# BRONCO CTF 2025 WRITE-UPS Welcome to my BRONCO CTF 2025 write-ups. This is my third international CTF that I have competed in. Though I could only solve two challenges in this competition, any solved challenges have to be written down. ## Table of Contents 1. Cryptography a. Across the Tracks 2. OSINT a. Filing Some Data ## 1. Cryptography ### a. Across the Tracks ![Challenge Page](https://hackmd.io/_uploads/HyivpWMcJl.png) In my opinion, this challenge was quite easy since the hint of the cipher was already given in the descriptions. If you're familiar with the words "railroad" and "fence", then you can assume that this challenge used rail fence cipher to encode the messages. As I always did, I used cryptii.com to decode a simple cipher like this one. ![Step 1 (Decoding The Messages Directly)](https://hackmd.io/_uploads/SkVlefGcyx.png) By trying various keys to decode it, I found that the 12th key gave you the plaintext message that was encoded. Flag: bronco{r@1l_f3nc3_cip3rs_r_cool} ## 2. OSINT ### a. Filing Some Data ![Challenge Page](https://hackmd.io/_uploads/rkDnTzfqke.png) This challenge requires me to find the filing number of a restated article of Jesuit School of Theology of Santa Clara University. At first, I didn't know what and how to do this challenge. So I asked ChatGPT for some help. ![Step 1 (Asking ChatGPT For Some Help)](https://hackmd.io/_uploads/BJ10h3B9yl.png) ChatGPT gave me this link https://bizfileonline.sos.ca.gov/search/business to help me did my research. Without further ado, I clicked the link and searched through the website for Jesuit School of Theology of Santa Clara University specified article. ![Step 2 (Finding The Article)](https://hackmd.io/_uploads/rJQWZpr5kx.png) After finding the correct article, I clicked on "view history" to dig even further. ![Step 3 (Finding The Restated Article)](https://hackmd.io/_uploads/rJOA-6S5Je.png) As you can see, there many different articles. But there was one that caught my attention, which was "Restated Articles of Incorporation" since the challenge asked me to find the restated article of Jesuit School of Theology of Santa Clara University. By clicking the restated article, I got this information. ![Step 4 (Restated Article Information)](https://hackmd.io/_uploads/BJ9lEarckg.png) Concluding that the legacy number was the filing data, I wrapped it inside the bronco{} flag format and solved the challenge. Flag: bronco{A0693181} Solved two challenges for BRONCO CTF 2025. Not bad, but still have to improve. With heartfelt grace, I treasure your kind regard for my write-up, as words find solace in the eyes that cherish them. "Through veils of dusk, I take my leave, A silent ghost in midnight’s weave. No chains to bind, no path to stay, Like fleeting rain, I fade away. Yet should the storm call out my name, In echoes lost, but not in shame, BLACKRAIN departs with whispered sigh, Not forever—just goodbye. BLACKRAIN (STELK_CSC), BRONCO CTF 2025, Santa Clara, United States of America.