SHA-256 Secure Hashing Algorithm
Because it would require randomly guessing a value out of a gigantic number of possibilities. Thus statistically is should take such a long time that there is not need to worry about it happening.
Awesome, you really got it! Good job 
2.No matter the input size the output will be 2^256.The large number of input make guessing the hash difficult and resist against brute-force.
The hashing algorithm used in Bitcoin is called: Secure Hashing Algorithm 256 ( SHA-256).
This hashing algorithm is very difficult to brute force due to pre-image resistance feature, meaning the chances of finding the actual input by reverse computation is 2^256 which makes the task not worth while.
What is the hashing algorithm called used in Bitcoin?
SHA-256 (Secure Hashing Algorithm 256)
Why is this hashing algorithm really hard (almost impossible) to brute-force?
Because th enumber of possibilties to have the same result is so large,it will takes life time to get the same result.
What is the hashing algorithm called used in Bitcoin?
SHA256
Why is this hashing algorithm really hard (almost impossible) to brute-force?
Because you have to have the same length of input data and the same length of output data.
This means that it take life time to guess the input
1.- SHA256
2.- It is ridiculously unlikely for you to guess the input based in the output
1) What is the hashing algorithm called used in Bitcoin?
The hashing algorithm for Bitcoin is called SHA-256, Secure Hashing Algorithm 256. SHA-256 takes in an input string of any length and produces an output of a fixed length. No matter how small or big the original input, the output will always have a fixed length of 256 bits length.
2) Why is this hashing algorithm really hard (almost impossible) to brute-force?
If you attempted to use the brute-force method by randomly selecting an input, hash it and then compare the output with the target hash and find an exact match, on average it would take you 2^127 times to get a match. That is a huge number which means that it would take you an extraordinary amount of time to find a match. Moreover, if there is even a small change in the input at any given time, the hash output would change dramatically to make it almost impossible to find the match.
Now, with the development of Quantum Computer where not only the computing power is quite high but it also solves problems using probabilistic operations, these times would not be radically shortened?
Not sure, but quantum computers today are only good at a specific task and quantum resistant algorithms are already being developed.
In case SHA256 does eventually get broken in the future, a network will have to hard fork to replace it with a more robust algo. At the current pace of processor speeds progressing according to Moores law, it will take a few more generations for SHA256 to be broken. 
The hashing algorithm used in bitcoin is called SHA-256.
Sha-256 is really hard to brute force because of the time and random guesses that are required to decrypt a hash. Given the nature of SHA-256, it is very difficult to determine the content of a hash. Since a hash is constant in its output, the input information could be simple or complicated. You either have to be really lucky, or have a lot of time.
This is good to know. Would the value of bitcoin 1.0 decrease as a result of super-computers being able to break the encryptions of hashes?
This is all part of speculation. But I’m guessing there would be a certain drop in value at the time when and if this occurs because of people panic selling.