What Is a Cryptographic Hash Function?
A cryptographic hash function is a mathematical algorithm that takes an input of any size and produces a fixed-length output. This output, known as the message digest or hash value, is used to verify the integrity of data by ensuring it has not been modified in transit. The most common use for cryptographic hashes is to create digital signatures which can be used to authenticate documents or messages. Cryptographic hashes are also used in password storage systems where they help protect user passwords from being revealed even if the system’s database is compromised.
Cryptographic hash functions have several important properties that make them useful for security applications. They must be deterministic so that given an identical input, they will always produce the same output; they should be one-way meaning it should be difficult to determine what the original input was based on its corresponding message digest; and finally, they should have collision resistance meaning two different inputs cannot generate the same message digest. These properties ensure that cryptographic hashes remain secure against malicious attacks such as brute force attempts at guessing passwords or tampering with data during transmission over networks.