# Level 2: Fixed XOR
## Task
Write a function that takes two equal-length buffers and produces their XOR combination.
If your function works properly, then when you feed it the string:
```
1c0111001f010100061a024b53535009181c
```
... after hex decoding, and when XOR'd against:
```
686974207468652062756c6c277320657965
```
... should produce:
```
746865206b696420646f6e277420706c6179
```
***
### Explanation
#### What is Fixed XOR?
XOR is a binary operation. Essentially, two bits are compared. If they are the same, the result is 0; otherwise, the result is 1.
Example
* 0 + 0 = 0
* 1 + 0 = 1
* 0 + 1 = 1
* 1 + 1 = 0
"Fixed" means that both strings have the same length.
{% hint style="info" %}
You can learn more about XOR by reading [my article](https://www.linkedin.com/posts/patricioburattini_xor-the-simple-operation-behind-major-activity-7308565249832415232-EMSB?utm_source=social_share_send\&utm_medium=member_desktop_web\&rcm=ACoAACzoH-4BxIxxWtPU_MQNMwjumdgLCzeG5BA) on linkedin
{% endhint %}
***
### Resolution
First, we are going to create a file named `task2.py`
#### Understanding the code
* *binascii* library is imported to manipulate hexadecimal data.
* After that, `fixed_xor` function is defined, which takes two parameters
* `hex1`, which contains the first hex string.
* `hex2`, which contains the second hex string.
* `bytes1` and `bytes2` store the byte representation of `hex1` and `hex2`, respectively.
* The variable `xored_bytes` stores the XOR result by following these steps
* `zip(bytes1, bytes2)` is a Python function that pairs elements from both byte sequences.
* Example: a = \[1, 2, 3] b = \['x', 'y', 'z']. `zip` returns \[(1, 'x'), (2, 'y'), (3, 'z')
* `a ^ b for a, b in`` ``zip(bytes1, bytes2)` is a Python expression that iterates through both byte sequences and applies XOR(^) to each pair of bytes.
* `bytes()` is a Python function that takes an iterable and returns a `bytes` object.
* Next, `hex1` and `hex2` are initialized with their respective strings.
* The variable `resultado` stores the result of `fixer_xor(hex1, hex2)`.
* Finally, `resultado` is printed
***
### Result
