve it.

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#4350

  1. SHA-256, which is a “Secure Hash Algorithm” (SHA)

  2. Miners have to solve increasingly difficult mathematical equations

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#4351

  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?
    Because the reward is randomly distributed, so force isn’t the way to be able to guarantee getting the block

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#4352
  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?
    Its hard to brute-force because hash blocks are solved trough really difficult mathematical equations which do not allow the reversal of a new hash.
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#4353

Reading Assignment: Hashing - Answers

  1. Bitcoin uses the SHA-256 hash algorithm

  2. SHA-256 is an SHA-2 family hashing algorithm that is constructed stronger than SHA-1 type hashing such as MD5. Using modern GPUs, it would take trillions of years to brute force by iterating each hash.

“The maximum cycle length is 2ˆ256 ≈ 1.16×1077 iterations. If you can evaluate 1012 hashes per second, then working your way through all possible hashes would take you about 1065 seconds (about one quindecillion times the age of the earth). Even if you’re fortunate enough find a loop in a tiny fraction of that time, you’re still liable to be waiting for trillions of years.”

Also…
“*If every atom in our galaxy was used to store a separate hash value, you would run out of space after storing less than one-billionth of the total number of hashes.
(Source: number of atoms in milky way galaxy ≈ 1068)*”

Source: https://stackoverflow.com/questions/43634996/how-long-would-it-take-for-a-sha256-digest-loop-to-reach-the-original-hash-or-st

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#4354

  1. What is the hashing algorithm called used in Bitcoin?
    a. Secure Hash Algorithm or SHA(256)

  2. Why is this hashing algorithm really hard (almost impossible) to brute-force?
    b. They can only be solved, they cannot be reversed to find the original data.

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#4355

  1. What is the hashing algorithm called used in Bitcoin?
    secure hash algorithm (SHA) - Sha-256

  2. Why is this hashing algorithm really hard (almost impossible) to brute-force?
    Bitcoin hash-rate is only solved in a linear, unidirectional manner, this one-way mechanism is guaranteed through intricate mathematical equations that don’t allow the reversal of a new hash, furthermore the computational requirements increase as the mathematical equations required to be solved by miners become more and more harder to solve.

1 Like
#4356

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

  2. Why is this hashing algorithm really hard (almost impossible) to brute-force?
    By brute-force method we have to pick up a random input, hash it and then compare the output with the target hash and repeat until we can find a match. Basically we have to sort of bee the luckiest people in the world for this to happen. The odds of this happening are astronomical.
    We can get our answer after 2^128 – 1 times. Basically, it means that we will find our answer at the end of all the data.
    Average scenario: We will find it somewhere in the middle so basically after 2^128/2 = 2^127 times. To put that into perspective, 2^127 = 1.7 X 10^38. In other words, it is a huge number, a lot of data involved… via the brute force method, it takes too long, small changes In the Input changes the Hash and even small change in our input, will show the huge changes that will be reflected in the hash. Practically impossible to find the input to produce the same output in a hash function taking into account the numbers above.

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#4357
  1. What is the hashing algorithm called used in Bitcoin?
    SHA-256 (Secured Hashing Algorithm 256 bits)
  2. Why is this hashing algorithm really hard (almost impossible) to brute-force?
    Because the number of different possible answers is very very high (256 digits) making it nearly impossible to guess from a probability standpoint.
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#4358
  1. SHA -256
  2. This would take 51% or more of the network to agree. Most miners would not be ok with this since they are rewarded by following protocol
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