binhexa

Challenge Description

We begin by connecting to the server by running nc titan.picoctf.net 61359.

Binary operations

We are greeted with a barrage of questions related to binary operations. Once we answer the 6 questions and enter the results of the last operation in hexadecimal, we are awarded with the flag.

For this challenge, I used a python script to assist with the binary operations:

Python script for basic binary operations

I’ve included some comments as well to explain the binary operations.

binary_number_1 = 0b00111010  
binary_number_2 = 0b00101001 
 
# Question 1: Right shift binary_number_2 by 1
print(f'{binary_number_2 >> 1:08b}')
# Output: 00010100 (Right shift by 1 divides by 2)
 
# Question 2: Bitwise OR between binary_number_1 and binary_number_2
print(f'{binary_number_1 | binary_number_2:08b}')
# Output: 00111011 (OR operation combines bits, 1 if either bit is 1)
 
# Question 3: Bitwise AND between binary_number_1 and binary_number_2
print(f'{binary_number_1 & binary_number_2:08b}')
# Output: 00101000 (AND operation, 1 if both bits are 1)
 
# Question 4: Multiplication of binary_number_1 and binary_number_2
print(f'{binary_number_1 * binary_number_2:08b}')
# Output: 1110100010 (This result exceeds 8 bits; it will show as a larger binary number)
 
# Left shift binary_number_1 by 1
print(f'{binary_number_1 << 1:08b}')
# Output: 01110100 (Left shift by 1 multiplies by 2)
 
# Addition of binary_number_1 and binary_number_2
print(f'{binary_number_1 + binary_number_2:08b}')
# Output: 01100011 (58 + 41 = 99 in decimal, which is 01100011 in binary)
 
# Hexadecimal representation of the addition
print(f'{binary_number_1 + binary_number_2:x}')
# Output: 63 (99 in decimal is 63 in hexadecimal)

After submitting the 6 correct answers, the flag will be revealed.

Flag

picoCTF{b1tw^3se_0p3eR@tI0n_su33essFuL_6862762d}