picoCTF 2021 easypeasy

one time pad encryption with XOR

[bobbyrandomguy]

Wow this one is interesting. Im so used to looking for "pico" or "CTF" or at least "{}" somewhere that I was really stumped. Glad u made these videos. Thanks for them!!

[larryphotography]

Wow!!! Man you are so fast and accurate. Thank you for making these, I learn so much from them

[Snakebloke]

Amazing, as usual. You're making this PenTest+ studying so much easier at the start.

I look forward to the day when I can work through these without assistance. Probably far closer now that I'm able to see your content. <3

[TimelessFlavour]

The lambda function that you understood immediately took like 30 minutes to grasp for me. After learning it was bitwise xor I gave up. Thanks for sharing this.

ps. I wonder how can a guy be so tech savvy and use right click to copy paste...

[samuelbrice]

Silly question but you did and I wasn't sure what this {:x} is supposed to be doing?

[yourpriaidaman]

Hi, sorry for being late but I do have a question in regard.

What does completing the 50000 len has to do with the plaintext a's that you did? I am pretty much lost there.

If I were to just key in 32 length of a's, would it be any different?

[extncti]

Little bit of a stupid question, but I am really trying to understand in depth what you are doing so i can do it myself one day. When you go "python -c" what does the "-c" actually do?

[cipher]

Definitely not a Easy Peasy 40 point challenge to me. I solved some 100+ point challenges in seconds, I was stuck on this

[Павал-лч]

As an option, you can '\0' * 32 and you won't have to xor with 0x61, because it will get you the key.
I used similar approach but I sent '\0'*50000 at once and cut 64 symbols from the end. It worked when I ran otp.py on my machine, but it did not work using nc. I wonder what might be the problem.

[Mango-Man]

'{:x}'.format(ef^ea^pa) can you explain this line and why does print(ef^ea^pa) does not work

[mohammedbahamid]

After getting the length which is "64", I got stuck and I could not use the command after that. I kept getting the 3 arrows syntax and I could not move from there. Do u know why?

[汝風留名]

I am not familiar with the bitwise operations. I would like to know if ef = f ^ k, ea = pa ^ k, how do you know that ef ^ ea = pa ^ f ?
If there are any resources or websites that u could suggest to learn bitwise operations, it will be much appreciated!

[siapahayoo]

how can you know the pad they used is the last pad?

[schatten-]

Can you explain the command: python -c "print('a'*49968); print('a'*32)"? Why you do that?
Thank you so much!

[rlsn-kali]

why you don't just multiply the 'a' by 50000 instead of 49968 then 32?

[pepesugimiosan]

hi, wouldn't you retrive the password if instead of the last 32 a you use the encripted password you got at the begininning? i tought so but this solution doesn't seems to work but i'm not understanding why

[سيفالشمري-ضثو]

Hi why u dont use linux ? Wont it be easier ?