In short
Hashing turns data of any size into a fixed-length value (a hash) using a one-way function. Any change to the data produces a different hash, so hashes are used to check integrity.
Key takeaways
- A hash can't be reversed to recover the original data.
- Systems store hashes of passwords rather than the passwords themselves.
- Digital signatures sign a hash of the document.
Where it's tested
ISC: Information Security Fundamentals — study notes, a five-minute revision sheet and practice questions.
Practise: 3 questions
Question 1 of 3 · 0 answered
What property of a cryptographic hash function makes it useful for checking that a file has not been altered?