## Codepath CYB 101 Week 1 Lab Guide

**Exercise 1: Let's decode!**

1. See the message - "Terng wbo qrpbqvat lbhe svefg pvcure!" right? It seems that the letters might have been shifted.
2. If you go to cyber chef and try ROT 13, a shift cipher you see the flag pops up!
Flag - Great job decoding your first cipher!

**Exercise 2: Let's Build a Fence! Wait ... I Need a !#CTOAHDPE!# Key!**

1. Well the message is - "Acx'vt dhppu dqpzbui! Yhie im br!". It says that this is a polyalphabetic cipher but needs a key.
2. But if you see the title it gives the key! But still doesn't make any sense. If you look closely though, this actually looks a word you might know.
3. Actually the key is a word everyone knows. If you use a transposition cipher like rail fence cipher, you actually decrypt the key - "CODEPATH".
4. Great! So let's use the key and try a polyalphabetic cipher like Vigenere cipher. When we do that with our decrypted key " CODEPATH", we get the flag-
"You're doing amazing! Keep it up!"

**Exercise 3: Is a ROT13 Always a Shift of 13?**

1. In this challenge, this challenge is to decode the message - "Ijhtinsl rjxxfljx nx kzs, gzy bmfy jqxj hfs bj it?!". But, it seems we need to go further with ROT13.
2. And, if you work try changing all the properties with ROT13 and really try changing the amount, you will see you actually come up with the flag-"Decoding messages is fun, but what else can we do?!"
3. Alternatively, you can also try ROT 13 brute force and still get the flag.

**Exercise 4: Broken File Image**

1. Hmm, we do have an image that is in png format but that does not show up. Strange, in fact we actually take a look at its values then.
2. Well, it does say about magic numbers - file headers that actually determine the format of the file. Let's try to open up the hex values of the image with Cyberchef.
3. Well, looks very confusing at first but let's read what hex values actually form the png files from the magic numbers they have given.
4. Since it looks that the first four bits of a png file are different, maybe let's try to change the first four bits and see if it helps us to show the image.
5. Yep, and the image shows up. This is what you would get in that image-

**Exercise 5: Hidden Message**

1. Ok, so let's jump into some extracting messages from a file. It seems that we have a hidden message in this image but we just have to figure out how we can find it.
2. Well, it doesn't seem maybe something is in there at first. But let's use cyberchef to help us find the image.
3. Let us try changing the background color of the image to something else if that helps. We might try a forensics tool called Randomize Color Palette.
4. If we try that, we see that image actually shows up. It should say - "I am impressed." So yep, we got our flag.

**Exercise 6: Hashes Anyone?**
1. Phew! A lot of exercises done, but still have one more left. In this challenge, we talk about hashes. So we have a message to decipher-"Qfw ech'uv rkoqb wox huh gruxrfk!" but wait, the key looks very gibberish. Key: 8621ffdbc5698829397d97767ac13db3
2. Maybe they are talking about hashes, so the key might be actually encrypted with a hash. To check that we use a tool called crackstation.

3. Yep, we see that the key was actually hashed. So, we know have the key and we can work on the cipher.
4. Let us try vigenere cipher and using the key "dragon" we just got, let us try to decrypt the message.
5. It worked! Yep, we did it and this is what you should get for the flag- 

So, now you have everything, it is time to work on the project.