 We are back looking at the tutorial number two of the Pico CTF just getting into learning how to be a Hacker someone in the capture the flag scene So we're checking out tutorial number two is our challenge title our challenge prompt is Robin handed me this the other day Maybe it'll help me find the answer So the hints here are there are a number of solvers on the internet that can help Okay, so let's check this link that this icon that that this text and we can remove that control f thing from the last Challenge this says hey check out the super secret message. I made using this cool rot-13 cipher. I found online Lubella fuba you know blah blah blah lots of nonsense and garbage Okay, so this is where we've got to start to do our own learning our own Getting out of our comfort zone making some research happen googling and trying to understand what we're really looking at right here so rot-13 cipher that's Apparently whatever this text is this this nonsense. So I'm gonna go ahead and go to Google right again voting for Google not for Bing I Didn't want to see that happen again. So rot-13. What is that? Rot-13. Here's a Wikipedia page rot-13 rotate by 13 places sometimes hyphenated rot-13 is a simple letter Substitution cipher that replaces a letter with the 13th letter after it in the alphabet Rot-13 is a special case of the Caesar cipher which was developed in ancient Rome. Huh, okay Because there are 26 letters 2 times 13 in the basic alphabet rot-13 is its own inverse That is to undo rot-13 the same algorithm is applied So the same action that can be used for encoding and decoding this provides virtually no Cryptographic security. It's often cited as the connect canonical example of weak encryption Okay, I guess that's why we're seeing it in a beginner kind of early on friendly capture-the-flag competition that's gonna be probably the smallest like the first place to start the foundations of cryptography and Cyphers so we can see this picture over here. You see a is mapped to n b is mapped Oh, etc. etc. And that happens because they're being translated or kind of Rotated by 13 places Rot-13 replaces each letter by its partner 13 characters further along the alphabet they use hello as an example, etc And there's more here more here another link that I saw back in the Google results was this rot-13 com Looks like please enable JavaScript to use this page Whatever looks like Would this just okay cool looks like it's a tool or utility that will let us Like try out the cipher. So if I were to type in anything like please subscribe You can see down below. Here's that Rot-13 version of it. But remember it said in the Wikipedia page that to Like encode or decode or once we have it, please subscribe encoded is this But if we were to decode it, we give it the exact same thing. So if I just cut If I just copy or paste this string Will let me cut whatever whoa Maybe I was out of that because of uh Whatever my keyboard is trying to do we don't need it Okay, let's paste it in just at the top there. So that's the input to the rot-13 algorithm and you can see it down below Please subscribe. That's the output because encoding and decoding is the same. It's just that Operation rotate-13 is going to be the same after we rotate 13 times again since it said in that Wikipedia page We know there are 26 letters in the alphabet. So, okay We can just take that string. They gave us so that long piece of text. You'll hear me call them a string a lot and That that will be what we're looking for if we pass it into that rot-13 tool if I can click over to that tab Okay Sorry, this virtual machine is pretty clunky. So let's paste that in Totally didn't take it because my keyboard also does not want to correspond with me Let's paste that in there we go and here we go. We see yo Have you been playing that new meso pets game the new blah blah blah? I would go Sephora saying it's my new life's dearest ambition to obtain an inflatable sloth monster Okay, maybe this is the flag. This must be what we're trying to submit for points Let's go over here to that page pico CTF 2017 and Let's submit this flag Submit down the bottom right cool looks like we're moving on that was the correct answer and now we learn something new Right, so rot-13 is a derivative or a special case of the Caesar cipher and that Caesar cipher It's using a key in this cryptographic session of any number less than the Number of letters in the alphabet, right? So that means it's mod 26 or its modulus 26 because there are only 26 characters in the alphabet the key can only be Anywhere in that range from 0 to 26 so mod being a remainder of 26 it will wrap around 0 to 26, etc So in this case rot-13 is that special case It's using 13 as of the key a goes to and etc. You saw that Because 13 is that halfway point of the alphabet. It's half of 26, right? So cool We're done with that one and now we can move on to tutorial number three Sweet. Thank you guys for sticking with me. Hope you enjoyed this Simple stuff, right? We're still not doing any of the crazy cool lead hacks yet But we're gonna get there super duper soon. We're right now. We're building out the the basics We're on the building blocks to level out that foundation where we can grow from so thank you guys for sticking with me I'll see you in the next tutorial and hey, I just got a shout-out all my supporters The people that'll love me on patreon Spencer Clark gal Horowitz says okay Attila and Orga loft you unruly destroy of world's bastion of terror Sweet hey $1 a month just patreon will give you that shout out the end of the video get your name up here $5 a month tools early access to any of the videos content that I create for the future So it's not you can get them as quickly as I release them not waiting on YouTube to pump them out and hey If you did like this video, please do press that like button. 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