Reading assignment: Hashing

Blockchain and Bitcoin 101
#2632

1 SHA-256 invented by US NSA

2 To brute-force something means to try all the possible combinations until you find the solution.

IE 3 digits briefcase lock, has a total of 1000 possible combination, 4 digits lock, would already have 10.000 possible combinations.
(under the assumption that we have a lock with separate dials for each number, and that it uses only the numerical digits 0–9)

So how about Bitcoin? How many combinations we have there? The number is so high that we cant really imagine. To brute-force 256 Alphanumeric hash algorithm would take almost infinite time.

To make it more easy to understand what it takes Andreas Antonopoulos gave a good answer to this: "Every atom of the matter in the entire observable universe, of hundred billion galaxies and more, everything that is making up everything that we can observe in our space/time, everything could have its own private key." So good luck guessing that private key.

https://www.youtube.com/watch?v=2eZ5DP2P5As

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#2633

  1. The hashing Algorithm is called SHA-256

  2. The hash output is so different to the input that it’s statistically improbably that the exact input could every be found.

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#2634
  1. SHA-256
  2. Varying the block’s header is a trial and error process and the chances of success are statistically very low. With so many possibilities, mining [requires high amounts of computational capacity.Length has to be the same, input length as the output
2 Likes
#2635
  1. A Secure Hash Algorithm called SHA-256
  2. Because the hash algorithms are unidirectional - the output cannot be reversed to reveal the initial input
1 Like
#2636
  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 of the many computation options it would be nearly impossible
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#2637

  1. SHA-256

  2. SHA-256 has 256 digits in its hash, with current computing power, the chances of brute-forcing a result is negligible.

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#2638

Hash functions on itself have nothing to do with mining. Hash functions are merely used in the mining process to assure integrity of the blocks. The reason why its hard to brute force is because of the sheer number of possible outputs of a hash function.
Also the input to a hash function can be any length. The output has a fixed length :slight_smile:

#2639
  1. 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.”(https://www.cryptimi.com/guides/what-is-bitcoin-hash)
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#2640
  1. SHA-256
  2. Because it is unidirectional, and would take a very very long time to computationally guess the input.
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#2641

Thank you, still this operations are quite confusion to me…thank you for correcting me :heart_eyes:

#2642
  • What is the hashing algorithm called used in Bitcoin?
    SHA-256
  • Why is this hashing algorithm really hard (almost impossible) to brute-force?
    Hashing is a one way process with the original contents being reduced into a number of characters - the example given being a good one equating this to blending food ingredients - the nutrients remain but the ingredients cannot be reconstructed.
1 Like
#2643
  • What is the hashing algorithm called used in Bitcoin?

SHA-256

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

Secure Hash Algorithm - 256 created by the NSA in the USA, is almost impossible to brute-force b/c it’s a one-way hash algorithm able to receive any form or size of data and translate the data into an alpha-numeric 256-bit string output.

I wonder if the new quantum-based computers will be able to “brute-force” this algorithm!?

Thoughts?

1 Like
#2644

  1. A Secure Hash Algorithm called SHA-256

  2. This is because the input of a hash function can have any length but will have an output at a length that is fixed. The number of possible hashes are also so high that the it would be nearly impossible solve.

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#2645

SHA 256 hashing algorithm

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#2646
  1. SHA-256
  2. The hashing algorithm in my opinion is really hard due to the incredible combination of the 256 numbers letters or characters combinations. The odds of 2 miners hitting the same sequence is almost impossible. But, my research shows the wall street fintech Treadwell Stanton DuPont research and development and sciences team successfully broke the SHA-256 hashing algorithm silently in controlled laboratory conditions on Sept 11, 2019.
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#2647

interesting… any links to that info? Quantum-based computing??

#2648
  1. Secure Hash Algorithm (SHA) SHA-256
  2. It takes great computational power to hash and is becoming increasingly more difficult. Miners are essentially part of a lottery and this makes is a game of chance to be awarded the block, let alone doing it by brute force. Also the other nodes must confirm the hash.
1 Like
#2649
  1. SHA-256
  2. It would take lot of time, patience and resources to mine a hash due to the complex system that is integrated to it and the amount of combinations to access the hash are many but only one works.
1 Like
#2650
  1. What is the hashing algorithm called used in Bitcoin?
    a. Secure Hash Algorithm (SHA) named SHA-256
  2. Why is this hashing algorithm really hard (almost impossible) to brute-force?
    a. Complexity of the algorithm, the modified/specialized hardware, software required and the power.
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#2651

Quantum computers as of today are only capable of performing specific tasks and there is no way of knowing what the future might bring. Even if one day a computer will be able to break SHA256 the network could hard fork to a new algo that is resistant to the machines of the future. :slight_smile:

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