Challenges

Functionals were used to write this crackme, hopefully your decompiler handles it well.

https://cybersharing.net/s/51e6db3f2efbe295 Output with actual flag is 19 6 3e 3e 6c 34 36 99 19 32 58 33 ba 9c b1 e6 36 b 69 89 c6 58 8c b5 26 31 19

Randall would be proud.

https://cybersharing.net/s/218b97038cce7279

Watch out for holes... Hint:

• The challenge is based on linearly recurrent sequences
• The "holes" correspond to 0s in the coefficients of A's minimal polynomial

https://cybersharing.net/s/db6d6b915ec807ab5edc9085f548444b

What a beautiful painting my computer created! Can you glean the artist's message?

When you find the flag, it will be in ICTF format instead of ictf. STILL SUBMIT USING ictf{} FORMAT. It may take some time (depending on implementation) for your computer to solve this challenge.

https://cybersharing.net/s/b480dd6401d262a2

No source... can you find the attack? Hint: sum of digits in CVE is 26.

https://cybersharing.net/s/c257cd0eeb221a80ac8180246ed0c5bf

two pads and no plaintext surely this is secure...

https://cybersharing.net/s/b32497ad5c8e3129

TIL that music can have messages wow! Your flag should be in all lowercase. You figure out the spacing 😃

https://cybersharing.net/s/a2f2dceb889d71a38c3faf01ec02e9fb

Two time pad????

https://cybersharing.net/s/feffe36ab6e0fe0543115274087348fa

You'll never be able to guess my seed!

https://cybersharing.net/s/3fa636f5264466f3

This challenge is to guess a number guarded by a very snarky code-commenter. Wrap it in the flag format for submission. Example: ictf{1337244835594660}

(python version 3.10.12 btw)

https://cybersharing.net/s/1be0e77ecacfd78d5c675546d6e83208

HR has notified me that the use of CyberChef to make challenges is not ideal to the general CTF playerbase. Therefore, I present you an anti-cyberchef-handmade-challenge!

}!resb_kkz_qne_smdldqhtpdq_z_da_cktngr_rkkzgb_xrrdtf_mnm{esbh

Figure it out.

nc 155.248.210.243 42193 https://cybersharing.net/s/f993282e13db635e4bcb9d44bae64ab7

Given a list of integers a, count the number of positive integers x that cannot be expressed as sum([a[i]*b[i] for i in range(len(a))]) for some list b of len(a) nonnegative integers. (python notation)

nc 155.248.210.243 42173 https://cybersharing.net/s/7e1e82ce619b74e617fbb981eb04e96d

Such creative OSINT titles.

For the flag, submit the name of the "road" on Google Maps where the photo was taken from, using all lowercase and underscores. Example: ictf

https://cybersharing.net/s/5df1773efccd5333d5a598b91fe81c1d

Welcome to round 51!

ictf{W3lcome_TO_RoUNd_51!!!!!}