TryHackMe — Hashing Basics | Cyber Security 101 (THM)

Hash Functions

1. What is a Hash Function?
   A hash function takes any input size and produces a fixed-size summary, making it nearly impossible to reverse from output to input. Even small changes in input cause significant changes in output.
2. Example:
   Comparing two files, one with the letter T and one with U (differing by one bit), produces completely different hash values.
3. Importance of Hashing:
   Hashing ensures data integrity and confidentiality, particularly for passwords. Instead of storing passwords, systems store hash values and compare them to verify correctness.
4. Hash Collision:
   Collisions happen when different inputs produce the same hash output. Hash functions like MD5 and SHA1 are now insecure due to known collision vulnerabilities.

Questions and Answers

1. What is the SHA256 hash of the passport.jpg file in ~/Hashing-Basics/Task-2?

• 77148c6f605a8df855f2b764bcc3be749d7db814f5f79134d2aa539a64b61f02

1. What is the output size in bytes of the MD5 hash function?

• 16

1. If you have an 8-bit hash output, how many possible hash values are there?

• 256

Insecure Password Storage for Authentication

1. Hashing in Authentication:
   Hashing is used in authentication to confirm password knowledge without revealing the actual password.