Reading assignment: Hashing

Blockchain and Bitcoin 101
#483
  1. The hash algorithm in bitcoin is called SHA-256 (Secure Hashing Algorithm 256)
  2. You have to bruteforce the input (those a random input and try it out), this is close to possible.
#484
  1. SHA-256
  2. You pick a random input, hash it and compare it with the output hash. Does it not match, try again with another random input hah it etc.
#485
  1. What is the hashing algorithm called used in Bitcoin?
    Bitcoin uses SHA 256 which produces a fixed length output of 256 no matter how long the input was.
  2. Why is this hashing algorithm really hard (almost impossible) to brute-force?
    Brute-force is based on guessing, it is very difficult to guess rightly from hashing. It will take anyone very long time to guess correctly which will cause the guesser to give up.
#486

1/ What is the hashing algorithm called used in Bitcoin.

Bitcoin produces SHA 256 -bithash.

2/ Why is the hashing algorithm really hard ( almost impossible ) to brute force.

The hashing Algorithm is too big to brute force, it would take that long, that in the end its not viable.
To pick up a random input, hash it, & repeat it until you find a match…you would have to be the luckiest person in the world…its not about luck its about protocol.

#487

1/ What is the hashing algorithm called used in Bitcoin?
SHA-256
(*SHA stands for SECURE HASHING ALGORITHM and 256 for BITS)

2/ Why is this hashing algorithm really hard (almost impossible) to brute-force?
It would require too much computations / time / energy to brute-force … in fact 2^256 meaning an infinite amount of possible inputs where the length of the “input” can be whatever size

#488
  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 process would take so long to to figure out that it’s inefficient & infeasible.
#489
  1. SHA-256
  2. Because it uses the hash of the combined high min-entropy value (nonce) concatonated with the hash of the block. The likelihood of guessing the correct output value is infinitesimally small (infeasible)…
#490

  1. The hashing algorithm used in Bitcoin is called sha 256

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

#491

A:

  1. SHA-256

  2. Sha-256 outputs a 78 digit number. A number so large that it is extremely unlikely so as to be able to go through all possible solutions within the 10 minute block time.

#492

Hi,
1, SHA-256
2, Try randomly guess a number in pool 2^128… its 340,282,366,920,938,463,463,374,607,431,768,211,456
7,777,718,871 - how many people is on earth + -
1,000,000,000,000,000,000,000,000 - “expected” number of stars in space
There is probably higher chance that i will meet alliens today then chance ill gues number above.
So whole system is very resilient to brute-force currently.

#493

  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 it would take a lot of time to do that and thats not worth it

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#494
  1. What is the hashing algorithm called used in Bitcoin?
  • SHA-256 (Secure Hashing Algorithm 256).
  1. Why is this hashing algorithm really hard (almost impossible) to brute-force?
  • There are such an astronomical amount of possibilities that it is infeasible to be brute forced. Pre-image resistance and that fact that small changes in the input changes the hash.
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#495

The input will not appear, but you need to guess it, hash it and check if the hash is the same or not. (and repeat until you find the correct input producing that hash)
It’s like brute forcing a pincode by trying all possible combinations

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#496

You are describing a hash collision. Brute forcing a hash means guessing the input, hash it and check if the hash is the same or not (and repeat)

#497

But it’s not all about numbers, you can hash whatever string of text as well to guess the input of a hash that matches the one you want to brute force

#498

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 those 6 properties.
1-Deterministic
2-Quick Computation
3-Pre-Image Resistance
4-Small changes in Input change the whole Output
5-Collision Resistant
6-Puzzle Friendly

1 Like
#499

Answer 1: SHA256 algorithm
Answer 2: It is nearly impossible to find the input based on the output from the hashing algorithm. The output is totally unrelated to the input.

1 Like
#500

it takes to much power to try

#501

sha252 is the code for bitcoin

#502

sha252 is the code for bitcoin sorry sha 256