Hide to See - 100 pts
Description
How about some hide and seek heh?Look at this image here .
Approach
The image hinted at the Albash cipher, but I didn’t found any encrypted data. After examining the metadata and trying different steganography tools, I eventually discovered the encrypted data hidden within the image using steghide.
┌──(kali㉿iasad)-[~/CTFs/PicoCTF]
└─$ steghide extract -sf atbash.jpg
Enter passphrase:
wrote extracted data to "encrypted.txt".
┌──(kali㉿iasad)-[~/CTFs/PicoCTF]
└─$ cat encrypted.txt
krxlXGU{zgyzhs_xizxp_1u84w779}
decoded it on Atbash Cipher and got the flag
Flag: picoCTF{atbash_crack_1f84d779}
ReadMyCert - 100 pts
Description
How about we take you on an adventure on exploring certificate signing requests
Take a look at this CSR file here
Hint💡
Download the certificate signing request and try to read it.
Approach
Dumping the contents of the readmycert.cer file reveals:
-----BEGIN CERTIFICATE REQUEST-----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-----END CERTIFICATE REQUEST-----
Looks base64 encoded, running through CyberChef the flag is found in amongst the decoded output :
Flag: picoCTF{read_mycert_a7163be8}
Rotation - 100 pts
Description
You will find the flag after decrypting this file Download the encrypted flag here
Hint💡
Sometimes rotation is right
Given the name of this challenge, a rotation-based substitution cipher is suspected.
Approach
The contents of the encrypted flag file are:
xqkwKBN{z0bib1wv_l3kzgxb3l_25l7k61j}
The encrypted text follows the flag structure picoCTF{}
We can use CyberChef to find the plaintext. By applying ROT13 operation, and adjesting the amount to 18 we get the Flag
Flag: picoCTF{r0tat1on_d3crypt3d_25d7c61b}