Hey guys and welcome to a new series
We will start with cryptography
So...Why do we want to start with cryptography?
Firstly, we do have some hacking videos and they are pretty lit. Also, for hacking you normally need a basic knowledge of cryptography
Secondly, I also did some videos dealing with theoretical IT and cryptography also is part of that because you will use it a lot
And I want to produce a lot of videos for this playlist
I hope you are as hyped as I am. Let me know about it
Exactly. So let's directly start with a pretty ancient algorithm, so called the "Caesar-Cipher".
For those of you, who aren't that much into English, "Caesar" is a weird pronunciation of "Cäsar" and "Cipher" basically means "Encryption" or "Chiffrat". "Chiffrat" is German for "encrypted message"
So, when I talk about a Cipher, I mean the encrypted part and when I'm talking about the message, I mean the original text, which isn't encrypted and readable for everyone
For example, Ceaser said:"Greift die Gallier an."("Attack the Gauls). This would be the plain text and if the Gauls would get it in their hands they maybe would have a problem, because they don't understand Latin
But if they could understand it, they would know about Caesar's plans about attacking them and would be able to prepare themselves
This would be pretty fatal for Caesar
And Caesar was a clever man and thought about a Cipher
Then he encrypted the message so nobody but his groups and himself could read it
This was a very common Cipher and they unified the number 3
But it would also work with any other number although we also use the 3
The sense behind it was that we are writing everything without the spaces and also leave out the dot.
They also normally didn't use a dot, because the Latins were a little bit weird.
They didn't use a dot or comma and so on, however.
Sometimes they did use them but that doesn't matter now
Anyway, we will use every single letter and shift it on for 3 letters in the alphabet and when we reach 'z', we just start at 'a' again
Let's say...a,b,c,d,e,f,g,h,i,j,k and so on - you all know it - 'g' shifted 3 letters backwards is...
Or, I will write it down first [alphabet]
So know I can demonstrate it better for you
We are here right now and we want to shift it 3 to the right. One, two, three.
So we will be at 'j', okay
Let's do the same thing for 'r'. One, two, three and take the 'u'
And for 'e'. One, two, three and we will take the 'h'. And so on
I will complete it for you...
So here I am again. So this Cipher isn't readable anymore and you can't see if he will attack the Gauls or just grabs his stuff and goes home again
Uhm, yes. Pretty convenient but also very easy to crack.
If you know the number 3, you can just shift it back again. So from 'j' back to... One, two three and we will be at the 'g' again
If you go on like that you will have the plain text again
The Gauls weren't that dump of course, so they found it out pretty quickly, or not. I don't know
However, even when you don't know the number 3, you could just bruteforce the Cipher from 1 to 26 for every single letter of the alphabet
So you shift the 'a' to the 'b' and then to the 'c' if it isn't correct and then the 'd','e',... until you got to 'z'
Then you have a few possibilities how to decrypt the text and that works pretty fast
That's why this variety wasn't to successful
And in this series, I want to teach you better procedures and later on we really will use mathematical operations, we are using everywhere
With our PCs when we are communicating, when you access a website with HTTPS
And nowadays, everything uses HTTPS, which is usefull
So I hope you will be motivated to see more and do not forget to give a like or to subscribe to my channel. See you soon.
