What Is Hashing in Blockchain?

The video explains the concept of hashes and hash functions, emphasizing their importance in cryptography and blockchain technology. It details the characteristics of cryptographic hash functions, such as determinism, speed, one-way operation, sensitivity to input changes, and collision resistance. The video also addresses security concerns and the robustness of SHA-256, concluding with a summary of key points.

What is the primary role of a hash in modern cryptography?

• To store data securely

• To serve as a workhorse in cryptography

• To encrypt data

• To generate random numbers

What is a key feature of a hash function?

• It produces outputs of varying lengths

• It generates a fixed-size output

• It requires a password to function

• It can only process numerical data

Why must a cryptographic hash function be one-way?

• To ensure the output is always the same

• To allow easy reversibility

• To prevent the input from being derived from the output

• To make the function faster

What happens to the hash output when a small change is made to the input?

• The output becomes zero

• The output changes significantly

• The output changes slightly

• The output remains the same

What is a collision in the context of hash functions?

• When a hash function takes too long to compute

• When two different inputs produce the same hash

• When a hash function runs out of memory

• When a hash function fails to produce an output

Why is SHA-256 considered secure despite being designed by the NSA?

• No security flaws or backdoors have been found in 20 years

• It is the only hash function available

• It is the fastest hash function

• It has a backdoor that only the NSA can access

What is the significance of collision resistance in hash functions?

• It ensures the hash function is fast

• It prevents two different inputs from having the same hash

• It makes the hash function deterministic

• It allows easy reversibility of the hash