Binary hashing - what is it?
hash
Solution
Look at this page which describes CRC32 -good old Wikipedia
This is possibly the simplest hashing algorithm (certainly not the best!), but it should give you a general idea of how a hash works.
All the other hash algorithms do basically the same thing, but with algorithms that are either harder to reverse (sha256 etc.) or which give a more even distribution of results and less likelihood of a collision (perlhash etc).
Which is best depends on what you want the hash for:
- Proving a file was not tampered with --> sha256/512.
- Storing a password or other value you want to keep secret --> sha256/512
- Getting a numeric key for an array or database record from a string --> perlhash or similar.
- Quickly obfuscating or masking a account numbers --> crc32
Here is an excellent article describing the hash function used by the perl programming language bob burtle's hash
Problem
I am trying to understand what Binary hashing is. My understanding, is that you split your message into four parts, D1-D4, you then has each of those parts individually and get H1-H4. You then hash H1+H2 and H3+H4 to create H5 and H6. You then hash H5 and H6 to generate your final hash value, H. Is this correct? If not please tell me where I'm going wrong, thank you!