COMPUTER FUNDAMENTALS

Detailed explanation-1: -A hash function, is a function that takes some message of any length as input and transforms it into a fixed-length output called a hash value, a message digest, a checksum, or a digital fingerprint.

Detailed explanation-2: -A one-way hash function, also known as a message digest, is a mathematical function that takes a variable-length input string and converts it into a fixed-length binary sequence that is computationally difficult to invert-that is, generate the original string from the hash.

Detailed explanation-3: -Most cryptographic hash functions are designed to take a string of any length as input and produce a fixed-length hash value. A cryptographic hash function must be able to withstand all known types of cryptanalytic attack.

Detailed explanation-4: -Hash function coverts data of arbitrary length to a fixed length. This process is often referred to as hashing the data. In general, the hash is much smaller than the input data, hence hash functions are sometimes called compression functions.

Detailed explanation-5: -Hash functions are used for data integrity and often in combination with digital signatures. With a good hash function, even a 1-bit change in a message will produce a different hash (on average, half of the bits change). With digital signatures, a message is hashed and then the hash itself is signed.