Reading assignment: Hashing

[GoBeeGo]

1. sha 256.

2. because it take a lot of computational effort.

[jjohnson]

1. What is the hashing algorithm called used in Bitcoin? The algorithm Bitcoin uses is SHA-256
2. Why is this hashing algorithm really hard (almost impossible) to brute-force? The many computations possibilities are so high making it impossible for brute force to be achieved.

[moza8]

1. SHA-256
2. Because it has so many different solutions that is very time consuming.

[Margaret]

1. SHA-256 (Secure Hashing Algorithm 256).
2. Brute forcing is hard because there are 128 bits in a hash and even tiny differences in an input generate a vastly different hash output. Because of this, you would need to randomly select inputs and compare outputs which could take as long as the entire data string which would be 2 to the power of 128 possible input selections before you ran across a collision or match. It can be done but by the time it was computed, the query would no longer be of any value

[a.ekasdornkorn]

Bitcoin hashing uses SHA-256

Brute force for exponentially high numbers is not feasible, taking too long and too much energy to make it worthwhile

[Sabine]

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?
   -> it would take an exagerated long time to find out the input that has been hashed. It is not impossible but economically “not feasible” for who wants to brute-force.

[Albert777]

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

It is called SHA 256

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

Because SHA 256 has a number extremely high of different combinations so, even if no hash function is totally collision free, still it is extemely hard to find a collision.

[DeezSats]

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?
   It is nearly impossible to brute force because of the necessary property called pre-image resistance. Because the hash is 256 bits the ability to determine the original input is near impossible. Infeasible is the word they liked to use in our homework reading assignment.

[Delta4s2Cyclone]

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?
   Breaking pre-image resistance using brute-force algorithm can be possible but given the fact that the underlying data is so huge that it would take very long time and thus it’s really hard.

[RobertRedBeard]

1.) The hashing algorithm that Bitcoin uses is called SHA-256.

2.) This is really hard in order to create a certain level of difficulty so that it takes a certain amount of time on average to get the input based on the output.

[Rockydigital]

1. The hashing algorithm used in Bitcoin is called sha-256 (secure hashing algorithm.)

2. The hashing algorithm used in cryptographic hashing is extremely hard to find with brute force (a.k.a pure random guesses) because of sheer amount the possibilities. It would take more than a few lifetimes to go through them all. Thus making the cryptographic hash function secure.

[Les]

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 pre-image resistance; one basically has to guess what the input is, hash it and then compare the output to the desired hash. Being likely
   one can guess results in many iterations,

[Fabrice]

@Margaret

Brute forcing is hard because there are 128 bits in a hash

A Sha256 hash has 256 bits or 64 hexadecimal digits. 1 hexadecimal digit is 4 bits (half a byte = nibble)

[Fabrice]

@Hardeep

The algorithm is SHA-256 (256 bit Secure Hash Algorithm), which always produces a 64-byte hexadecimal character string regardless of the size of the input text.

Sha256 is 256bits or 32 bytes or 64 hexadecimal digits.
1 byte = 8bits
1 hex = 1 nibble (4bits)

[Fabrice]

@travis_bazile

it is very hard to find 2 inputs that produce the same output hash.

You’re describing a collision. Brute forcing a hash means guessing the input over and over again until it matches the hash you want to brute force. It will take you to much time and energy that it isn’t worth it.

[Fabrice]

@jcampos

It’s SHA-254

Bitcoin uses Sha256.
(256bits or 64 hexadecimal digits)

[Fabrice]

@Dom

It would take donkey-monkey years probably a couple of centuries to get the same out put from two different inputs.

Getting the same output of 2 different inputs is called a collision. Brute forcing a Sha256 hash is guessing the input over and over until it matches the hash you want to brute force.

[Fabrice]

@rbrownlow

The possibility of 2 inputs creating the same output are so minuscule, it would take several lifetimes to occur.

You’re describing a collision. Brute forcing a hash means guessing the input over and over again until it matches the hash you want to brute force. It will take you to much time and energy that it isn’t worth it.

[zzzsoren]

@ivan

1. What is the hashing algorithm called used in Bitcoin?
2. Why is this hashing algorithm really hard (almost impossible) to brute-force?

Answer 1:
SHA256

Answer 2:
Because of low probability of guessing the input.

[jcampos]

Thank you,!!! yes, I wrote it wrong.