Reading assignment: Hashing

Blockchain and Bitcoin 101
#2211

SHA256 solutions are finite, around 2^256. It is a bit less due to the way the function works. :slight_smile:

#2212

Mining has nothing to do with SHA256 on itself. Mining uses hashing in the mining process.

#2213
  1. sha256
  2. In order to brute force, ei, selecting a random number and run through the cryptographic hash string you will need “colossal” computing power. Eveb if the entropy in sha256 theoretically could be brute forced it is so high-min that the risk is negligibly small.
2 Likes
#2214

1: SHA-256
2: if the inputs are slightly changed you already get a completely different hash output, this property makes it extremely difficult to get certain inputs matching a output.

1 Like
#2215
  1. The SHA-256 or Secure Hashing Algorithm
  2. Because there are to many possible solutions so to try them 1 by 1 will take a loooooong time
1 Like
#2216

  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 there are 2256 possible answers. Going through them one by one would take years with even the fastest computer, in other words, it would cost more in time and energy than it is worth.

1 Like
#2217
  1. What is the hashing algorithm called used in Bitcoin?
  • It is SHA - 256 - it means that it takes input as transaction and for output you will get a 256 bit code as a fixed length.
  1. Why is this hashing algorithm really hard (almost impossible) to brute-force?

  • Every input has it specific output and to know which hash is it you have to guess by trying and for a large amout of data you will spend ages to get the result.

  • If you want to make a change in the hashing algo. and no matter how small the change is the output of the hash is significant.

1 Like
#2218

1- Bitcoin hashing algorithm is called SHA-256 (Secure Hashing Algorithm 256)
2- The hashing algorithm is really hard to brute-force because it is almost impossible to randomly determine the value of an encrypted input from the output due to the size of data at play

1 Like
#2219

  1. SHA-256

  2. It is almost impossible to brute-force the algorithm due to the computational power necessary.

1 Like
#2220

SHA 256. There are so many computations it would take too long.

1 Like
#2221

  1. SHA 256

  2. Hashing algorithm is very hard to be brute-forced because it would take a huge amount of time and resources.

1 Like
#2222

  1. Bitcoin uses the SHA-256 hashing algorithm.

  2. It’s hard to brute-force because, every with a small data set, it is nearly impossible to guess the sequence of a SHA-256 hashing algorithm. It’s not worth the effort.

2 Likes
#2223

  1. SHA 256

  2. This hashing algorithm is hard to crack with brute force for one because each hash contains the hash of the parent block so to alter one data set would require alteration of all previous data sets which would be infeasible because altering even a small set of data alters the hash nearly completely. And then hackers would still have to concatenate it with a randomly chosen nonce and then compare the hash to the difficulty level and repeat… Meanwhile the rest of the blockchain would be creating more valid hashes and solidifying the correct data. There are so many possibilities of hash outputs in this type of encryption that we would need to live longer to have a collision of hashes.

2 Likes
#2224
  1. What is the hashing algorithm called used in Bitcoin?

SHA(Secure Hashing Algorithm)-256

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

Its immutability.

"The blockchain is a linked list that contains data and a hash pointer that points to its previous block, hence creating the chain. What is a hash pointer? A hash pointer is similar to a pointer, but instead of just containing the address of the previous block it also contains the hash of the data inside the previous block . This one small tweak is what makes blockchains so amazingly reliable and trailblazing.

Imagine this for a second, a hacker attacks block 3 and tries to change the data. Because of the properties of hash functions, a slight change in data will change the hash drastically. This means that any slight changes made in block 3, will change the hash which is stored in block 2, now that in turn will change the data and the hash of block 2 which will result in changes in block 1 and so on and so forth. This will completely change the chain, which is impossible.

This is exactly how blockchains attain immutability."

2 Likes
#2225
  1. Sha-256
  2. To be able to find the data pre hashing, you would have to take a random guess at what that data is. The amount of options to randomly guess is so small that it is virtually impossible to guess on 1 try. The system is also designed to include the amount of options needed, to be so high, that someone couldn’t run a software program that could do this fast enough and often enough to become a statistical liability.
2 Likes
#2226

1 = SHA 256

2 = without knowing what output corresponds to which input it would take a person centuries to guess or stumble upon the right output that corresponds to the correct input

2 Likes
#2227
  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?

Because the number of computational possibilities with this hashing algorithm is so high that it would take many lifetimes to solve, making it actually infeasible.

2 Likes
#2228

Hashing has nothing to do with mining. Mining is utilizes hash functions to ensure the immutability of the block.
The reason hash functions in itself are hard to brute force is by the sheer number of possible output. :slight_smile:

4 Likes
#2229
  1. SHA-256
  2. The number of possibilities is so huge that it is not feasible that two people will get the same result in their lifes.
2 Likes
#2230
  1. Sha-256
    1. The number of computational possibilities is so high with a 256 hash that it would make brute forcing impossible.
2 Likes