In the context of computing, a hash is a function that converts an input (or ‘message’) into a fixed-size string of bytes. The output, typically a hexadecimal or base64-encoded string, is a unique representation of the input data.
Hash functions are commonly used in various applications, such as cryptography, data retrieval, and data validation. They are designed to be fast and efficient, producing a unique hash value for each unique input. Even a small change in the input data should produce a significantly different hash value.
Example:
import hashlib
# Create a SHA-256 hash object
hash_object = hashlib.sha256()
# Update the hash object with input data
data = b'Hello, World!'
hash_object.update(data)
# Get the hexadecimal digest of the hash
hash_digest = hash_object.hexdigest()
print(hash_digest)