Reading assignment: Hashing

Blockchain and Bitcoin 101
#3675

  1. Bitcoin use the Secure Hash Algorithm (SHA) named SHA-256 , invented by the National Security Agency (NSA) within the USA.

  2. A Bitcoin hash is only solved in a linear, unidirectional manner, It is impossibile to reverse and obtain the original input from the outcoming hash. This one-way mechanism is guaranteed through intricate mathematical equations which do not allow the reversal of a new hash.

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#3676
  1. Secure Hash Algorithm (SHA) named SHA-256
  2. It is difficult because the function is one-directonal and the input cannot be dehashed back from the output. Also the theoretical attempts to recreate the input from the hashed output would be a very large number, therefore not feasible for many individuals or organizations.
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#3677
  1. What is the hashing algorithm called used in Bitcoin?
    SHA-256 (Secure Hash Algorithm)
  2. Why is this hashing algorithm really hard (almost impossible) to brute-force? Uni-directional, not feasible to solve backwards.
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#3678
  1. The algorithm is SHA-256
  2. The hash function is unidirectional, hashes cannot be reversed
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#3679

  1. Secure Hash Algorithm (SHA-256)

  2. This one-way mechanism is guaranteed through intricate mathematical equations which do not allow the reversal of a new hash. Therefore, a Bitcoin hash is only solved in a linear, unidirectional manner.

1 Like
#3680
  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? SHA-256 is designed to be a linear algorithm that makes it impossible to figure out the original input by “reverse engineering” the problem.
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#3681
  1. What is the hashing algorithm called used in Bitcoin?
    -SHA256
  2. Why is this hashing algorithm really hard (almost impossible) to brute-force?
    -due to large computation require
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#3682

  • Bitcoin uses a Secure Hashing Algorithm (SHA-256), created by the NSA. SHA-256 is commonly used as the gold standard for HTTPS website encryption amongst other things. SHA-256 is extremely hard to break which makes brute force attacks ineffective.

  • The Bitcoin Blockchain runs off Proof of Work (PoW) which uses computational power to process and solve the SHA-256 hash that is produced when a transaction is made. Transactions are created and stored in a block that is mined by computers (miners) on the network offering processing power. Miners are rewarded by earning rewards from solving blocks. The Blockchain has the ability to balance processing power. It can introduce mining difficulty when too many miners are online and reduce the difficulty when there are too few, rewarding miners more when there are fewer online or demand increases.

Bitcoin’s Blockchain can be considered as a giant interconnected cloud computer with more processing power than every supercomputer in the world combined. There is not a DDoS solution in the world that has enough power to overwhelm the Bitcoin Blockchain. This makes it extremely reliable and safe. Additionally, blockchains decentralized nature prevents a Single Point of Failure (SPoF) as all computers on the network have a valid copy of the chain.

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#3683

  1. SHA-256

  2. Hashing algorithms are extremely difficult to solve and only work in a unidirectional fashion. It is impossible to reverse engineer a SHA-256 hash. Also they are very large, basically making it impossible for a computer to guess or at least it would take a VERY long time.

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#3684

Q: What is the hashing algorithm called used in Bitcoin?
A: SHA256, and is one of the six families of functions of the SHA-2 family, which is a set of cryptographic hash functions create by the National Security Agency

Q: Why is this hashing algorithm really hard (almost impossible) to brute-force?
A: The stunning number of computational possibilities of using SHA256 would require a time that is not nearly within the 10 minutes time frame before the next block is produced (2^256 is actually larger than the number of atoms within the known universe) :slight_smile:

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#3685

What is the hashing algorithm called used in Bitcoin?
It’s SHA-256.

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

Because it is almost impossible to reconstruct the initial data from the hash value. A brute-force attack would need to make 2^256 attempts to generate the initial data. It’s really unlikely to find what input would generate a specific output in this function. And also a minor change to the original data alters the hash value so much that it’s not apparent the new hash value is derived from similar data.

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#3686
  1. SHA-256
  2. because the output cannot be reversed to the data input.
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#3687
  1. Secure Hash Algorithm 256 Bit - SHA-256
  2. The hashing algorithm is extremely difficult to reverse as the output is unidirectional. Its also a enormous amount of computational possibilities that would not be possible within the timeframe before the new block.
1 Like
#3688
  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 this hashing algorithm cannot be reversed to calculate initial raw data. It is a one-way mechanism and does not allow reversal of new hash. It can only be solved in a linear, uni-directional manner.
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#3689
  1. The hashing algorithm used in Bitcoin is SHA-256
  2. The hashing algorithm is almost impossible to brute-force because it can take any input of any length or size, and translates it to a fixed length. It is one way so the output cannot be used to calculate the input. The amount of guesses the brute force method would have to take is so high that it isn’t even worth it to try.
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#3690
  1. SHA-256
  2. The hashing algorithm is a one-way mechanism, meaning that it cannot be reverse-engineered and the solution cannot be found iteratively. There are up to 256 bits of code involved, creating a huge number of possible answers and intense computation to create a new block by finding the solution i.e. proof of work.
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#3691

1 - SHA-256
2 - Competition limits the time one would have to brute force and there are 2^256 possible combinations

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#3692
  1. SHA 256
  2. It would take so long that it is not feasible.
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#3693
  1. SHA-256 (secure hash algorithm - 256bit)
  2. It is hard because the possibility of guessing the next Hashtag is very slim, and it requires special software and hardware with great computational power. The hardware should be at atleast capable of guessing TH/s.
1 Like
#3694

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

  2. Why is this hashing algorithm really hard (almost impossible) to brute-force?
    I have a question to this question, please do let me know.
    If that one time of brute force incident really does occur somehow through random chance , how will it affect bitcoin ? And will it take a longer time for a second occurrence to happen again ?

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