add mathjax 2

_posts/2024-10-20-malware-cryptography-33.markdown

@@ -28,7 +28,7 @@ At the request of my readers, I would like to remind you what the Feistel networ
 
 The Feistel network is a block encryption technique created by Horst Feistel at IBM Labs in 1971.    
 
-The Feistel network is a block cipher structure that processes data by splitting each block into two equal parts: the left (`L`) and right (`R`) subblocks. 
+The Feistel network is a block cipher structure that processes data by splitting each block into two equal parts: the left \\( L \\) and right \\( R \\) subblocks. 
 The left subblock is transformed using a function: \\[ x = f(L,K) \\] where \\( K \\) represents the key. This function can be any cryptographic operation, such as a shift cipher.     
 The transformed left subblock is then XORed with the unchanged right subblock: \\( x = x \oplus R \\).    
 After this, the left and right subblocks are swapped, and the process repeats for multiple rounds.