Welcome to this final post.
Here we will discuss some ways to crack the password hashes.
Suppose, you have got a hash string (a random looking string) which corresponds to some password. Now what can be the ways to 'crack' the original plaintext from this hash? Think yourself.
Intuitively, there seem three possible ways:
1- To try to match the given hash, with the hash of each and every possible character or string in the world. Firstly, we will try hashes of all the characters, then of all the possible strings of length 2, then all possible strings of length 3, and so on... (doesn't that sound practically impossible!! But even that works manytimes; especially due to the advances in the processing power of today's computers.) This is called 'Brute-force' method.
2- To select few words (eg. in a wordlist) (like, the most probable passwords collection), and just check the hash of each of them with the given hash.
3- Using rainbow tables, which are precomputed hashes to word mappings of millions of words. The collection often sizes upto few terabytes. This can also be searched for a hash-match.
This is how password hashes are tried to be cracked.
The 'Tool' in the other tab can be used to crack an MD5 Hash using a Wordlist (a collection of words separated by semicolon). All it does is try to match the hashes of all of the given words in the wordlist with the given hash (hash which is to be cracked).
This last post marks the end of this series of short articles on Cryptography.
Hopefully, this was a nice journey for you, learning various cryptographic techniques - from classical easy ones to the wonderful and inspirational methods of the new age. Definitely, you would have gained greater insight into the world of Cryptography, which will help you not only become a better cryptography-aware citizen, but also pursue the field further if you want.
The career prospects as well as the new horizons in this discipline offer great future promises, which you can surely benefit.
In the end, it's a matter of huge proud that you have developed a new way of thinking, a new way of imagining. You have privileged yourself with the art and science of Message Concealment that was once considered a secret practice of Black art! Indeed, the effect that cyprotgraphy produces is no less magical than a miracle, and you, yourself, are no less wondrous than a wizard.
All the Best for your future ventures.