In digital forensics, we never modify original evidence. We create a Cryptographic Hash to verify that the data has not been altered.
1. Type a sentence above.
2. Look at the hashes generated on the right.
3. Change ONE character (e.g., change a period to a comma).
4. Observe the "Avalanche Effect"—the entire hash changes drastically!
If two users have the same password (e.g., "123456"), they would normally have the same hash.
Hackers use pre-computed lists of hashes called Rainbow Tables to crack these instantly.
To fix this, we add a random string called a Salt to the password before hashing it.
The hashes above are generated from the "Final String".
Unlike encryption, hashing cannot be reversed. You can turn "password" into a hash, but you cannot mathematically turn the hash back into "password".
If two different files produce the same hash, it's called a "collision." MD5 and SHA-1 have known collision vulnerabilities, which is why we prefer SHA-256.
Notice the length difference? A 256-bit hash (SHA-256) is significantly longer than MD5, making it exponentially harder for attackers to brute-force.